Payload Decoded and Decrypted via Built-in Utilities

Title: Payload Decoded and Decrypted via Built-in Utilities
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
modified:None
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