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PowerShell

PowerShell is a powerful interactive command-line interface and scripting environment included in the Windows operating system. [1] Adversaries can use PowerShell to perform a number of actions, including discovery of information and execution of code. Examples include the Start-Process cmdlet which can be used to run an executable and the Invoke-Command cmdlet which runs a command locally or on a remote computer.

PowerShell may also be used to download and run executables from the Internet, which can be executed from disk or in memory without touching disk.

Administrator permissions are required to use PowerShell to connect to remote systems.

A number of PowerShell-based offensive testing tools are available, including Empire, PowerSploit, [2] and PSAttack. [3]

PowerShell commands/scripts can also be executed without directly invoking the powershell.exe binary through interfaces to PowerShell's underlying System.Management.Automation assembly exposed through the .NET framework and Windows Common Language Interface (CLI). [4][5] [6]

ID: T1086
Tactic: Execution
Platform: Windows
Permissions Required: User, Administrator
Data Sources: PowerShell logs, Loaded DLLs, DLL monitoring, Windows Registry, File monitoring, Process monitoring, Process command-line parameters
Supports Remote:  Yes
Contributors: Praetorian
Version: 1.1

Procedure Examples

Name Description
APT19 APT19 used PowerShell commands to execute payloads. [64]
APT28 APT28 downloads and executes PowerShell scripts. [69]
APT29 APT29 has used encoded PowerShell scripts uploaded to CozyCar installations to download and install SeaDuke. APT29 also used PowerShell scripts to evade defenses. [16] [53] [54]
APT3 APT3 has used PowerShell on victim systems to download and run payloads after exploitation. [65]
APT32 APT32 has used PowerShell-based tools, PowerShell one-liners, and shellcode loaders for execution. [48] [49] [50]
APT33 APT33 has utilized PowerShell to download files from the C2 server and run various scripts. [97]
AutoIt backdoor AutoIt backdoor downloads a PowerShell script that decodes to a typical shellcode loader. [13]
BONDUPDATER BONDUPDATER is written in PowerShell. [14] [35]
BRONZE BUTLER BRONZE BUTLER has used PowerShell for execution. [89]
Cobalt Group Cobalt Group has used powershell.exe to download and execute scripts. [77] [78] [79] [80] [81] [82]
Cobalt Strike Cobalt Strike can execute a payload on a remote host with PowerShell. This technique does not write any data to disk. [7]
CopyKittens CopyKittens has used PowerShell Empire. [63]
DarkHydrus DarkHydrus leveraged PowerShell to download and execute additional scripts for execution. [19] [68]
Deep Panda Deep Panda has used PowerShell scripts to download and execute programs in memory, without writing to disk. [72]
DownPaper DownPaper uses PowerShell for execution. [18]
Dragonfly 2.0 Dragonfly 2.0 used PowerShell scripts for execution. [83] [84] [85]
Emotet Emotet has used Powershell to retrieve the malicious payload and download additional resources like Mimikatz. [36] [37] [38] [39] [40]
Empire Empire leverages PowerShell for the majority of its client-side agent tasks. Empire also contains the ability to conduct PowerShell remoting with the Invoke-PSRemoting module. [11] [12]
FIN10 FIN10 uses PowerShell for execution as well as PowerShell Empire to establish persistence. [55] [11]
FIN6 FIN6 has used a Metasploit PowerShell module to download and execute shellcode and to set up a local listener. [58] [59]
FIN7 FIN7 uses a PowerShell script to launch shellcode that retrieves an additional payload. [17] [56]
FIN8 FIN8's malicious spearphishing payloads are executed as PowerShell. FIN8 has also used PowerShell during and. [86] [87]
Gallmaker Gallmaker used PowerShell to download additional payloads. [96]
Gorgon Group Gorgon Group malware can use PowerShell commands to download and execute a payload and open a decoy document on the victim’s machine. [90]
HALFBAKED HALFBAKED can execute PowerShell scripts. [17]
HAMMERTOSS HAMMERTOSS is known to use PowerShell. [31]
Helminth One version of Helminth uses a PowerShell script. [33]
JCry JCry has used PowerShell to execute payloads. [45]
KeyBoy KeyBoy uses PowerShell commands to download and execute payloads. [44]
KONNI KONNI used PowerShell to download and execute a specific 64-bit version of the malware. [22]
Leviathan Leviathan has used PowerShell for execution. [61] [62]
Magic Hound Magic Hound has used PowerShell for execution and privilege escalation. [75] [76]
menuPass menuPass uses PowerSploit to inject shellcode into PowerShell. [88]
Mosquito Mosquito can launch PowerShell Scripts. [23]
MuddyWater MuddyWater has used PowerShell for execution. [91] [92] [93] [94] [27] [95]
OilRig OilRig has used PowerShell scripts for execution, including use of a macro to run a PowerShell command to decode file contents. [14] [70] [71]
Patchwork Patchwork used PowerSploit to download payloads, run a reverse shell, and execute malware on the victim's machine. [66] [34]
Poseidon Group The Poseidon Group's Information Gathering Tool (IGT) includes PowerShell components. [57]
POSHSPY POSHSPY uses PowerShell to execute various commands, one to execute its payload. [32]
POWERSOURCE POWERSOURCE is a PowerShell backdoor. [28] [29]
PowerSploit PowerSploit modules are written in and executed via PowerShell. [9] [10]
PowerStallion PowerStallion uses PowerShell loops to iteratively check for available commands in its OneDrive C2 server. [47]
POWERSTATS POWERSTATS uses PowerShell for obfuscation and execution. [26] [27]
POWERTON POWERTON is written in PowerShell. [41]
POWRUNER POWRUNER is written in PowerShell. [14]
Pupy Pupy has a module for loading and executing PowerShell scripts. [8]
QUADAGENT QUADAGENT uses PowerShell scripts for execution. [21]
RATANKBA There is a variant of RATANKBA that uses a PowerShell script instead of the traditional PE form. [24] [25]
Revenge RAT Revenge RAT uses the PowerShell command Reflection.Assembly to load itself into memory to aid in execution. [42]
RogueRobin RogueRobin uses PowerShell for execution. [19] [20]
SeaDuke SeaDuke uses a module to execute Mimikatz with PowerShell to perform Pass the Ticket. [16]
Socksbot Socksbot can write and execute PowerShell scripts. [34]
Soft Cell Soft Cell used PowerShell for execution to assist in lateral movement as well as for dumping credentials stored on compromised machines. [105]
SQLRat SQLRat has used PowerShell to create a Meterpreter session. [46]
Stealth Falcon Stealth Falcon malware uses PowerShell commands to perform various functions, including gathering system information via WMI and executing commands from its C2 server. [67]
TA459 TA459 has used PowerShell for execution of a payload. [73]
TA505 TA505 has used PowerShell to download and execute malware and reconnaissance scripts. [101] [102] [103] [104]
TEMP.Veles TEMP.Veles has used a publicly-available PowerShell-based tool, WMImplant. The group has also used PowerShell to perform Timestomping. [98] [99]
Threat Group-3390 Threat Group-3390 has used PowerShell for execution. [60]
Thrip Thrip leveraged PowerShell to run commands to download payloads, traverse the compromised networks, and carry out reconnaissance. [74]
Turla Turla has used PowerShell to execute commands/scripts, in some cases via a custom executable or code from Empire's PSInject. Turla has also used PowerShell scripts to load and execute malware in memory. [51] [47] [52]
Ursnif Ursnif droppers have used PowerShell in download cradles to download and execute the malware's full executable payload. [43]
WIRTE WIRTE has used PowerShell for script execution. [100]
Xbash Xbash can use scripts to invoke PowerShell to download a malicious PE executable or PE DLL for execution. [30]
Zeus Panda Zeus Panda uses PowerShell to download and execute the payload. [15]

