Modification of OpenSSH Binaries

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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.*
  • endgame-*

Severity: medium

Risk score: 47

Runs every: 5m

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

Maximum alerts per execution: 100

References:

Tags:

  • Domain: Endpoint
  • OS: Linux
  • Use Case: Threat Detection
  • Tactic: Credential Access
  • Tactic: Persistence
  • Tactic: Lateral Movement
  • Data Source: Elastic Endgame
  • Data Source: Elastic Defend

Version: 107

Rule authors:

  • Elastic

Rule license: Elastic License v2

Rule query

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event.category:file and host.os.type:linux and event.type:change and
  process.name:(* and not (dnf or dnf-automatic or dpkg or yum or rpm or yum-cron or anacron)) and
  (file.path:(/usr/bin/scp or
                /usr/bin/sftp or
                /usr/bin/ssh or
                /usr/sbin/sshd) or
  file.name:libkeyutils.so) and
  not process.executable:/usr/share/elasticsearch/*

Framework: MITRE ATT&CKTM