Sigma rule: Serpent Backdoor Payload Execution Via Scheduled Task

Rule

Title

Serpent Backdoor Payload Execution Via Scheduled Task

Status

test

Level

high

Author

@kostastsale

Date

2022-03-21

File

rules-emerging-threats/2022/Malware/Serpent-Backdoor/proc_creation_win_malware_serpent_backdoor_payload_execution.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

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.

Log source

product

windows

category

process_creation

Detection

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

False positives (as the rule lists them)

• Unlikely

Tags

• attack.privilege-escalation
• attack.execution
• attack.persistence
• attack.t1053.005
• attack.t1059.006
• detection.emerging-threats

MITRE ATT&CK ids this rule names

• T1053.005
• T1059.006

References

• https://www.proofpoint.com/us/blog/threat-insight/serpent-no-swiping-new-backdoor-targets-french-entities-unique-attack-chain

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules-emerging-threats/2022/Malware/Serpent-Backdoor/proc_creation_win_malware_serpent_backdoor_payload_execution.yml