Suspicious Loading of Malicious Netfilter Kernel Module for Traffic Signaling

ATT&CK techniques

Persistence → C2

Recon
Resource Dev
Initial Access
Execution
Persistence
- T1205.001Port Knocking
Priv Esc
Defense Evasion
- T1014Rootkit
- T1205.001Port Knocking
Cred Access
Discovery
Lateral Movement
Collection
C2
- T1205.001Port Knocking
Exfiltration
Impact

What it detects

This rule detects loading of a rogue netfilter kernel module used by the freenode Linux backdoor to implement magic-packet traffic signaling. Observed in NCC Group research analyzing the Linux backdoor from the freenode IRC network compromise which installs an ipt_ip_udp module hooking PREROUTING. Rogue kernel modules that enable covert wake-on-packet backdoors are a strong indicator of rootkit activity.

Reporting behind it

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Malicious Koske Userland Rootkit Installation via ld.so.preload (via file_event)

Suspicious Loading of Malicious Netfilter Kernel Module for Traffic Signaling

Pivot detection · T1014 · 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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