Detection rules › Elastic

Renamed AutoIt Scripts Interpreter

Source
github.com/elastic/protections-artifacts

Identifies suspicious AutoIT process execution events. Attackers may rename an AutoIT executable file in an attempt to avoid signature-based detection.

MITRE ATT&CK coverage

Rule body

[rule]
description = """
Identifies suspicious AutoIT process execution events. Attackers may rename an AutoIT executable file in an attempt to
avoid signature-based detection.
"""
id = "99f2327e-871f-4b8a-ae75-d1c4697aefe4"
license = "Elastic License v2"
name = "Renamed AutoIt Scripts Interpreter"
os_list = ["windows"]
version = "1.0.32"

query = '''
process where event.action == "start" and
  process.pe.original_file_name : "AutoIt*.exe" and not process.name : "AutoIt*.exe" and 
  not process.executable : "?:\\Program Files (x86)\\AutoIt3\\AutoIt3.exe"
'''

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

[[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 : "AutoIt*.exe" and not process.name : "AutoIt*.exe" and 
  not process.executable : "?:\\Program Files (x86)\\AutoIt3\\AutoIt3.exe"

Exclusions

The rule actively suppresses these predicates.

FieldKindExcluded valuesSearch
process.executableeq?:\Program Files (x86)\AutoIt3\AutoIt3.exeexcludes:process.executable field:"process.executable" value:"?:\Program Files (x86)\AutoIt3\AutoIt3.exe"
process.namewildcardAutoIt*.exeexcludes:process.name field:"process.name" value:"AutoIt*.exe"

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
event.actioneq
  • start corpus 391 (elastic 391)
field:"EventType" kind:eq value:"start"
process.pe.original_file_namewildcard
  • AutoIt*.exe corpus 8 (elastic 8)
field:"OriginalFileName" kind:wildcard value:"AutoIt*.exe"