Sigma rule: Payload Decoded and Decrypted via Built-in Utilities

Rule

Title

Payload Decoded and Decrypted via Built-in Utilities

Status

test

Level

medium

Author

Tim Rauch (rule), Elastic (idea)

Date

2022-10-17

File

rules/macos/process_creation/proc_creation_macos_payload_decoded_and_decrypted.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

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.

Log source

product

macos

category

process_creation

Detection

selection:
    Image|endswith: '/openssl'
    CommandLine|contains|all:
        - '/Volumes/'
        - 'enc'
        - '-base64'
        - ' -d '
condition: selection

False positives (as the rule lists them)

• Unknown

Tags

• attack.stealth
• attack.t1059
• attack.t1204
• attack.execution
• attack.t1140
• attack.s0482
• attack.s0402

MITRE ATT&CK ids this rule names

• S0402
• S0482
• T1059
• T1140
• T1204

References

• https://github.com/elastic/protections-artifacts/commit/746086721fd385d9f5c6647cada1788db4aea95f#diff-5d42c3d772e04f1e8d0eb60f5233bc79def1ea73105a2d8822f44164f77ef823

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/macos/process_creation/proc_creation_macos_payload_decoded_and_decrypted.yml