Sigma Rule Library

Potential Compromised 3CXDesktopApp ICO C2 File Download

Detects potential malicious .ICO files download from a compromised 3CXDesktopApp via web requests to the the malicious Github repository

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Detection logic

selection

c-uri|contains|all:
  - IconStorages/images/main/icon
  - .ico

Condition

selection

Raw YAML

title: Potential Compromised 3CXDesktopApp ICO C2 File Download
id: 76bc1601-9546-4b75-9419-06e0e8d10651
related:
    - id: 3c4b3bbf-36b4-470c-b6cf-f07e8b1c7e26 # Proxy C2
      type: similar
    - id: bd03a0dc-5d93-49eb-b2e8-2dfd268600f8 # DNS C2
      type: similar
    - id: 51eecf75-d069-43c7-9ea2-63f75499edd4 # net_connection C2
      type: similar
    - id: 93bbde78-dc86-4e73-9ffc-ff8a384ca89c # ProcCreation Exec
      type: similar
    - id: 63f3605b-979f-48c2-b7cc-7f90523fed88 # ProcCreation ChildProc
      type: similar
    - id: e7581747-1e44-4d4b-85a6-0db0b4a00f2a # ProcCreation Update
      type: similar
    - id: d0b65ad3-e945-435e-a7a9-438e62dd48e9 # ImageLoad
      type: similar
status: test
description: Detects potential malicious .ICO files download from a compromised 3CXDesktopApp via web requests to the the malicious Github repository
references:
    - https://www.sentinelone.com/blog/smoothoperator-ongoing-campaign-trojanizes-3cx-software-in-software-supply-chain-attack/
    - https://www.linkedin.com/feed/update/urn:li:activity:7047435754834198529/
author: Nasreddine Bencherchali (Nextron Systems)
date: 2023-03-31
tags:
    - attack.command-and-control
    - detection.emerging-threats
logsource:
    category: proxy
detection:
    selection:
        c-uri|contains|all:
            - 'IconStorages/images/main/icon'
            - '.ico'
    condition: selection
falsepositives:
    - Unknown
level: high

False positives

  • Unknown

References

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