cypherpunk-exclusive-commands

Hunt Hypothesis

The cypherpunk-exclusive-commands rule detects potential Cypherpunk ransomware activity through the execution of unique, adversary-specific commands that indicate tampering with antivirus solutions. SOC teams should proactively hunt for this behavior in Azure Sentinel to identify and mitigate ransomware attacks that evade traditional detection methods.

KQL Query

// Searches for possible Cypherpunk ransomware activity
DeviceProcessEvents
| where InitiatingProcessParentFileName startswith "psexe"
| where ProcessCommandLine has "Dvr /go"

Analytic Rule Definition

id: 2affa440-24b5-48b2-a377-d5968a499658
name: cypherpunk-exclusive-commands
description: |
  This query was originally published in the threat analytics report, Cypherpunk ransomware leaves wake of tampered AVs.
  Cypherpunk is a human-operated ransomware campaign named after the unusual .cypherpunk extension given to encrypted files.
  The query below surfaces commands that follow the distinctive pattern Cypherpunk operators would use to remotely execute code.
requiredDataConnectors:
- connectorId: MicrosoftThreatProtection
  dataTypes:
  - DeviceProcessEvents
tactics:
- Execution
- Ransomware
query: |
  // Searches for possible Cypherpunk ransomware activity
  DeviceProcessEvents
  | where InitiatingProcessParentFileName startswith "psexe"
  | where ProcessCommandLine has "Dvr /go"

Required Data Sources

MITRE ATT&CK Context

• Tactic: Execution
• Tactic: Ransomware

References

• [Source Query](https://github.com/Azure/Azure-Sentinel/blob/main/Hunting Queries/Microsoft 365 Defender/Campaigns/cypherpunk-exclusive-commands.yaml)

False Positive Guidance

• Scenario: A system administrator is using PowerShell to run a scheduled job that modifies registry keys for a legitimate endpoint protection tool (e.g., Microsoft Defender or Kaspersky).
  Filter/Exclusion: Exclude processes where the command line contains powershell.exe and the parent process is schtasks.exe or task scheduler.

• Scenario: A security analyst is performing a manual forensic analysis using Process Explorer or Wireshark to inspect network traffic for suspicious activity.
  Filter/Exclusion: Exclude processes where the command line includes ProcessExplorer.exe or Wireshark.exe and the user is a member of the Security or Administrators group.

• Scenario: A Windows Update task is running that temporarily modifies system files or registry entries to apply critical security patches.
  Filter/Exclusion: Exclude processes where the command line includes wuauclt.exe or WindowsUpdate.exe and the task is initiated by the Windows Update service.

• Scenario: A backup job is executed using Veeam Backup & Replication or Commvault that temporarily modifies or moves files during the backup process.
  Filter/Exclusion: Exclude processes where the command line includes Veeam.Backup.exe or cvbackup.exe and the task is associated with a known backup schedule.

• Scenario: A system cleanup task is run using CCleaner or Disk Cleanup that removes temporary files or modifies system settings.
  Filter/Exclusion: Exclude processes where the command line includes CCleaner.exe or cleanmgr.exe and the user is a member of the Administrators group.