persistence_screensaver_engine_unexpected_child_process.toml

[metadata]
creation_date = "2021/10/05"
maturity = "production"
updated_date = "2022/03/31"

[rule]
author = ["Elastic"]
description = """
Identifies when a child process is spawned by the screensaver engine process, which is consistent with an attacker's
malicious payload being executed after the screensaver activated on the endpoint. An adversary can maintain persistence
on a macOS endpoint by creating a malicious screensaver (.saver) file and configuring the screensaver plist file to
execute code each time the screensaver is activated.
"""
from = "now-9m"
index = ["auditbeat-*", "logs-endpoint.events.*"]
language = "eql"
license = "Elastic License v2"
name = "Unexpected Child Process of macOS Screensaver Engine"
note = """## Triage and analysis

- Analyze the descendant processes of the ScreenSaverEngine process for malicious code and suspicious behavior such
as a download of a payload from a server.
- Review the installed and activated screensaver on the host. Triage the screensaver (.saver) file that was triggered to
identify whether the file is malicious or not.


## Config

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 8.2, so you will need to add a custom pipeline to populate `event.ingested` to @timestamp for this rule to work.
"""
references = [
    "https://posts.specterops.io/saving-your-access-d562bf5bf90b",
    "https://github.com/D00MFist/PersistentJXA",
]
risk_score = 47
rule_id = "48d7f54d-c29e-4430-93a9-9db6b5892270"
severity = "medium"
tags = ["Elastic", "Host", "macOS", "Threat Detection", "Persistence"]
timestamp_override = "event.ingested"
type = "eql"

query = '''
process where event.type == "start" and process.parent.name == "ScreenSaverEngine"
'''


[[rule.threat]]
framework = "MITRE ATT&CK"
[[rule.threat.technique]]
id = "T1546"
name = "Event Triggered Execution"
reference = "https://attack.mitre.org/techniques/T1546/"


[rule.threat.tactic]
id = "TA0003"
name = "Persistence"
reference = "https://attack.mitre.org/tactics/TA0003/"