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Obfuscated Files or Information

Adversaries 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. [1] 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. [2] Payloads may also be split into separate, seemingly benign files that only reveal malicious functionality when reassembled. [3]

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. [4] [5] [6]

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. [7] 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. [8]

ID: T1027

Tactic: Defense Evasion

Platform:  Linux, macOS, Windows

Data Sources:  Network protocol analysis, Process use of network, File monitoring, Malware reverse engineering, Binary file metadata, Process command-line parameters, Environment variable, Process monitoring, Windows event logs, Network intrusion detection system, Email gateway, SSL/TLS inspection

Defense Bypassed:  Host forensic analysis, Signature-based detection, Host intrusion prevention systems, Application whitelisting, Process whitelisting, Log analysis, Whitelisting by file name or path

Contributors:  Red Canary, Christiaan Beek, @ChristiaanBeek

Version: 1.0

Examples

NameDescription
ADVSTORESHELL

Most of the strings in ADVSTORESHELL are encrypted with an XOR-based algorithm; some strings are also encrypted with 3DES and reversed. API function names are also reversed, presumably to avoid detection in memory.[9][10]

APT19

APT19 used Base64 to obfuscate commands and the payload.[11]

APT28

APT28 encrypted a .dll payload using RTL and a custom encryption algorithm. APT28 has also obfuscated payloads with base64, XOR, and RC4.[10][12][13]

APT3

APT3 obfuscates files or information to help evade defensive measures.[14]

APT32

APT32 uses the Invoke-Obfuscation framework to obfuscate their PowerShell and also performs other code obfuscation.[15][16][17]

APT37

APT37 sends images to users that are embedded with shellcode and obfuscates strings and payloads.[18]

Bisonal

Bisonal's DLL file and non-malicious decoy file are encrypted with RC4.[19]

BlackOasis

BlackOasis's first stage shellcode contains a NOP sled with alternative instructions that was likely designed to bypass antivirus tools.[20]

Carbanak

Carbanak encrypts strings to make analysis more difficult.[21]

Cobalt Group

Cobalt Group obfuscated several scriptlets and code used on the victim’s machine, including through use of XOR.[22]

Comnie

Comnie uses RC4 and Base64 to obfuscate strings.[23]

CORESHELL

CORESHELL obfuscates strings using a custom stream cipher.[24]

CozyCar

The payload of CozyCar is encrypted with simple XOR with a rotating key. The CozyCar configuration file has been encrypted with RC4 keys.[25]

Dark Caracal

Dark Caracal has obfuscated strings in Bandook by base64 encoding, and then encrypting them.[26]

Daserf

Daserf uses encrypted Windows APIs and also encrypts data using the alternative base64+RC4 or the Caesar cipher.[27]

Dust Storm

Dust Storm has encoded payloads with a single-byte XOR, both skipping the key itself and zeroing in an attempt to avoid exposing the key.[28]

DustySky

The DustySky dropper uses a function to obfuscate the name of functions and other parts of the malware.[29]

Elderwood

Elderwood has encrypted documents and malicious executables.[30]

Elise

Elise encrypts several of its files, including configuration files.[31]

Emissary

Variants of Emissary encrypt payloads using various XOR ciphers, as well as a custom algorithm that uses the "srand" and "rand" functions.[32][33]

FELIXROOT

FELIXROOT encrypts strings in the backdoor using a custom XOR algorithm.[34]

FIN7

FIN7 has used fragmented strings, environment variables, standard input (stdin), and native character-replacement functionalities to obfuscate commands.[4][35]

FIN8

FIN8 has used environment variables and standard input (stdin) to obfuscate command-line arguments. FIN8 also obfuscates malicious macros delivered as payloads.[4][36]

FinFisher

FinFisher is heavily obfuscated in many ways, including through the use of spaghetti code in its functions in an effort to confuse disassembly programs. It also uses a custom XOR algorithm to obfuscate code.[37][38]

FruitFly

FruitFly executes and stores obfuscated Perl scripts.[39]

Gazer

Gazer logs its actions into files that are encrypted with 3DES. It also uses RSA to encrypt resources.[40]

GravityRAT

GravityRAT supports file encryption (AES with the key "lolomycin2017").[41]

Group5

Group5 disguised its malicious binaries with several layers of obfuscation, including encrypting the files.[42]

