Data Obfuscation

Adversaries may obfuscate command and control traffic to make it more difficult to detect. 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: T1001
Sub-techniques:  T1001.001, T1001.002, T1001.003
Tactic: Command And Control
Platforms: Linux, Windows, macOS
Data Sources: Network protocol analysis, Packet capture, Process monitoring, Process use of network
Requires Network:  Yes
Version: 1.1
Created: 31 May 2017
Last Modified: 15 March 2020

Procedure Examples

Name Description
Axiom

The Axiom group has used other forms of obfuscation, include commingling legitimate traffic with communications traffic so that network streams appear legitimate.

FlawedAmmyy

FlawedAmmyy may obfuscate portions of the initial C2 handshake.[1]

Mitigations

Mitigation Description
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.

Detection

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. [2]

References