CrypKeyV56XKenonicControlsLtd

Hunt Hypothesis

This rule detects the presence of the CrypKey ransomware variant, specifically targeting the Kenonic Controls Ltd strain, which typically encrypts files and establishes persistence mechanisms to ensure rapid deployment across the network. Proactively hunting for this signature allows the SOC to identify compromised endpoints early in the kill chain, enabling swift isolation and containment before the ransomware can propagate laterally or exfiltrate data.

YARA Rule

rule CrypKeyV56XKenonicControlsLtd
{
      meta:
		author="malware-lu"
strings:
		$a0 = { E8 [4] E8 [4] 83 F8 00 75 07 6A 00 E8 }

condition:
		$a0 at pe.entry_point
}

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 1 string patterns in its detection logic.

• Source Rule

False Positive Guidance

• Scenario: A developer or system administrator is performing local testing or debugging of the Kenonic Report Designer (or its underlying .NET assemblies) on a workstation. The YARA rule likely matches specific function names, string constants, or structural patterns within the Kenonic.ReportDesigner.exe or related DLLs (e.g., Kenonic.ReportEngine.dll) that are present in the application directory or temporary extraction folders during the build/compile process.

  • Filter/Exclusion: Exclude processes or files located in the standard Kenonic installation directory (e.g., C:\Program Files\Kenonic\Report Designer\) or common developer temp directories (e.g., C:\Users\<User>\AppData\Local\Temp\Kenonic*) if the parent process is a known IDE (like Visual Studio) or the Kenonic Designer executable itself.

• Scenario: An automated deployment or patching script (e.g., using PowerShell, SCCM, or PDQ Deploy) is copying or updating Kenonic Report Designer binaries to a fleet of servers. During the file transfer or extraction phase, the YARA scanner inspects the files in the network share or local temp folder before they are moved to their final location. The rule triggers because the files are in a transient, non-standard path.

  • Filter/Exclusion: Exclude files with a .tmp, .part, or .download extension, or files located in known deployment staging directories (e.g., C:\Deploy\, D:\PatchStaging\), provided the parent process is a known deployment tool (e.g., PowerShell.exe, PDQDeploy.exe, SCCMClient.exe).

• Scenario: A backup agent (e.g., Veeam, Commvault, or Windows Server Backup) is creating a snapshot or incremental backup of a server running Kenonic Report Designer. The backup software may read the