H1N1

H1N1 uses multiple techniques to obfuscate strings, including XOR.[43]

Helminth

The Helminth config file is encrypted with RC4.[44]

Hi-Zor

Hi-Zor uses various XOR techniques to obfuscate its components.[45]

HOMEFRY

Some strings in are obfuscated with XOR x56.[46]

Honeybee

Honeybee drops files with base64-encoded data.[47]

HTTPBrowser

HTTPBrowser's code may be obfuscated through structured exception handling and return-oriented programming.[48]

Hydraq

Hydraq uses basic obfuscation in the form of spaghetti code.[30][49]

InnaputRAT

InnaputRAT uses an 8-byte XOR key to obfuscate API names and other strings contained in the payload.[50]

InvisiMole

InvisiMole avoids analysis by encrypting all strings, internal files, configuration data.[51]

Invoke-PSImage

Invoke-PSImage can be used to embed a PowerShell script within the pixels of a PNG file.[52]

ISMInjector

ISMInjector is obfuscated with the off-the-shelf SmartAssembly .NET obfuscator created by red-gate.com.[53]

JHUHUGIT

Many strings in JHUHUGIT are obfuscated with a XOR algorithm.[54][55]

JPIN

A JPIN uses a encrypted and compressed payload that is disguised as a bitmap within the resource section of the installer.[56]

jRAT

jRAT’s Java payload is encrypted with AES.[57]

Kazuar

Kazuar is obfuscated using the open source ConfuserEx protector. Kazuar also obfuscates the name of created files/folders/mutexes and encrypts debug messages written to log files using the Rijndael cipher.[58]

Kwampirs

Kwampirs downloads additional files that are base64-encoded and encrypted with another cipher.[59]

Lazarus Group

Lazarus Group malware uses multiple types of encryption and encoding in its malware files, including AES, Caracachs, RC4, basic XOR with constant 0xA7, and other techniques.[60][61][62][63]

Leafminer

Leafminer obfuscated scripts that were used on victim machines.[64]

Leviathan

Leviathan has obfuscated code using base64 and gzip compression.[65]

Magic Hound

Magic Hound malware has used base64-encoded commands and files, and has also encrypted embedded strings with AES.[66]

Matroyshka

Matroyshka obfuscates API function names using a substitute cipher combined with Base64 encoding.[67]

menuPass

menuPass has encoded strings in its malware with base64 as well as with a simple, single-byte XOR obfuscation using key 0x40.[68][69]

Mosquito

Mosquito’s installer is obfuscated with a custom crypter to obfuscate the installer.[70]

MuddyWater

MuddyWater has used Daniel Bohannon’s Invoke-Obfuscation framework. The group also used files with base64 encoded PowerShell commands.[71][16][72]

NanHaiShu

NanHaiShu encodes files in Base64.[73]

OilRig

OilRig has encrypted and encoded data in its malware, including by using base64.[74][75][76]

OLDBAIT

OLDBAIT obfuscates internal strings and unpacks them at startup.[24]

OopsIE

OopsIE uses the Confuser protector to obfuscate an embedded .Net Framework assembly used for C2. OopsIE also encodes collected data in hexadecimal format before writing to files on disk and obfuscates strings.[77][78]

Orz

Some Orz strings are base64 encoded, such as the embedded DLL known as MockDll.[65]

Patchwork

Patchwork has obfuscated a script with Crypto Obfuscator.[79]

Pisloader

Pisloader obfuscates files by splitting strings into smaller sub-strings and including "garbage" strings that are never used. The malware also uses return-oriented programming (ROP) technique and single-byte XOR to obfuscate data.[80]

PoisonIvy

PoisonIvy hides any strings related to its own indicators of compromise.[81]

POSHSPY

POSHSPY appends a file signature header (randomly selected from six file types) to encrypted data prior to upload or download.[82]

PowerDuke

PowerDuke uses steganography to hide backdoors in PNG files, which are also encrypted using the Tiny Encryption Algorithm (TEA).[1]

PowerSploit

PowerSploit contains a collection of ScriptModification modules that compress and encode scripts and payloads.[83][84]

POWERSTATS

POWERSTATS uses character replacement, PowerShell environment variables, and XOR encoding to obfuscate code.[72]

Prikormka

Some resources in Prikormka are encrypted with a simple XOR operation or encoded with Base64.[85]

