Emerging Threathighstable

Potential Ryuk Ransomware Activity

Detects Ryuk ransomware activity

Convert In Phoenix Studio

Open this Sigma rule in the converter with the YAML preloaded and ready for backend selection.

Florian Roth (Nextron Systems), Vasiliy Burov, Nasreddine Bencherchali (Nextron Systems)Created Mon Dec 16Updated Fri Feb 03c37510b8-2107-4b78-aa32-72f251e7a8442019

Emerging Threat

Active Threat

Developed to detect an active or emerging threat. Prioritize investigation of any alerts and correlate with threat intelligence.

Log Source

WindowsProcess Creation

ProductWindows← raw: windows

CategoryProcess Creation← raw: process_creation

Events generated when a new process is spawned on the system. Covers command-line arguments, parent/child relationships, and process metadata.

Detection Logic

detection:
    selection_reg:
        CommandLine|contains|all:
            - 'Microsoft\Windows\CurrentVersion\Run'
            - 'C:\users\Public\'
    selection_del:
        CommandLine|contains|all:
            - 'del /s /f /q c:\'
            - '\*.bac'
            - '\*.bak'
            - '\*.bkf'
    selection_net:
        Image|endswith:
            - '\net.exe'
            - '\net1.exe'
        CommandLine|contains|all:
            - ' stop '
            - ' /y'
        CommandLine|contains:
            - 'samss'
            - 'audioendpointbuilder'
            - 'unistoresvc_'
            - 'AcrSch2Svc'
    condition: 1 of selection_*