Emerging Threathightest

Serpent Backdoor Payload Execution Via Scheduled Task

Detects post exploitation execution technique of the Serpent backdoor. According to Proofpoint, one of the commands that the backdoor ran was via creating a temporary scheduled task using an unusual method. It creates a fictitious windows event and a trigger in which once the event is created, it executes the payload.

Convert In Phoenix Studio

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

Launch

kostastsaleCreated Mon Mar 21d5eb7432-fda4-4bba-a37f-ffa74d9ed6392022

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:
        Image|endswith:
            - '\cmd.exe'
            - '\powershell.exe'
        CommandLine|contains|all:
            - '[System/EventID='
            - '/create'
            - '/delete'
            - '/ec'
            - '/so'
            - '/tn run'
    condition: selection