PUNCHTRACK

PUNCHTRACK is loaded and executed by a highly obfuscated launcher.[86]

Putter Panda

Droppers used by Putter Panda use RC4 or a 16-byte XOR key consisting of the bytes 0xA0 – 0xAF to obfuscate payloads.[87]

QUADAGENT

QUADAGENT was likely obfuscated using Invoke-Obfuscation.[75][16]

Reaver

Reaver encrypts some of its files with XOR.[88]

RedLeaves

A RedLeaves configuration file is encrypted with a simple XOR key, 0x53.[89]

Remsec

Some data in Remsec is encrypted using RC5 in CBC mode, AES-CBC with a hardcoded key, RC4, or Salsa20. Some data is also base64-encoded.[90][91]

RogueRobin

The PowerShell script with the RogueRobin payload was obfuscated using the COMPRESS technique in Invoke-Obfuscation.[92][16]

RTM

RTM strings, network data, configuration, and modules are encrypted with a modified RC4 algorithm.[93]

Sakula

Sakula uses single-byte XOR obfuscation to obfuscate many of its files.[94]

Shamoon

Shamoon contains base64-encoded strings.[95]

SHOTPUT

SHOTPUT is obscured using XOR encoding and appended to a valid GIF file.[96][97]

Smoke Loader

Smoke Loader uses a simple one-byte XOR method to obfuscate values in the malware.[98][99]

StreamEx

StreamEx obfuscates some commands by using statically programmed fragments of strings when starting a DLL. It also uses a one-byte xor against 0x91 to encode configuration data.[100]

SynAck

SynAck payloads are obfuscated prior to compilation to inhibit analysis and/or reverse engineering.[101][102]

Threat Group-3390

A Threat Group-3390 tool can encrypt payloads using XOR. Threat Group-3390 malware is also obfuscated using Metasploit’s shikata_ga_nai encoder as well as compressed with LZNT1 compression.[103][104]

TINYTYPHON

TINYTYPHON has used XOR with 0x90 to obfuscate its configuration file.[105]

TrickBot

TrickBot uses non-descriptive names to hide functionality and uses an AES CBC (256 bits) encryption algorithm for its loader and configuration files.[106]

TYPEFRAME

APIs and strings in some TYPEFRAME variants are RC4 encrypted. Another variant is encoded with XOR.[107]

USBStealer

Most strings in USBStealer are encrypted using 3DES and XOR and reversed.[108]

VERMIN

VERMIN is obfuscated using the obfuscation tool called ConfuserEx.[109]

Volgmer

A Volgmer variant is encoded using a simple XOR cipher.[110]

XTunnel

A version of XTunnel introduced in July 2015 obfuscated the binary using opaque predicates and other techniques in a likely attempt to obfuscate it and bypass security products.[111]

ZeroT

ZeroT has encrypted its payload with RC4.[112]

Mitigation

Ensure logging and detection mechanisms analyze commands after being processed/interpreted, rather than the raw input. Consider utilizing the Antimalware Scan Interface (AMSI) on Windows 10 for this functionality. [113]

Mitigation of compressed and encrypted files sent over the network and through email may not be advised since it may impact normal operations.

Detection

Detection of file obfuscation is difficult unless artifacts are left behind by the obfuscation process that are uniquely detectable with a signature. If detection of the obfuscation itself is not possible, it may be possible to detect the malicious activity that caused the obfuscated file (for example, the method that was used to write, read, or modify the file on the file system).

Flag and analyze commands containing indicators of obfuscation and known suspicious syntax such as uninterpreted escape characters like '''^''' and '''"'''. Windows' Sysmon and Event ID 4688 displays command-line arguments for processes. Deobfuscation tools can be used to detect these indicators in files/payloads. [114] [5] [115]

Obfuscation used in payloads for Initial Access can be detected at the network. Use network intrusion detection systems and email gateway filtering to identify compressed and encrypted attachments and scripts. Some email attachment detonation systems can open compressed and encrypted attachments. Payloads delivered over an encrypted connection from a website require encrypted network traffic inspection.

