Binary Executed from Shared Memory Directory

Elastic Stack Serverless Security

Identifies the execution of a binary by root in Linux shared memory directories: (/dev/shm/, /run/shm/, /var/run/, /var/lock/). This activity is to be considered highly abnormal and should be investigated. Threat actors have placed executables used for persistence on high-uptime servers in these directories as system backdoors.

Rule type: eql

Rule indices:

• logs-endpoint.events.*

Severity: high

Risk score: 73

Runs every: 5m

Searches indices from: now-9m (https://www.elastic.co/guide/en/elasticsearch/reference/current/common-options.html#date-math[Date Math format], see also Additional look-back time)

Maximum alerts per execution: 100

References:

• https://linuxsecurity.com/features/fileless-malware-on-linux
• https://twitter.com/GossiTheDog/status/1522964028284411907
• https://www.elastic.co/security-labs/a-peek-behind-the-bpfdoor

Tags:

• Elastic
• Host
• Linux
• Threat Detection
• Execution
• BPFDoor

Version: 101

Rule authors:

• Elastic

Rule license: Elastic License v2

process where event.type == "start" and
    event.action == "exec" and user.name == "root" and
    process.executable : (
        "/dev/shm/*",
        "/run/shm/*",
        "/var/run/*",
        "/var/lock/*"
    ) and
    not process.executable : ( "/var/run/docker/*")

Framework: MITRE ATT&CKTM

• Tactic:

  • Name: Execution
  • ID: TA0002
  • Reference URL: https://attack.mitre.org/tactics/TA0002/

• Technique:

  • Name: Command and Scripting Interpreter
  • ID: T1059
  • Reference URL: https://attack.mitre.org/techniques/T1059/