Disclosed hacktool set (old stuff) - file EditServer.exe

Hunt Hypothesis

This rule detects adversaries deploying legacy or repurposed hacking tools like EditServer.exe to establish a foothold and execute malicious payloads within the environment. Proactive hunting for this behavior in Azure Sentinel is critical because older tooling often lacks modern security signatures, making it an ideal vector for stealthy lateral movement and command-and-control activities that may evade standard automated detections.

YARA Rule

rule EditServer_HackTool {
	meta:
		description = "Disclosed hacktool set (old stuff) - file EditServer.exe"
		author = "Florian Roth"
		date = "23.11.14"
		score = 60
		hash = "87b29c9121cac6ae780237f7e04ee3bc1a9777d3"
	strings:
		$s0 = "%s Server.exe" fullword ascii
		$s1 = "Service Port: %s" fullword ascii
		$s2 = "The Port Must Been >0 & <65535" fullword ascii
		$s8 = "3--Set Server Port" fullword ascii
		$s9 = "The Server Password Exceeds 32 Characters" fullword ascii
		$s13 = "Service Name: %s" fullword ascii
		$s14 = "Server Password: %s" fullword ascii
		$s17 = "Inject Process Name: %s" fullword ascii

		$x1 = "WinEggDrop Shell Congirator" fullword ascii
	condition:
		5 of ($s*) or $x1
}

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 9 string patterns in its detection logic.

• Source Rule

False Positive Guidance

Here are 5 specific false positive scenarios for the detection rule “Disclosed hacktool set (old stuff) - file EditServer.exe,” including targeted filters and exclusions:

• Scenario: Legacy ERP Maintenance Task

  • Context: An automated nightly maintenance job runs EditServer.exe within a legacy SAP or Oracle ERP environment to update server configurations. This executable is often located in C:\Program Files\LegacyERP\Bin\ rather than the standard system directory, causing the rule to flag it as an unknown “hacktool.”
  • Filter/Exclusion: Create a path-based exclusion for the specific legacy application folder: Path: C:\Program Files\LegacyERP\Bin\EditServer.exe. Additionally, exclude this file hash if it remains static across the enterprise.

• Scenario: Remote Desktop Management Tool

  • Context: System administrators utilize a third-party remote management suite (e.g., BeyondTrust or ManageEngine) where EditServer.exe is the core service executable used to modify server policies and user permissions during business hours. The file often resides in C:\Program Files\RemoteManagement\.
  • Filter/Exclusion: Implement an exclusion based on the parent process name. Filter out alerts where the parent process is RMMService.exe or BeyondTrustAgent.exe, as these are trusted orchestrators launching the tool legitimately.

• Scenario: Scheduled Database Backup Utility

  • Context: A scheduled Windows Task runs a custom backup utility named EditServer.exe (part of an older version of Veeam or a proprietary internal script) to archive transaction logs. This task executes every Sunday at 02:00 AM, triggering the detection when the file is accessed or modified by the backup engine.
  • Filter/Exclusion: Add a time-based filter to suppress