Small Sieve Malware Potential C2 Communication

title: Small Sieve Malware Potential C2 Communication
id: b0422664-37a4-4e78-949a-4a139309eaf0
status: test
description: Detects potential C2 communication related to Small Sieve malware
references:
    - https://www.ncsc.gov.uk/static-assets/documents/malware-analysis-reports/goofy-guineapig/NCSC-MAR-Goofy-Guineapig.pdf
author: Nasreddine Bencherchali (Nextron Systems)
date: 2023-05-19
tags:
    - attack.command-and-control
    - detection.emerging-threats
logsource:
    category: proxy
detection:
    selection:
        cs-method: 'GET'
        cs-host: 'api.telegram.org'
        cs-uri|contains|all:
            - 'chat_id=2090761833'
            - 'text=com/'
    condition: selection
falsepositives:
    - Unlikely
level: critical