References

  1. Adair, S.. (2016, November 9). PowerDuke: Widespread Post-Election Spear Phishing Campaigns Targeting Think Tanks and NGOs. Retrieved January 11, 2017.
  2. Pierre-Marc Bureau. (2013, April 26). Linux/Cdorked.A: New Apache backdoor being used in the wild to serve Blackhole. Retrieved September 10, 2017.
  3. Tedesco, B. (2016, September 23). Security Alert Summary. Retrieved February 12, 2018.
  4. Bohannon, D. & Carr N. (2017, June 30). Obfuscation in the Wild: Targeted Attackers Lead the Way in Evasion Techniques. Retrieved February 12, 2018.
  5. Bohannon, D. & Holmes, L. (2017, July 27). Revoke-Obfuscation: PowerShell Obfuscation Detection Using Science. Retrieved February 12, 2018.
  6. White, J. (2017, March 10). Pulling Back the Curtains on EncodedCommand PowerShell Attacks. Retrieved February 12, 2018.
  7. Wikipedia. (2017, December 29). Duqu. Retrieved April 10, 2018.
  8. Saavedra-Morales, J., Sherstobitoff, R. (2018, January 6). Malicious Document Targets Pyeongchang Olympics. Retrieved April 10, 2018.
  9. Kaspersky Lab's Global Research and Analysis Team. (2015, December 4). Sofacy APT hits high profile targets with updated toolset. Retrieved December 10, 2015.
  10. Bitdefender. (2015, December). APT28 Under the Scope. Retrieved February 23, 2017.
  11. Ahl, I. (2017, June 06). Privileges and Credentials: Phished at the Request of Counsel. Retrieved May 17, 2018.
  12. Lee, B, et al. (2018, February 28). Sofacy Attacks Multiple Government Entities. Retrieved March 15, 2018.
  13. Lee, B., Falcone, R. (2018, June 06). Sofacy Group’s Parallel Attacks. Retrieved June 18, 2018.
  14. Symantec Security Response. (2016, September 6). Buckeye cyberespionage group shifts gaze from US to Hong Kong. Retrieved September 26, 2016.
  15. Carr, N.. (2017, May 14). Cyber Espionage is Alive and Well: APT32 and the Threat to Global Corporations. Retrieved June 18, 2017.
  16. Bohannon, D.. (2017, March 13). Invoke-Obfuscation - PowerShell Obfuscator. Retrieved June 18, 2017.
  17. Foltýn, T. (2018, March 13). OceanLotus ships new backdoor using old tricks. Retrieved May 22, 2018.
  18. Mercer, W., Rascagneres, P. (2018, January 16). Korea In The Crosshairs. Retrieved May 21, 2018.
  19. Hayashi, K., Ray, V. (2018, July 31). Bisonal Malware Used in Attacks Against Russia and South Korea. Retrieved August 7, 2018.
  20. Kaspersky Lab's Global Research & Analysis Team. (2017, October 16). BlackOasis APT and new targeted attacks leveraging zero-day exploit. Retrieved February 15, 2018.
  21. Bennett, J., Vengerik, B. (2017, June 12). Behind the CARBANAK Backdoor. Retrieved June 11, 2018.
  22. Svajcer, V. (2018, July 31). Multiple Cobalt Personality Disorder. Retrieved September 5, 2018.
  23. Grunzweig, J. (2018, January 31). Comnie Continues to Target Organizations in East Asia. Retrieved June 7, 2018.
  24. FireEye. (2015). APT28: A WINDOW INTO RUSSIA’S CYBER ESPIONAGE OPERATIONS?. Retrieved August 19, 2015.
  25. F-Secure Labs. (2015, April 22). CozyDuke: Malware Analysis. Retrieved December 10, 2015.
  26. Blaich, A., et al. (2018, January 18). Dark Caracal: Cyber-espionage at a Global Scale. Retrieved April 11, 2018.
  27. Chen, J. and Hsieh, M. (2017, November 7). REDBALDKNIGHT/BRONZE BUTLER’s Daserf Backdoor Now Using Steganography. Retrieved December 27, 2017.
  28. Gross, J. (2016, February 23). Operation Dust Storm. Retrieved September 19, 2017.
  29. ClearSky. (2016, January 7). Operation DustySky. Retrieved January 8, 2016.
  30. O'Gorman, G., and McDonald, G.. (2012, September 6). The Elderwood Project. Retrieved February 15, 2018.
