RPX v1.XX

Hunt Hypothesis

This rule detects the presence of the RPX v1.XX component, which may indicate the deployment of a specific remote access or management tool within the environment. Proactively hunting for this signature allows the SOC team to identify potentially unmanaged or legacy software that could serve as an entry point for adversaries or a vector for lateral movement.

YARA Rule

rule rpx_1_xx : Packer
{
	meta:
		author="Kevin Falcoz"
		date_create="24/03/2013"
		description="RPX v1.XX"

	strings:
		$signature1= "RPX 1."
		$signature2= "Copyright 20"

	condition:
		$signature1 and $signature2
}

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.

• Source Rule

False Positive Guidance

• Scenario: A DevOps engineer executes a standard kubectl apply command to deploy a new StatefulSet or DaemonSet in the Kubernetes cluster, which triggers the rule due to the creation of new pod resources or associated RBAC bindings.
  • Filter/Exclusion: Exclude events where the user agent or source process is kubectl and the namespace is within the approved production or staging namespaces, specifically filtering out API calls to /v1/namespaces/{ns}/pods or /v1/namespaces/{ns}/serviceaccounts initiated by the system:serviceaccount:kube-system:default or known CI/CD service accounts.
• Scenario: The enterprise backup solution (e.g., Veeam Backup & Replication or Commvault) performs a scheduled nightly full backup of the SQL Server database, creating temporary backup files and associated transaction log truncation events that match the rule’s file creation or permission change criteria.
  • Filter/Exclusion: Exclude file creation events where the source process is vbr.exe (Veeam Backup and Replication) or cvbackup.exe (Commvault) and the destination path contains \Backup\ or \VeeamBackup\, provided the file extension is .vbk, .vib, or .trn.
• Scenario: An IT administrator runs the Windows Update Agent (wuauclt.exe) or the UpdateOrchestrator service to install cumulative security patches, which results in the creation of new DLLs in C:\Windows\WinSxS\ or the execution of setup.exe from the C:\Windows\SoftwareDistribution\ folder.
  • Filter/Exclusion: Exclude execution or file creation events where the process name is wuauclt.exe, UpdateOrchestrator.exe, or `trusted