sigma-rules/rules_building_block/execution_unsigned_service_executable.toml

[metadata]
bypass_bbr_timing = true
creation_date = "2023/07/14"
integration = ["endpoint"]
maturity = "production"
updated_date = "2026/02/19"

[rule]
author = ["Elastic"]
building_block_type = "default"
description = """
This rule identifies the execution of unsigned executables via service control manager (SCM). Adversaries may abuse SCM
to execute malware or escalate privileges.
"""
from = "now-9m"
index = ["logs-endpoint.events.process-*"]
language = "kuery"
license = "Elastic License v2"
name = "Execution of an Unsigned Service"
risk_score = 21
rule_id = "56fdfcf1-ca7c-4fd9-951d-e215ee26e404"
severity = "low"
tags = [
    "Domain: Endpoint",
    "OS: Windows",
    "Use Case: Threat Detection",
    "Tactic: Execution",
    "Tactic: Defense Evasion",
    "Rule Type: BBR",
    "Data Source: Elastic Defend",
]
timestamp_override = "event.ingested"
type = "new_terms"

query = '''
host.os.type:windows and event.category:process and event.type:start and 
process.parent.executable:"C:\\Windows\\System32\\services.exe" and 
(process.code_signature.exists:false or process.code_signature.trusted:false) and
not process.code_signature.status : (errorCode_endpoint* or "errorChaining")
'''


[[rule.threat]]
framework = "MITRE ATT&CK"
[[rule.threat.technique]]
id = "T1569"
name = "System Services"
reference = "https://attack.mitre.org/techniques/T1569/"
[[rule.threat.technique.subtechnique]]
id = "T1569.002"
name = "Service Execution"
reference = "https://attack.mitre.org/techniques/T1569/002/"



[rule.threat.tactic]
id = "TA0002"
name = "Execution"
reference = "https://attack.mitre.org/tactics/TA0002/"
[[rule.threat]]
framework = "MITRE ATT&CK"
[[rule.threat.technique]]
id = "T1036"
name = "Masquerading"
reference = "https://attack.mitre.org/techniques/T1036/"
[[rule.threat.technique.subtechnique]]
id = "T1036.001"
name = "Invalid Code Signature"
reference = "https://attack.mitre.org/techniques/T1036/001/"



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

[rule.new_terms]
field = "new_terms_fields"
value = ["host.id", "process.executable", "user.id"]
[[rule.new_terms.history_window_start]]
field = "history_window_start"
value = "now-5d"