[rule]
description = """
Detects the creation of a DMG file in the temp directory. The creation of a DMG file like this has been observed being
used to exploit vulnerabilities that allow for mounting over sensitive parts of the filesystem, thereby bypassing
certain macOS security controls such as TCC and SIP. This activity is not normal or common and should be considered
suspicious.
"""
id = "fdb0e7ed-4210-4b71-be47-d0b0d9458fa7"
license = "Elastic License v2"
name = "Suspicious DMG File Creation in Tmp Directory"
os_list = ["macos"]
reference = [
"https://theevilbit.github.io/posts/cve-2021-30808/",
"https://www.trendmicro.com/en_us/research/22/l/diving-into-an-old-exploit-chain-and-discovering-3-new-sip-bypas.html",
]
version = "1.0.21"
query = '''
file where event.action in ("modification", "rename") and process.name == "diskimages-helper" and
file.extension == "dmg" and file.path like ("/private/tmp/*", "/tmp/*") and not
file.path like~ ("/private/tmp/munki-*/*.dmg", "/private/tmp/Ventura.dmg", "/private/tmp/Sonoma.dmg", "/private/tmp/com.ninxsoft.mist/*")
'''
min_endpoint_version = "8.11.0"
optional_actions = []
[[actions]]
action = "kill_process"
field = "process.entity_id"
state = 0
[[threat]]
framework = "MITRE ATT&CK"
[[threat.technique]]
id = "T1059"
name = "Command and Scripting Interpreter"
reference = "https://attack.mitre.org/techniques/T1059/"
[[threat.technique.subtechnique]]
id = "T1059.004"
name = "Unix Shell"
reference = "https://attack.mitre.org/techniques/T1059/004/"
[threat.tactic]
id = "TA0002"
name = "Execution"
reference = "https://attack.mitre.org/tactics/TA0002/"
[[threat]]
framework = "MITRE ATT&CK"
[[threat.technique]]
id = "T1211"
name = "Exploitation for Defense Evasion"
reference = "https://attack.mitre.org/techniques/T1211/"
[threat.tactic]
id = "TA0005"
name = "Defense Evasion"
reference = "https://attack.mitre.org/tactics/TA0005/"
[internal]
min_endpoint_version = "8.11.0"