T1001.001sub-technique of T1001 Data Obfuscation
Junk Data
ESXi · Linux · macOS · Windowsnothing on this site yetT1001.001 on attack.mitre.org
Adversaries may add junk data to protocols used for command and control to make detection more difficult. By adding random or meaningless data to the protocols used for command and control, adversaries can prevent trivial methods for decoding, deciphering, or otherwise analyzing the traffic. Examples may include appending/prepending data with junk characters or writing junk characters between significant characters.
how MITRE says to see it
Detecting Junk Data in C2 Channels via Behavioral Analysis
- Processes generating large outbound connections with disproportionate send/receive ratios, often to uncommon ports or hosts, potentially inserting meaningless data into protocol payloads.
- Outbound traffic with anomalous payload sizes and patterns from non-networking processes, often observed via packet inspection or connection logs.
- Previously unseen applications generating outbound connections with atypical data flow characteristics, such as excessive data with no return response.
- Anomalous traffic from ESXi host management daemons (like hostd or vpxa) embedding non-standard payloads in management protocols (e.g., HTTPS) or beaconing behavior.
what reduces it
- 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.