SUID/SGID Bit Set

edit

An adversary may add the setuid or setgid bit to a file or directory in order to run a file with the privileges of the owning user or group. An adversary can take advantage of this to either do a shell escape or exploit a vulnerability in an application with the setuid or setgid bit to get code running in a different user’s context. Additionally, adversaries can use this mechanism on their own malware to make sure they’re able to execute in elevated contexts in the future.

Rule type: eql

Rule indices:

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

Severity: low

Risk score: 21

Runs every: 5m

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

Maximum alerts per execution: 33

References: None

Tags:

  • Domain: Endpoint
  • OS: Linux
  • OS: macOS
  • Use Case: Threat Detection
  • Tactic: Privilege Escalation
  • Data Source: Elastic Defend

Version: 104

Rule authors:

  • Elastic

Rule license: Elastic License v2

Rule query

edit
process where host.os.type == "linux" and event.type == "start" and event.action == "exec" and (
  (process.name == "chmod" and (process.args : ("+s", "u+s", "g+s") or process.args regex "[24][0-9]{3}")) or
  (process.name == "install" and process.args : "-m" and
  (process.args : ("+s", "u+s", "g+s") or process.args regex "[24][0-9]{3}"))
) and not (
  process.parent.executable : (
    "/usr/NX/*", "/var/lib/docker/*", "/var/lib/dpkg/info*", "/tmp/newroot/*",
    "/System/Library/PrivateFrameworks/PackageKit.framework/Versions/A/XPCServices/package_script_service.xpc/Contents/MacOS/package_script_service"
  ) or
  process.args : (
    "/run/*", "/var/run/*", "/usr/bin/keybase-redirector", "/usr/local/share/fonts", "/usr/bin/ssh-agent"
  )
)

Framework: MITRE ATT&CKTM