sigma-rules/rules/windows/execution_command_shell_started_by_unusual_process.toml

[metadata]
creation_date = "2020/08/21"
integration = ["endpoint", "windows"]
maturity = "production"
min_stack_comments = "New fields added: required_fields, related_integrations, setup"
min_stack_version = "8.3.0"
updated_date = "2024/03/28"

[rule]
author = ["Elastic"]
description = "Identifies a suspicious parent child process relationship with cmd.exe descending from an unusual process."
from = "now-9m"
index = ["winlogbeat-*", "logs-endpoint.events.process-*", "logs-windows.sysmon_operational-*", "endgame-*"]
language = "eql"
license = "Elastic License v2"
name = "Unusual Parent Process for cmd.exe"
risk_score = 47
rule_id = "3b47900d-e793-49e8-968f-c90dc3526aa1"
setup = """## Setup

If enabling an EQL rule on a non-elastic-agent index (such as beats) for versions <8.2,
events will not define `event.ingested` and default fallback for EQL rules was not added until version 8.2.
Hence for this rule to work effectively, users will need to add a custom ingest pipeline to populate
`event.ingested` to @timestamp.
For more details on adding a custom ingest pipeline refer - https://www.elastic.co/guide/en/fleet/current/data-streams-pipeline-tutorial.html
"""
severity = "medium"
tags = ["Domain: Endpoint", "OS: Windows", "Use Case: Threat Detection", "Tactic: Execution", "Data Source: Elastic Endgame", "Data Source: Elastic Defend", "Data Source: Sysmon"]
timestamp_override = "event.ingested"
type = "eql"

query = '''
process where host.os.type == "windows" and event.type == "start" and
  process.name : "cmd.exe" and
  process.parent.name : ("lsass.exe",
                         "csrss.exe",
                         "epad.exe",
                         "regsvr32.exe",
                         "dllhost.exe",
                         "LogonUI.exe",
                         "wermgr.exe",
                         "spoolsv.exe",
                         "jucheck.exe",
                         "jusched.exe",
                         "ctfmon.exe",
                         "taskhostw.exe",
                         "GoogleUpdate.exe",
                         "sppsvc.exe",
                         "sihost.exe",
                         "slui.exe",
                         "SIHClient.exe",
                         "SearchIndexer.exe",
                         "SearchProtocolHost.exe",
                         "FlashPlayerUpdateService.exe",
                         "WerFault.exe",
                         "WUDFHost.exe",
                         "unsecapp.exe",
                         "wlanext.exe" ) and
  not (process.parent.name : "dllhost.exe" and process.parent.args : "/Processid:{CA8C87C1-929D-45BA-94DB-EF8E6CB346AD}")
'''


[[rule.threat]]
framework = "MITRE ATT&CK"
[[rule.threat.technique]]
id = "T1059"
name = "Command and Scripting Interpreter"
reference = "https://attack.mitre.org/techniques/T1059/"


[rule.threat.tactic]
id = "TA0002"
name = "Execution"
reference = "https://attack.mitre.org/tactics/TA0002/"