Exfiltration Over Command and Control Channel

Data exfiltration is performed over the Command and Control channel. Data is encoded into the normal communications channel using the same protocol as command and control communications.

ID: T1041

Tactic: Exfiltration

Platform:  Linux, macOS, Windows

Data Sources:  User interface, Process monitoring

Requires Network:  Yes

Version: 1.0

Examples

NameDescription
ADVSTORESHELL

ADVSTORESHELL exfiltrates data over the same channel used for C2.[1]

APT3

APT3 has a tool that exfiltrates data over the C2 channel.[2]

APT32

APT32's backdoor has exfiltrated data using the already opened channel with its C&C server.[3]

Astaroth

Astaroth exfiltrates collected information from its r1.log file to the external C2 server.[4]

BACKSPACE

Adversaries can direct BACKSPACE to upload files to the C2 Server.[5]

Bankshot

Bankshot exfiltrates data over its C2 channel.[6]

CallMe

CallMe exfiltrates data to its C2 server over the same protocol as C2 communications.[7]

Cannon

Cannon exfiltrates collected data over email via SMTP/S and POP3/S C2 channels.[8]

Emotet

Emotet has been seen exfiltrating system information stored within cookies sent within an HTTP GET request back to its C2 servers.[9]

Empire

Empire can send data gathered from a target through the command and control channel.[10]

Gamaredon Group

A Gamaredon Group file stealer transfers collected files to a hardcoded C2 server.[11]

HOPLIGHT

HOPLIGHT has used its C2 channel to exfiltrate data. [12]

Ke3chang

Ke3chang transferred compressed and encrypted RAR files containing exfiltration through the established backdoor command and control channel during operations.[13]

Lazarus Group

Lazarus Group malware IndiaIndia saves information gathered about the victim to a file that is uploaded to one of its 10 C2 servers. Another Lazarus Group malware sample also performs exfiltration over the C2 channel.[14][15][16]

MobileOrder

MobileOrder exfiltrates data to its C2 server over the same protocol as C2 communications.[7]

NETEAGLE

NETEAGLE is capable of reading files over the C2 channel.[5]

OopsIE

OopsIE can upload files from the victim's machine to its C2 server.[17]

Proxysvc

Proxysvc performs data exfiltration over the control server channel using a custom protocol.[18]

Psylo

Psylo exfiltrates data to its C2 server over the same protocol as C2 communications.[7]

Pteranodon

Pteranodon exfiltrates screenshot files to its C2 server.[11]

Pupy

Pupy can send screenshots files, keylogger data, files, and recorded audio back to the C2 server.[19]

Remexi

Remexi performs exfiltration over BITSAdmin, which is also used for the C2 channel.[20]

ROKRAT

ROKRAT sends collected files back over same C2 channel.[21]

Stealth Falcon

After data is collected by Stealth Falcon malware, it is exfiltrated over the existing C2 channel.[22]

Mitigation

Mitigations for command and control apply. Network intrusion detection and prevention systems that use network signatures to identify traffic for specific adversary malware can be used to mitigate activity at the network level. Signatures are often for unique indicators within protocols and may be based on the specific obfuscation technique used by a particular adversary or tool, and will likely be different across various malware families and versions. Adversaries will likely change tool command and control signatures over time or construct protocols in such a way to avoid detection by common defensive tools. [23]

Detection

Detection for command and control applies. Analyze network data for uncommon data flows (e.g., a client sending significantly more data than it receives from a server). Processes utilizing the network that do not normally have network communication or have never been seen before are suspicious. Analyze packet contents to detect communications that do not follow the expected protocol behavior for the port that is being used. [23]

References

  1. ESET. (2016, October). En Route with Sednit - Part 2: Observing the Comings and Goings. Retrieved November 21, 2016.
  2. Chen, X., Scott, M., Caselden, D.. (2014, April 26). New Zero-Day Exploit targeting Internet Explorer Versions 9 through 11 Identified in Targeted Attacks. Retrieved January 14, 2016.
  3. Dumont, R. (2019, March 20). Fake or Fake: Keeping up with OceanLotus decoys. Retrieved April 1, 2019.
  4. Salem, E. (2019, February 13). ASTAROTH MALWARE USES LEGITIMATE OS AND ANTIVIRUS PROCESSES TO STEAL PASSWORDS AND PERSONAL DATA. Retrieved April 17, 2019.
  5. FireEye Labs. (2015, April). APT30 AND THE MECHANICS OF A LONG-RUNNING CYBER ESPIONAGE OPERATION. Retrieved May 1, 2015.
  6. Sherstobitoff, R. (2018, March 08). Hidden Cobra Targets Turkish Financial Sector With New Bankshot Implant. Retrieved May 18, 2018.
  7. Falcone, R. and Miller-Osborn, J.. (2016, January 24). Scarlet Mimic: Years-Long Espionage Campaign Targets Minority Activists. Retrieved February 10, 2016.
  8. Falcone, R., Lee, B. (2018, November 20). Sofacy Continues Global Attacks and Wheels Out New ‘Cannon’ Trojan. Retrieved November 26, 2018.
  9. Trend Micro. (2019, January 16). Exploring Emotet's Activities . Retrieved March 25, 2019.
  10. Schroeder, W., Warner, J., Nelson, M. (n.d.). Github PowerShellEmpire. Retrieved April 28, 2016.
  11. Kasza, A. and Reichel, D.. (2017, February 27). The Gamaredon Group Toolset Evolution. Retrieved March 1, 2017.
  12. US-CERT. (2019, April 10). MAR-10135536-8 – North Korean Trojan: HOPLIGHT. Retrieved April 19, 2019.