Detects .NET red/black-team tools via name

Hunt Hypothesis

This rule identifies the execution of known .NET-based offensive and defensive security tools by analyzing process names for signatures associated with Red Team and Blue Team activities. Proactively hunting for these indicators in Azure Sentinel allows the SOC team to distinguish legitimate security operations from potential adversary tooling that mimics trusted utilities, thereby reducing false positives and uncovering stealthy reconnaissance efforts.

YARA Rule

rule HKTL_NET_NAME_NativePayload_ARP {
    meta:
        description = "Detects .NET red/black-team tools via name"
        reference = "https://github.com/DamonMohammadbagher/NativePayload_ARP"
        author = "Arnim Rupp"
        date = "2021-01-22"
    strings:
        $name = "NativePayload_ARP" ascii wide
        $compile = "AssemblyTitle" ascii wide
    condition:
        (uint16(0) == 0x5A4D and uint32(uint32(0x3C)) == 0x00004550) and all of them
}

Deployment Notes

This YARA rule can be deployed in the following contexts:

• Microsoft Defender for Endpoint — Custom indicators / advanced hunting
• Email Gateway — Attachment scanning
• File Share Monitoring — Periodic scanning of shared drives
• YARA CLI — Manual threat hunting on endpoints

This rule contains 2 string patterns in its detection logic.

References

• https://github.com/DamonMohammadbagher/NativePayload_ARP
• Source Rule

False Positive Guidance

Here are 3-5 specific false positive scenarios for the rule “Detects .NET red/black-team tools via name,” including suggested filters and exclusions:

• Scenario: Automated Backup or Migration Scripts

  • Context: Enterprise IT teams often utilize PowerShell scripts wrapping .NET assemblies (e.g., BackupAgent.exe, DataMigrationTool.dll) that share naming conventions with security tools like RedTeamRunner or BlackBoxAnalyzer. These scripts run nightly via Task Scheduler to archive data, triggering the rule due to the ”.NET” and “tool-like” naming pattern.
  • Filter/Exclusion: Exclude processes where the command line contains specific keywords such as /backup, /migrate, or -task AND the user context is a dedicated service account (e.g., DOMAIN\svc_backup).

• Scenario: Software Deployment and Patching Agents

  • Context: Endpoint Management solutions like Microsoft SCCM, Ivanti, or ManageEngine often deploy .NET-based agents (DeploymentAgent.exe, PatchManager.dll) that execute installation packages. These tools frequently mimic the naming structure of red-team simulation tools (e.g., containing “Team”, “Agent”, or “Runner” in their filenames) during routine patch cycles.
  • Filter/Exclusion: Create a whitelist for known publisher hashes (e.g., Microsoft Corporation, Ivanti) and exclude processes running from standard deployment paths such as C:\Program Files\Microsoft SCCM or C:\ProgramData\Ivanti.

• Scenario: Internal DevOps CI/CD Pipeline Execution

  • Context: Development teams utilize internal .NET tools for Continuous Integration (e.g., BuildOrchestrator.exe, TestRunner.dll) that run on build servers or developer workstations. These tools often have names resembling security assessment frameworks used by the Red Team, causing false