Suspicious PAM Backdoor via pam_exec Configuration Change
- Product
- linux
- Category
- process_creation
- Author
- HuntRule
- Published
- 2026-05-11
- Updated
- 2026-08-28
ATT&CK techniques
Persistence → Cred AccessRecon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact
What it detects
This rule detects modification of a PAM configuration file to load pam_exec.so, a pluggable authentication module backdoor described in Elastic Linux persistence research. By adding a pam_exec directive to an sshd PAM stack the attacker runs an arbitrary script on each authentication for persistence and credential capture. Edits to files under /etc/pam.d that introduce pam_exec are highly suspicious.
Reporting behind it
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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