Adversaries may obfuscate command and control traffic to make it more difficult to detect.[1] Command and control (C2) communications are hidden (but not necessarily encrypted) in an attempt to make the content more difficult to discover or decipher and to make the communication less conspicuous and hide commands from being seen. This encompasses many methods, such as adding junk data to protocol traffic, using steganography, or impersonating legitimate protocols.
| ID | Name | Description |
|---|---|---|
| S1111 | DarkGate |
DarkGate will retrieved encrypted commands from its command and control server for follow-on actions such as cryptocurrency mining.[2] |
| S0381 | FlawedAmmyy |
FlawedAmmyy may obfuscate portions of the initial C2 handshake.[3] |
| S1120 | FRAMESTING |
FRAMESTING can send and receive zlib compressed data within |
| S1044 | FunnyDream |
FunnyDream can send compressed and obfuscated packets to C2.[1] |
| G0047 | Gamaredon Group |
Gamaredon Group has used obfuscated VBScripts with randomly generated variable names and concatenated strings.[5] |
| S1100 | Ninja |
Ninja has the ability to modify headers and URL paths to hide malicious traffic in HTTP requests.[6] |
| S0439 | Okrum |
Okrum leverages the HTTP protocol for C2 communication, while hiding the actual messages in the Cookie and Set-Cookie headers of the HTTP requests.[7] |
| C0014 | Operation Wocao |
During Operation Wocao, threat actors encrypted IP addresses used for "Agent" proxy hops with RC4.[8] |
| S0495 | RDAT |
RDAT has used encoded data within subdomains as AES ciphertext to communicate from the host to the C2.[9] |
| S0610 | SideTwist |
SideTwist can embed C2 responses in the source code of a fake Flickr webpage.[10] |
| S0533 | SLOTHFULMEDIA |
SLOTHFULMEDIA has hashed a string containing system information prior to exfiltration via POST requests.[11] |
| S0682 | TrailBlazer |
TrailBlazer can masquerade its C2 traffic as legitimate Google Notifications HTTP requests.[12] |
| ID | Mitigation | Description |
|---|---|---|
| M1031 | Network Intrusion Prevention |
Network intrusion detection and prevention systems that use network signatures to identify traffic for specific adversary malware can be used to mitigate some obfuscation activity at the network level. |
| ID | Data Source | Data Component | Detects |
|---|---|---|---|
| DS0029 | Network Traffic | Network Traffic Content |
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. [13] |