Detection rules › Elastic

Renamed Third Party Administrator Tools

Source
github.com/elastic/protections-artifacts

Identifies third party administrative tools commonly used by adversaries but running with unexpected file names.

MITRE ATT&CK coverage

Rule body

[rule]
description = "Identifies third party administrative tools commonly used by adversaries but running with unexpected file names."
id = "b707de5c-8e4d-4d2c-be22-b09a7e82b73f"
license = "Elastic License v2"
name = "Renamed Third Party Administrator Tools"
os_list = ["windows"]
version = "1.0.33"

query = '''
process where event.action == "start" and
  (
   (process.pe.original_file_name : "procdump" and 
    process.code_signature.subject_name == "Microsoft Corporation" and not process.name : "*procdump*.exe") or
   (process.pe.original_file_name : "psexec.c" and process.code_signature.subject_name == "Microsoft Corporation" and not process.name : "*psexec*.exe") or
   (process.pe.original_file_name : "sdelete.exe" and process.code_signature.subject_name == "Microsoft Corporation" and not process.name : "*sdelete*")
  ) and
  not process.executable :
    ("?:\\Windows\\System32\\*.exe", 
	 "?:\\Windows\\SysWOW64\\*.exe", 
	 "?:\\Program Files (x86)\\*.exe", 
	 "?:\\Program Files\\*.exe")
'''

min_endpoint_version = "7.15.0"
[[actions]]
action = "kill_process"
field = "process.entity_id"
state = 0

[[optional_actions]]
action = "rollback"
field = "process.entity_id"
state = 0

[[threat]]
framework = "MITRE ATT&CK"
[[threat.technique]]
id = "T1036"
name = "Masquerading"
reference = "https://attack.mitre.org/techniques/T1036/"
[[threat.technique.subtechnique]]
id = "T1036.003"
name = "Rename Legitimate Utilities"
reference = "https://attack.mitre.org/techniques/T1036/003/"



[threat.tactic]
id = "TA0005"
name = "Defense Evasion"
reference = "https://attack.mitre.org/tactics/TA0005/"

[internal]
min_endpoint_version = "7.15.0"

Stages and Predicates

Stage 1: process

process where event.action == "start" and
  (
   (process.pe.original_file_name : "procdump" and 
    process.code_signature.subject_name == "Microsoft Corporation" and not process.name : "*procdump*.exe") or
   (process.pe.original_file_name : "psexec.c" and process.code_signature.subject_name == "Microsoft Corporation" and not process.name : "*psexec*.exe") or
   (process.pe.original_file_name : "sdelete.exe" and process.code_signature.subject_name == "Microsoft Corporation" and not process.name : "*sdelete*")
  ) and
  not process.executable :
    ("?:\\Windows\\System32\\*.exe", 
	 "?:\\Windows\\SysWOW64\\*.exe", 
	 "?:\\Program Files (x86)\\*.exe", 
	 "?:\\Program Files\\*.exe")

Exclusions

The rule actively suppresses these predicates.

FieldKindExcluded valuesSearch
process.executablewildcard?:\Windows\System32\*.exe, ?:\Windows\SysWOW64\*.exe, ?:\Program Files (x86)\*.exe, ?:\Program Files\*.exeexcludes:process.executable

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
event.actioneq
  • start corpus 391 (elastic 391)
field:"EventType" kind:eq value:"start"
process.code_signature.subject_nameeq
  • Microsoft Corporation corpus 2 (elastic 2)
field:"Signature" kind:eq value:"Microsoft Corporation"
process.pe.original_file_namewildcard
  • procdump corpus 6 (elastic 3, sigma 2, splunk 1)
  • psexec.c corpus 7 (elastic 3, sigma 2, splunk 2)
  • sdelete.exe corpus 4 (sigma 2, elastic 1, splunk 1)
field:"OriginalFileName" kind:wildcard