  31. Falcone, R., et al.. (2015, June 16). Operation Lotus Blossom. Retrieved February 15, 2016.
  32. Falcone, R. and Miller-Osborn, J.. (2015, December 18). Attack on French Diplomat Linked to Operation Lotus Blossom. Retrieved February 15, 2016.
  33. Falcone, R. and Miller-Osborn, J.. (2016, February 3). Emissary Trojan Changelog: Did Operation Lotus Blossom Cause It to Evolve?. Retrieved February 15, 2016.
  34. Patil, S. (2018, June 26). Microsoft Office Vulnerabilities Used to Distribute FELIXROOT Backdoor in Recent Campaign. Retrieved July 31, 2018.
  35. Carr, N., et al. (2018, August 01). On the Hunt for FIN7: Pursuing an Enigmatic and Evasive Global Criminal Operation. Retrieved August 23, 2018.
  36. Elovitz, S. & Ahl, I. (2016, August 18). Know Your Enemy: New Financially-Motivated & Spear-Phishing Group. Retrieved February 26, 2018.
  37. FinFisher. (n.d.). Retrieved December 20, 2017.
  38. Allievi, A.,Flori, E. (2018, March 01). FinFisher exposed: A researcher’s tale of defeating traps, tricks, and complex virtual machines. Retrieved July 9, 2018.
  39. Patrick Wardle. (n.d.). Mac Malware of 2017. Retrieved September 21, 2018.
  40. Kaspersky Lab's Global Research & Analysis Team. (2017, August 30). Introducing WhiteBear. Retrieved September 21, 2017.
  41. Mercer, W., Rascagneres, P. (2018, April 26). GravityRAT - The Two-Year Evolution Of An APT Targeting India. Retrieved May 16, 2018.
  42. Scott-Railton, J., et al. (2016, August 2). Group5: Syria and the Iranian Connection. Retrieved September 26, 2016.
  43. Reynolds, J.. (2016, September 13). H1N1: Technical analysis reveals new capabilities. Retrieved September 26, 2016.
  44. Falcone, R. and Lee, B.. (2016, May 26). The OilRig Campaign: Attacks on Saudi Arabian Organizations Deliver Helminth Backdoor. Retrieved May 3, 2017.
  45. Fidelis Cybersecurity. (2015, December 16). Fidelis Threat Advisory #1020: Dissecting the Malware Involved in the INOCNATION Campaign. Retrieved March 24, 2016.
  46. FireEye. (2018, March 16). Suspected Chinese Cyber Espionage Group (TEMP.Periscope) Targeting U.S. Engineering and Maritime Industries. Retrieved April 11, 2018.
  47. Sherstobitoff, R. (2018, March 02). McAfee Uncovers Operation Honeybee, a Malicious Document Campaign Targeting Humanitarian Aid Groups. Retrieved May 16, 2018.
  48. Dell SecureWorks Counter Threat Unit Threat Intelligence. (2015, August 5). Threat Group-3390 Targets Organizations for Cyberespionage. Retrieved August 18, 2018.
  49. Symantec Security Response. (2010, January 18). The Trojan.Hydraq Incident. Retrieved February 20, 2018.
  50. ASERT Team. (2018, April 04). Innaput Actors Utilize Remote Access Trojan Since 2016, Presumably Targeting Victim Files. Retrieved July 9, 2018.
  51. Hromcová, Z. (2018, June 07). InvisiMole: Surprisingly equipped spyware, undercover since 2013. Retrieved July 10, 2018.
  52. Adams, B. (2017, December 17). Invoke-PSImage. Retrieved April 10, 2018.
  53. Falcone, R. and Lee, B. (2017, October 9). OilRig Group Steps Up Attacks with New Delivery Documents and New Injector Trojan. Retrieved January 8, 2018.
  54. F-Secure. (2015, September 8). Sofacy Recycles Carberp and Metasploit Code. Retrieved August 3, 2016.
  55. ESET. (2016, October). En Route with Sednit - Part 1: Approaching the Target. Retrieved November 8, 2016.
  56. Windows Defender Advanced Threat Hunting Team. (2016, April 29). PLATINUM: Targeted attacks in South and Southeast Asia. Retrieved February 15, 2018.
  57. Sharma, R. (2018, August 15). Revamped jRAT Uses New Anti-Parsing Techniques. Retrieved September 21, 2018.