Mitigations

Mitigation Description
Code Signing Set PowerShell execution policy to execute only signed scripts.
Disable or Remove Feature or Program It may be possible to remove PowerShell from systems when not needed, but a review should be performed to assess the impact to an environment, since it could be in use for many legitimate purposes and administrative functions.

Disable/restrict the WinRM Service to help prevent uses of PowerShell for remote execution.

Privileged Account Management When PowerShell is necessary, restrict PowerShell execution policy to administrators. Be aware that there are methods of bypassing the PowerShell execution policy, depending on environment configuration.

Detection

If proper execution policy is set, adversaries will likely be able to define their own execution policy if they obtain administrator or system access, either through the Registry or at the command line. This change in policy on a system may be a way to detect malicious use of PowerShell. If PowerShell is not used in an environment, then simply looking for PowerShell execution may detect malicious activity.

Monitor for loading and/or execution of artifacts associated with PowerShell specific assemblies, such as System.Management.Automation.dll (especially to unusual process names/locations). [4][5]

It is also beneficial to turn on PowerShell logging to gain increased fidelity in what occurs during execution (which is applied to .NET invocations). [106] PowerShell 5.0 introduced enhanced logging capabilities, and some of those features have since been added to PowerShell 4.0. Earlier versions of PowerShell do not have many logging features. [107] An organization can gather PowerShell execution details in a data analytic platform to supplement it with other data.

References

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