Detects .NET red/black-team tools via name

Hunt Hypothesis

This hypothesis seeks to identify the execution of known .NET-based red and blue team utility names that may indicate legitimate security testing or potential adversary tooling masquerading as benign operations. Proactively hunting for these artifacts in Azure Sentinel is essential to distinguish between authorized internal exercises and malicious activity, ensuring that low-severity signals do not obscure critical threats within the environment.

YARA Rule

rule HKTL_NET_NAME_metasploit_sharp {
    meta:
        description = "Detects .NET red/black-team tools via name"
        reference = "https://github.com/VolatileMindsLLC/metasploit-sharp"
        author = "Arnim Rupp"
        date = "2021-01-22"
    strings:
        $name = "metasploit-sharp" 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/VolatileMindsLLC/metasploit-sharp
• Source Rule

False Positive Guidance

Here are 5 specific false positive scenarios for the rule “Detects .NET red/blue-team tools via name,” along with suggested filters or exclusions:

• Scenario: A scheduled backup job utilizing Veeam Backup & Replication (which relies heavily on .NET assemblies) executes during business hours, triggering the rule due to filenames like Veeam.Backup.Core.exe matching generic ”.NET tool” patterns.

  • Suggested Filter/Exclusion: Add an exclusion for the specific process path C:\Program Files\Veeam\Backup and Replication\... or filter out events where the parent process is Veeam.Backup.Service.exe.

• Scenario: The IT operations team runs a custom internal compliance scanner named ComplianceAudit.Net via a PowerShell script during end-of-month audits, which mimics the naming convention of known red-team tools.

  • Suggested Filter/Exclusion: Create an allow-list for the specific executable name ComplianceAudit.Net.exe running under the service account DOMAIN\svc-audit, or exclude processes launched by the parent process powershell.exe with a command line containing “audit-scan”.

• Scenario: The deployment of a new ServiceNow agent update involves the execution of ServiceNow.Agent.exe, a .NET-based application that performs system inventory checks, which overlaps with the detection logic for black-team reconnaissance tools.

  • Suggested Filter/Exclusion: Exclude processes where the file path contains \Program Files\ServiceNow\ and the publisher is “The ServiceNow, Inc.” to distinguish it from custom red-team .NET payloads.

• Scenario: A developer on a build server runs Octopus Deploy tentacle services (Tentacle.exe) which are .NET applications used for continuous integration/continuous deployment (CI/CD) pipelines, often generating alerts when they