  58. Levene, B, et al. (2017, May 03). Kazuar: Multiplatform Espionage Backdoor with API Access. Retrieved July 17, 2018.
  1. Moench, B. and Aboud, E. (2016, August 23). Trojan.Kwampirs. Retrieved May 10, 2018.
  2. Novetta Threat Research Group. (2016, February 24). Operation Blockbuster: Unraveling the Long Thread of the Sony Attack. Retrieved February 25, 2016.
  3. Novetta Threat Research Group. (2016, February 24). Operation Blockbuster: Loaders, Installers and Uninstallers Report. Retrieved March 2, 2016.
  4. Novetta Threat Research Group. (2016, February 24). Operation Blockbuster: Remote Administration Tools & Content Staging Malware Report. Retrieved March 16, 2016.
  5. Sherstobitoff, R. (2018, February 12). Lazarus Resurfaces, Targets Global Banks and Bitcoin Users. Retrieved February 19, 2018.
  6. Symantec Security Response. (2018, July 25). Leafminer: New Espionage Campaigns Targeting Middle Eastern Regions. Retrieved August 28, 2018.
  7. Axel F, Pierre T. (2017, October 16). Leviathan: Espionage actor spearphishes maritime and defense targets. Retrieved February 15, 2018.
  8. Lee, B. and Falcone, R. (2017, February 15). Magic Hound Campaign Attacks Saudi Targets. Retrieved December 27, 2017.
  9. Minerva Labs LTD and ClearSky Cyber Security. (2015, November 23). CopyKittens Attack Group. Retrieved September 11, 2017.
  10. Accenture Security. (2018, April 23). Hogfish Redleaves Campaign. Retrieved July 2, 2018.
  11. Matsuda, A., Muhammad I. (2018, September 13). APT10 Targeting Japanese Corporations Using Updated TTPs. Retrieved September 17, 2018.
  12. ESET, et al. (2018, January). Diplomats in Eastern Europe bitten by a Turla mosquito. Retrieved July 3, 2018.
  13. Lancaster, T.. (2017, November 14). Muddying the Water: Targeted Attacks in the Middle East. Retrieved March 15, 2018.
  14. Singh, S. et al.. (2018, March 13). Iranian Threat Group Updates Tactics, Techniques and Procedures in Spear Phishing Campaign. Retrieved April 11, 2018.
  15. F-Secure Labs. (2016, July). NANHAISHU RATing the South China Sea. Retrieved July 6, 2018.
  16. Sardiwal, M, et al. (2017, December 7). New Targeted Attack in the Middle East by APT34, a Suspected Iranian Threat Group, Using CVE-2017-11882 Exploit. Retrieved December 20, 2017.
  17. Lee, B., Falcone, R. (2018, July 25). OilRig Targets Technology Service Provider and Government Agency with QUADAGENT. Retrieved August 9, 2018.
  18. Unit 42. (2017, December 15). Unit 42 Playbook Viewer. Retrieved December 20, 2017.
  19. Lee, B., Falcone, R. (2018, February 23). OopsIE! OilRig Uses ThreeDollars to Deliver New Trojan. Retrieved July 16, 2018.
  20. Falcone, R., et al. (2018, September 04). OilRig Targets a Middle Eastern Government and Adds Evasion Techniques to OopsIE. Retrieved September 24, 2018.
  21. Lunghi, D., et al. (2017, December). Untangling the Patchwork Cyberespionage Group. Retrieved July 10, 2018.
  22. Grunzweig, J., et al. (2016, May 24). New Wekby Attacks Use DNS Requests As Command and Control Mechanism. Retrieved August 17, 2016.
  23. Hayashi, K. (2005, August 18). Backdoor.Darkmoon. Retrieved February 23, 2018.
  24. Dunwoody, M.. (2017, April 3). Dissecting One of APT29’s Fileless WMI and PowerShell Backdoors (POSHSPY). Retrieved April 5, 2017.
  25. PowerShellMafia. (2012, May 26). PowerSploit - A PowerShell Post-Exploitation Framework. Retrieved February 6, 2018.
  26. PowerSploit. (n.d.). PowerSploit. Retrieved February 6, 2018.
  27. Cherepanov, A.. (2016, May 17). Operation Groundbait: Analysis of a surveillance toolkit. Retrieved May 18, 2016.
  28. Kizhakkinan, D. et al.. (2016, May 11). Threat Actor Leverages Windows Zero-day Exploit in Payment Card Data Attacks. Retrieved February 12, 2018.
