Suspicious Execution - Short Program Name

Elastic Stack Serverless Security

Identifies process execution with a single character process name. This is often done by adversaries while staging or executing temporary utilities.

Rule type: eql

Rule indices:

• winlogbeat-*
• logs-endpoint.events.*
• logs-windows.*

Severity: medium

Risk score: 47

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: None

Tags:

• Elastic
• Host
• Windows
• Threat Detection
• Defense Evasion

Version: 6

Rule authors:

• Elastic

Rule license: Elastic License v2

process where event.type in ("start", "process_started") and length(process.name) > 0 and
 length(process.name) == 5 and host.os.name == "Windows" and length(process.pe.original_file_name) > 5

Framework: MITRE ATT&CKTM

• Tactic:

  • Name: Defense Evasion
  • ID: TA0005
  • Reference URL: https://attack.mitre.org/tactics/TA0005/

• Technique:

  • Name: Masquerading
  • ID: T1036
  • Reference URL: https://attack.mitre.org/techniques/T1036/

• Sub-technique:

  • Name: Rename System Utilities
  • ID: T1036.003
  • Reference URL: https://attack.mitre.org/techniques/T1036/003/