Suspicious SUID Binary Execution (Auditd Sequence)

  1[metadata]
  2creation_date = "2026/05/08"
  3integration = ["auditd_manager"]
  4maturity = "production"
  5updated_date = "2026/05/08"
  6
  7[rule]
  8author = ["Elastic"]
  9description = """
 10Detects suspicious sequences where a non-root user launches a high-risk parent process (interpreter, shell one-liner, or
 11execution from user-writable paths) and then quickly executes a common privilege elevation helper (su, sudo, pkexec,
 12passwd, chsh, newgrp) that gains an effective UID of 0 while the real UID remains non-root. This can indicate misuse of
 13SUID/SGID helpers, polkit/sudo abuse, or interactive privilege escalation attempts captured via Auditd Manager telemetry.
 14"""
 15false_positives = [
 16    """
 17    Some break-glass workflows or automation may legitimately invoke sudo/su from scripts under user home directories.
 18    Validate the initiating user, parent context, and change approvals; tune by known admin tooling paths or accounts.
 19    """,
 20]
 21from = "now-9m"
 22index = ["auditbeat-*", "logs-auditd_manager.auditd-*"]
 23language = "eql"
 24license = "Elastic License v2"
 25name = "Suspicious SUID Binary Execution (Auditd Sequence)"
 26note = """## Triage and analysis
 27
 28### Investigating Suspicious SUID Binary Execution (Auditd Sequence)
 29
 30Confirm whether the non-root real user should be invoking su, sudo, pkexec, or account utilities as root. Review the
 31parent process chain and whether the parent executable location or shell invocation suggests a one-liner or staging
 32from user-writable paths.
 33
 34### Possible investigation steps
 35
 36- Review process details for script paths, temp directory execution, or suspicious interpreters.
 37- Check sudoers / polkit policy changes and recent authentication events for the user.
 38- Pivot for follow-on persistence (cron, systemd units) or credential access from the same session.
 39
 40### Response and remediation
 41
 42- If unauthorized, contain the session, revoke elevated access, and review sudoers and polkit configuration for tampering.
 43"""
 44references = [
 45    "https://attack.mitre.org/techniques/T1548/",
 46    "https://docs.elastic.co/integrations/auditd_manager",
 47]
 48risk_score = 47
 49rule_id = "50eba7ec-d3f0-474c-a7f4-0906b68e350f"
 50severity = "medium"
 51tags = [
 52    "Data Source: Auditd Manager",
 53    "Domain: Endpoint",
 54    "OS: Linux",
 55    "Use Case: Threat Detection",
 56    "Tactic: Privilege Escalation",
 57    "Resources: Investigation Guide",
 58]
 59timestamp_override = "event.ingested"
 60type = "eql"
 61query = '''
 62sequence by host.id with maxspan=30s
 63  [process where host.os.type == "linux" and event.type == "start" and
 64   event.action == "executed" and
 65   user.id != "0" and user.effective.id != "0" and
 66   (
 67     process.name like ("python*", "perl*", "ruby*", "php*", "lua*", ".*") or
 68     process.name in ("node", "bun", "java") or
 69     process.executable like ("/tmp/*", "/var/tmp/*", "/dev/shm/*", "/run/user/*", "/var/run/user/*", "/home/*/*") or
 70     (
 71       process.name in ("bash", "dash", "sh", "tcsh", "csh", "zsh", "ksh", "fish", "mksh") and
 72       process.args in ("-c", "--command", "-ic", "-ci", "-cl", "-lc")
 73     )
 74   )
 75  ] by process.pid
 76
 77  [process where host.os.type == "linux" and event.type == "start" and
 78   event.action == "executed" and
 79   user.effective.id == "0" and user.id != "0" and
 80   (
 81     (process.name in ("sudo", "pkexec") and
 82      not process.args like "-*" and
 83      not process.args : ("/usr/*", "/bin/*", "/sbin/*", "/opt/*")) or
 84     (process.name == "su" and
 85      not process.args in ("--command", "-c", "--shell", "-s")) or
 86     (process.name in ("passwd", "chsh", "newgrp") and
 87      not process.args in ("--shell", "-s", "--help"))
 88   )
 89  ] by process.parent.pid
 90'''
 91
 92[[rule.threat]]
 93framework = "MITRE ATT&CK"
 94
 95[[rule.threat.technique]]
 96id = "T1548"
 97name = "Abuse Elevation Control Mechanism"
 98reference = "https://attack.mitre.org/techniques/T1548/"
 99
100[[rule.threat.technique.subtechnique]]
101id = "T1548.001"
102name = "Setuid and Setgid"
103reference = "https://attack.mitre.org/techniques/T1548/001/"
104
105[[rule.threat.technique.subtechnique]]
106id = "T1548.003"
107name = "Sudo and Sudo Caching"
108reference = "https://attack.mitre.org/techniques/T1548/003/"
109
110[rule.threat.tactic]
111id = "TA0004"
112name = "Privilege Escalation"
113reference = "https://attack.mitre.org/tactics/TA0004/"