1200KM / sigma-rule
Payload Decoded and Decrypted via Built-in Utilities — Sigma Rule
Sigma rule 234dc5df-40b5-49d1-bf53-0d44ce778eca. Payload Decoded and Decrypted via Built-in Utilities — Sigma Rule. Detects when a built-in utility is used to decode and decrypt a payload after a macOS disk image (DMG) is executed. Malware authors may attempt to evade detection and trick users into executing malicious code by encoding and encrypting their payload and placing it in a disk image file. This behavior is consistent with adware or malware families such as Bundlore and Shlayer.
Rule metadata and linked tags
Author: Tim Rauch (rule), Elastic (idea). Source status: test; severity: medium. Source dates: 2022-10-17 / not supplied.
{
"category": "process_creation",
"product": "macos"
}Pinned original Sigma rule · Detection Rule License 1.1
Source SHA-256: 047c0927959706f41393a197878e3fd8c38d1dbe6b2abd9ca0088cb47b7c2645
Detection logic
Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.
title: Payload Decoded and Decrypted via Built-in Utilities
id: 234dc5df-40b5-49d1-bf53-0d44ce778eca
status: test
description: Detects when a built-in utility is used to decode and decrypt a payload after a macOS disk image (DMG) is executed. Malware authors may attempt to evade detection and trick users into executing malicious code by encoding and encrypting their payload and placing it in a disk image file. This behavior is consistent with adware or malware families such as Bundlore and Shlayer.
references:
- https://github.com/elastic/protections-artifacts/commit/746086721fd385d9f5c6647cada1788db4aea95f#diff-5d42c3d772e04f1e8d0eb60f5233bc79def1ea73105a2d8822f44164f77ef823
author: Tim Rauch (rule), Elastic (idea)
date: 2022-10-17
tags:
- attack.stealth
- attack.t1059
- attack.t1204
- attack.execution
- attack.t1140
- attack.s0482
- attack.s0402
logsource:
category: process_creation
product: macos
detection:
selection:
Image|endswith: '/openssl'
CommandLine|contains|all:
- '/Volumes/'
- 'enc'
- '-base64'
- ' -d '
condition: selection
falsepositives:
- Unknown
level: medium
False positives
- Unknown
Source references
Connected ecosystem references
Exact source-tagged techniques
Telemetry review
Read the original logsource above, then inspect the linked detection workspaces for technique-level sensor context. No per-rule telemetry equivalence is inferred.
Pinned research references. No browser attack runner, live simulation result or validated detector is asserted. Source mappings and validation limits are preserved. ATT&CK / Atomic provenance · Detection provenance.