Malicious Encrypted Reverse Shell via Netcat and GPG on Linux

ATT&CK techniques

Execution → C2

Recon
Resource Dev
Initial Access
Execution
- T1059.004Unix Shell
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
- T1071.001Web Protocols
Exfiltration
Impact

What it detects

This rule detects a command pipeline that reads from a netcat listener decrypts the traffic with gpg and pipes it into a shell which the opportunistic Log4j campaign uses to run an encrypted reverse shell that evades network content inspection.

Reporting behind it

Related detections9 linkedT1071.001 — drag to rearrange

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Suspicious Cobalt Strike Malleable Profile Beaconing via Legacy MSIE9 User-Agent and IE Compatibility URIs (via proxy)

Malicious Cobalt Strike Default Named Pipe Activity

Malicious VoidLink Kernel Rootkit C2 Endpoints via HTTP (via proxy)

Malicious Encrypted Reverse Shell via Netcat and GPG on Linux

Pivot detection · T1071.001 · 9 related

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.

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