Replication Through Removable Media
|Replication Through Removable Media|
|Tactic||Credential Access, Initial Access, Lateral Movement|
|System Requirements||Removable media allowed, Autorun enabled or vulnerability present that allows for code execution|
|Data Sources||File monitoring, Data loss prevention|
Adversaries may move onto systems, possibly those on disconnected or air-gapped networks, by copying malware to removable media and taking advantage of Autorun features when the media is inserted into a system and executes. In the case of Lateral Movement, this may occur through modification of executable files stored on removable media or by copying malware and renaming it to look like a legitimate file to trick users into executing it on a separate system. In the case of Initial Access, this may occur through manual manipulation of the media, modification of systems used to initially format the media, or modification to the media's firmware itself.
- APT28 uses a tool to infect connected USB devices and transmit itself to air-gapped computers when the infected USB device is inserted.1
- Darkhotel's selective infector modifies executables stored on removable media as a method of spreading across computers.2
- Agent.btz drops itself onto removable media devices and creates an autorun.inf file with an instruction to run that file. When the device is inserted into another system, it opens autorun.inf and loads the malware.3
- Part of APT28's operation involved using CHOPSTICK modules to copy itself to air-gapped machines and using files written to USB sticks to transfer data and command traffic.41
- DustySky searches for removable media and duplicates itself onto it.5
- Flame contains modules to infect USB sticks and spread laterally to other Windows systems the stick is plugged into using autorun functionality.6
- H1N1 has functionality to copy itself to removable media.7
- APT30 may have used the SHIPSHAPE malware to move onto air-gapped networks. SHIPSHAPE targets removable drives to spread to other systems by modifying the drive to use Autorun to execute or by hiding legitimate document files and copying an executable to the folder with the same name as the legitimate document.8
- USBStealer drops itself onto removable media and relies on Autorun to execute the malicious file when a user opens the removable media on another system.9
- Unknown Logger is capable of spreading to USB devices.10
Identify potentially malicious software that may be used to infect removable media or may result from tainted removable media, and audit and/or block it by using whitelisting13 tools, like AppLocker,1415 or Software Restriction Policies16 where appropriate.17
Monitor file access on removable media. Detect processes that execute from removable media after it is mounted or when initiated by a user. If a remote access tool is used in this manner to move laterally, then additional actions are likely to occur after execution, such as opening network connections for Command and Control and system and network information Discovery.
- Anthe, C. et al. (2015, October 19). Microsoft Security Intelligence Report Volume 19. Retrieved December 23, 2015.
- Kaspersky Lab's Global Research and Analysis Team. (2014, November). The Darkhotel APT A Story of Unusual Hospitality. Retrieved November 12, 2014.
- Shevchenko, S.. (2008, November 30). Agent.btz - A Threat That Hit Pentagon. Retrieved April 8, 2016.
- FireEye. (2015). APT28: A WINDOW INTO RUSSIA’S CYBER ESPIONAGE OPERATIONS?. Retrieved August 19, 2015.
- ClearSky. (2016, January 7). Operation DustySky. Retrieved January 8, 2016.
- Gostev, A. (2012, May 28). The Flame: Questions and Answers. Retrieved March 1, 2017.
- Reynolds, J.. (2016, September 14). H1N1: Technical analysis reveals new capabilities – part 2. Retrieved September 26, 2016.
- FireEye Labs. (2015, April). APT30 AND THE MECHANICS OF A LONG-RUNNING CYBER ESPIONAGE OPERATION. Retrieved May 1, 2015.
- Calvet, J. (2014, November 11). Sednit Espionage Group Attacking Air-Gapped Networks. Retrieved January 4, 2017.
- Settle, A., et al. (2016, August 8). MONSOON - Analysis Of An APT Campaign. Retrieved September 22, 2016.
- Microsoft. (n.d.). How to disable the Autorun functionality in Windows. Retrieved April 20, 2016.
- Microsoft. (2007, August 31). https://technet.microsoft.com/en-us/library/cc771759(v=ws.10).aspx. Retrieved April 20, 2016.
- Beechey, J. (2010, December). Application Whitelisting: Panacea or Propaganda?. Retrieved November 18, 2014.
- Tomonaga, S. (2016, January 26). Windows Commands Abused by Attackers. Retrieved February 2, 2016.
- NSA Information Assurance Directorate. (2014, August). Application Whitelisting Using Microsoft AppLocker. Retrieved March 31, 2016.
- Corio, C., & Sayana, D. P. (2008, June). Application Lockdown with Software Restriction Policies. Retrieved November 18, 2014.
- Microsoft. (2012, June 27). Using Software Restriction Policies and AppLocker Policies. Retrieved April 7, 2016.