Query: detection rule: Detects base64 encoded strings used in hidden malicious PowerShell command lines
Matching passage: Sigma rule: Detects base64 encoded strings used in hidden malicious PowerShell command lines. Logsource: windows / process_creation. Rule: title: Malicious Base64 Encoded PowerShell Keywords in Command Lines id: f26c6093-6f14-4b12-800f-0fcb46f5ffd0 status: test description: Detects base64 encoded strings used in hidden malicious PowerShell command lines references: - http://www.leeholmes.com/blog/2017/09/21/searching-for-content-in-base-64-strings/ author: John Lambert (rule) date: 2019-01-16 modified: 2023-01-05 tags: - attack.execution - attack.t1059.001 logsource: category: process_creation product: windows detection: selection_img: - Image|endswith: - \powershell.exe - \pwsh.exe - OriginalFileName: - PowerShell.EXE - pwsh.dll selection_hidden: CommandLine|contains: ' hidden ' selection_encoded: CommandLine|contains: - AGkAdABzAGEAZABtAGkAbgAgAC8AdAByAGEAbgBzAGYAZQByA - aXRzYWRtaW4gL3RyYW5zZmVy - IAaQB0AHMAYQBkAG0AaQBuACAALwB0AHIAYQBuAHMAZgBlAHIA - JpdHNhZG1pbiAvdHJhbnNmZX - YgBpAHQAcwBhAGQAbQBpAG4AIAAvAHQAcgBhAG4AcwBmAGUAcg - Yml0c2FkbWluIC90cmFuc2Zlc - AGMAaAB1AG4AawBfAHMAaQB6AGUA - JABjAGgAdQBuAGsAXwBzAGkAegBlA - JGNodW5rX3Npem - QAYwBoAHUAbgBrAF8AcwBpAHoAZQ - RjaHVua19zaXpl - Y2h1bmtfc2l6Z - AE8ALgBDAG8AbQBwAHIAZQBzAHMAaQBvAG4A - kATwAuAEMAbwBtAHAAcgBlAHMAcwBpAG8Abg - lPLkNvbXByZXNzaW9u - SQBPAC4AQwBvAG0AcAByAGUAcwBzAGkAbwBuA - SU8uQ29tcHJlc3Npb2 - Ty5Db21wcmVzc2lvb - AE8ALgBNAGUAbQBvAHIAeQBTAHQAcgBlAGEAbQ - kATwAuAE0AZQBtAG8AcgB5AFMAdAByAGUAYQBtA - lPLk1lbW9yeVN0cmVhb - SQBPAC4ATQBlAG0AbwByAHkAUwB0AHIAZQBhAG0A - SU8uTWVtb3J5U3RyZWFt - Ty5NZW1vcnlTdHJlYW - 4ARwBlAHQAQwBoAHUAbgBrA - 5HZXRDaHVua - AEcAZQB0AEMAaAB1AG4Aaw - LgBHAGUAdABDAGgAdQBuAGsA - LkdldENodW5r - R2V0Q2h1bm - AEgAUgBFAEEARABfAEkATgBGAE8ANgA0A - QASABSAEUAQQBEAF8ASQBOAEYATwA2ADQA - RIUkVBRF9JTkZPNj - SFJFQURfSU5GTzY0 - VABIAFIARQBBAEQAXwBJAE4ARgBPADYANA - VEhSRUFEX0lORk82N - AHIAZQBhAHQAZQBSAGUAbQBvAHQAZQBUAGgAcgBlAGEAZA - cmVhdGVSZW1vdGVUaHJlYW - MAcgBlAGEAdABlAFIAZQBtAG8AdABlAFQAaAByAGUAYQBkA - NyZWF0ZVJlbW90ZVRocmVhZ - Q3JlYXRlUmVtb3RlVGhyZWFk - QwByAGUAYQB0AGUAUgBlAG0AbwB0AGUAVABoAHIAZQBhAGQA - 0AZQBtAG0AbwB2AGUA - 1lbW1vdm - AGUAbQBtAG8AdgBlA - bQBlAG0AbQBvAHYAZQ - bWVtbW92Z - ZW1tb3Zl condition: all of selection_* falsepositives: - Unknown level: high
Near-miss passage: Sigma rule: Detects when the macOS Script Editor utility spawns an unusual child process.. Logsource: macos / process_creation. Rule: title: Suspicious Execution via macOS Script Editor id: 6e4dcdd1-e48b-42f7-b2d8-3b413fc58cb4 status: test description: Detects when the macOS Script Editor utility spawns an unusual child process. author: Tim Rauch (rule), Elastic (idea) references: - https://github.com/elastic/protections-artifacts/commit/746086721fd385d9f5c6647cada1788db4aea95f#diff-7f541fbc4a4a28a92970e8bf53effea5bd934604429112c920affb457f5b2685 - https://wojciechregula.blog/post/macos-red-teaming-initial-access-via-applescript-url/ date: 2022-10-21 modified: 2022-12-28 logsource: category: process_creation product: macos tags: - attack.defense-impairment - attack.t1566 - attack.t1566.002 - attack.initial-access - attack.t1059 - attack.t1059.002 - attack.t1204 - attack.t1204.001 - attack.execution - attack.persistence - attack.t1553 detection: selection_parent: ParentImage|endswith: /Script Editor selection_img: - Image|endswith: - /curl - /bash - /sh - /zsh - /dash - /fish - /osascript - /mktemp - /chmod - /php - /nohup - /openssl - /plutil - /PlistBuddy - /xattr - /sqlite - /funzip - /popen - Image|contains: - python - perl condition: all of selection_* falsepositives: - Unknown level: medium