Disclosed hacktool set - file 445.rar

Hunt Hypothesis

This detection rule identifies adversaries deploying compressed archive files containing hacking tools to establish a persistent foothold and evade initial signature-based defenses within the Azure Sentinel environment. Proactive hunting for this behavior is critical to uncover early-stage lateral movement or command-and-control activities that may be obscured by legitimate file transfer operations, allowing the SOC team to mitigate potential compromises before they escalate.

YARA Rule

rule Hacktools_CN_Panda_445 {
	meta:
		description = "Disclosed hacktool set - file 445.rar"
		author = "Florian Roth"
		date = "17.11.14"
		score = 60
		hash = "a61316578bcbde66f39d88e7fc113c134b5b966b"
	strings:
		$s0 = "for /f %%i in (ips.txt) do (start cmd.bat %%i)" fullword ascii
		$s1 = "445\\nc.exe" fullword ascii
		$s2 = "445\\s.exe" fullword ascii
		$s3 = "cs.exe %1" fullword ascii
		$s4 = "445\\cs.exe" fullword ascii
		$s5 = "445\\ip.txt" fullword ascii
		$s6 = "445\\cmd.bat" fullword ascii
		$s9 = "@echo off" fullword ascii
	condition:
		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 8 string patterns in its detection logic.

• Source Rule

False Positive Guidance

Here are 3-5 specific false positive scenarios for the “Disclosed hacktool set - file 445.rar” detection rule, including suggested filters and exclusions:

• Scenario: Automated Backup of Security Tools by IT Admin

  • Context: An IT administrator uses a script to archive the latest version of the “HackTool Set” (a collection of diagnostic utilities) into 445.rar for distribution to the helpdesk. This often occurs during off-hours via a scheduled task.
  • Suggested Filter/Exclusion: Exclude files named 445.rar when generated by specific administrative accounts (e.g., DOMAIN\IT-Admin, DOMAIN\Backup-Svc) or when the parent process is a known backup utility like Veeam Backup & Replication or Robocopy.

• Scenario: Deployment of Patched Diagnostic Suite via SCCM

  • Context: The System Center Configuration Manager (SCCM) deploys an updated diagnostic toolkit to endpoint workstations. The deployment package is wrapped in a RAR archive named 445.rar containing the “HackTool Set” for software inventory and hardware diagnostics.
  • Suggested Filter/Exclusion: Create a rule exclusion where the parent process is ccmsetup.exe or wuauserv.exe, and the file path matches the standard deployment directory (e.g., C:\Windows\CCMCache\...).

• Scenario: Scheduled Maintenance Job for Remote Support Tools

  • Context: A nightly scheduled job runs to compress remote support tools (such as TeamViewer, AnyDesk, or BeyondTrust) into a single archive named 445.rar before pushing them to the network share. The detection logic flags this compression activity as a potential “hacktool” disclosure event.

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