Modification of OpenSSH Binariesedit

Adversaries may modify SSH related binaries for persistence or credential access by patching sensitive functions to enable unauthorized access or by logging SSH credentials for exfiltration.

Rule type: query

Rule indices:

  • auditbeat-*
  • logs-endpoint.events.*

Severity: medium

Risk score: 47

Runs every: 5 minutes

Searches indices from: now-9m (Date Math format, see also Additional look-back time)

Maximum alerts per execution: 100

References:

Tags:

  • Elastic
  • Host
  • Linux
  • Threat Detection
  • Credential Access
  • Persistence

Version: 1

Added (Elastic Stack release): 7.12.0

Rule authors: Elastic

Rule license: Elastic License v2

Potential false positivesedit

Trusted OpenSSH executable updates. It’s recommended to verify the integrity of OpenSSH binary changes.

Rule queryedit

event.category:file and event.type:change and process.name:* and
(file.path:(/usr/sbin/sshd or /usr/bin/ssh or /usr/bin/sftp or
/usr/bin/scp) or file.name:libkeyutils.so) and not
process.executable:/usr/bin/dpkg

Threat mappingedit

Framework: MITRE ATT&CKTM