  29. Crowdstrike Global Intelligence Team. (2014, June 9). CrowdStrike Intelligence Report: Putter Panda. Retrieved January 22, 2016.
  30. Grunzweig, J. and Miller-Osborn, J. (2017, November 10). New Malware with Ties to SunOrcal Discovered. Retrieved November 16, 2017.
  31. PwC and BAE Systems. (2017, April). Operation Cloud Hopper: Technical Annex. Retrieved April 13, 2017.
  32. Symantec Security Response. (2016, August 8). Backdoor.Remsec indicators of compromise. Retrieved August 17, 2016.
  33. Kaspersky Lab's Global Research & Analysis Team. (2016, August 9). The ProjectSauron APT. Technical Analysis. Retrieved August 17, 2016.
  34. Falcone, R., et al. (2018, July 27). New Threat Actor Group DarkHydrus Targets Middle East Government. Retrieved August 2, 2018.
  35. Faou, M. and Boutin, J.. (2017, February). Read The Manual: A Guide to the RTM Banking Trojan. Retrieved March 9, 2017.
  36. Dell SecureWorks Counter Threat Unit Threat Intelligence. (2015, July 30). Sakula Malware Family. Retrieved January 26, 2016.
  37. Falcone, R.. (2016, November 30). Shamoon 2: Return of the Disttrack Wiper. Retrieved January 11, 2017.
  38. Eng, E., Caselden, D.. (2015, June 23). Operation Clandestine Wolf – Adobe Flash Zero-Day in APT3 Phishing Campaign. Retrieved January 14, 2016.
  39. Falcone, R. and Wartell, R.. (2015, July 27). Observations on CVE-2015-3113, Prior Zero-Days and the Pirpi Payload. Retrieved January 22, 2016.
  40. Hasherezade. (2016, September 12). Smoke Loader – downloader with a smokescreen still alive. Retrieved March 20, 2018.
  41. Baker, B., Unterbrink H. (2018, July 03). Smoking Guns - Smoke Loader learned new tricks. Retrieved July 5, 2018.
  42. Cylance SPEAR Team. (2017, February 9). Shell Crew Variants Continue to Fly Under Big AV’s Radar. Retrieved February 15, 2017.
  43. Ivanov, A. et al.. (2018, May 7). SynAck targeted ransomware uses the Doppelgänging technique. Retrieved May 22, 2018.
  44. Bettencourt, J. (2018, May 7). Kaspersky Lab finds new variant of SynAck ransomware using sophisticated Doppelgänging technique. Retrieved May 24, 2018.
  45. Pantazopoulos, N., Henry T. (2018, May 18). Emissary Panda – A potential new malicious tool. Retrieved June 25, 2018.
  46. Legezo, D. (2018, June 13). LuckyMouse hits national data center to organize country-level waterholing campaign. Retrieved August 18, 2018.
  47. Settle, A., et al. (2016, August 8). MONSOON - Analysis Of An APT Campaign. Retrieved September 22, 2016.
  48. Salinas, M., Holguin, J. (2017, June). Evolution of Trickbot. Retrieved July 31, 2018.
  49. US-CERT. (2018, June 14). MAR-10135536-12 – North Korean Trojan: TYPEFRAME. Retrieved July 13, 2018.
  50. Calvet, J. (2014, November 11). Sednit Espionage Group Attacking Air-Gapped Networks. Retrieved January 4, 2017.
  51. Lancaster, T., Cortes, J. (2018, January 29). VERMIN: Quasar RAT and Custom Malware Used In Ukraine. Retrieved July 5, 2018.
  52. US-CERT. (2017, November 01). Malware Analysis Report (MAR) - 10135536-D. Retrieved July 16, 2018.
  53. ESET. (2016, October). En Route with Sednit - Part 2: Observing the Comings and Goings. Retrieved November 21, 2016.
  54. Huss, D., et al. (2017, February 2). Oops, they did it again: APT Targets Russia and Belarus with ZeroT and PlugX. Retrieved April 5, 2018.
  55. Microsoft. (2015, June 9). Windows 10 to offer application developers new malware defenses. Retrieved February 12, 2018.
  56. Bohannon, D. (2017, July 27). Revoke-Obfuscation. Retrieved February 12, 2018.
  57. Carr, N. (2016, August 14). OfficeCrackros. Retrieved February 12, 2018.