Memory Dump File with Unusual Extension

Identifies the creation of a memory dump file with an unusual extension, which can indicate an attempt to disguise a memory dump as another file type to bypass security defenses.

Rule type: eql
Rule indices:

• logs-endpoint.events.file-*

Rule Severity: low
Risk Score: 21
Runs every:
Searches indices from: now-9m
Maximum alerts per execution: ?
References:

Tags:

• Domain: Endpoint
• OS: Windows
• Use Case: Threat Detection
• Tactic: Credential Access
• Tactic: Defense Evasion
• Data Source: Elastic Defend
• Rule Type: BBR

Version: ?
Rule authors:

• Elastic

Rule license: Elastic License v2

file where host.os.type == "windows" and event.type == "creation" and

  /* MDMP header */
  file.Ext.header_bytes : "4d444d50*" and
  not file.extension : ("dmp", "mdmp", "hdmp", "edmp", "full", "tdref", "cg", "tmp", "dat") and
  not
  (
    process.executable : "?:\\Program Files\\Endgame\\esensor.exe" and
    process.code_signature.trusted == true and length(file.extension) == 0
  ) and
  not
  (
    process.name : "System" and file.extension : "tmpscan"
  )

Framework: MITRE ATT&CK

• Tactic:

  • Name: Credential Access
  • Id: TA0006
  • Reference URL: https://attack.mitre.org/tactics/TA0006/

• Technique:

  • Name: OS Credential Dumping
  • Id: T1003
  • Reference URL: https://attack.mitre.org/techniques/T1003/

• Sub Technique:

  • Name: LSASS Memory
  • Id: T1003.001
  • Reference URL: https://attack.mitre.org/techniques/T1003/001/

Framework: MITRE ATT&CK

• 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: Masquerade File Type
  • Id: T1036.008
  • Reference URL: https://attack.mitre.org/techniques/T1036/008/