This YARA rule targets specific memory signatures associated with the PCGuardv303dv305d component, likely indicating the presence of a legacy or embedded protection mechanism that may be leveraged by adversaries for persistence or process injection. Proactively hunting for this signature in Azure Sentinel allows the SOC team to identify low-severity anomalies or dormant payloads that standard behavioral detections might miss, ensuring comprehensive coverage of the endpoint attack surface.
rule PCGuardv303dv305d
{
meta:
author="malware-lu"
strings:
$a0 = { 55 50 E8 [4] 5D EB 01 E3 60 E8 03 [3] D2 EB 0B 58 EB 01 48 40 EB 01 }
condition:
$a0 at pe.entry_point
}
This YARA rule can be deployed in the following contexts:
This rule contains 1 string patterns in its detection logic.
Scenario: A legacy Java-based Enterprise Resource Planning (ERP) module (e.g., SAP NetWeaver or Oracle EBS) is running on a Windows server and utilizes the PCGuard driver for hardware-level security or dongle protection. The YARA rule may match the generic memory footprint or specific byte sequences within the pcguard.sys or associated user-mode drivers loaded by the Java Virtual Machine (JVM).
java.exe or javaw.exe and the image path contains \pcguard\ or \dongle\. Alternatively, exclude hosts tagged with AppGroup=ERP-Legacy if the driver is only present on specific application servers.Scenario: An IT administrator performs a manual integrity check or backup verification using a third-party disk imaging tool (e.g., Acronis True Image, Veeam Agent, or Symantec System Recovery) that loads the PCGuard driver to bypass file locks or access protected sectors during the snapshot process.
Daily_Backup_Veeam) or if the parent process is agent.exe (Veeam) or trueimage.exe (Acronis), suppress the alert. Add an exclusion for processes with command lines containing --backup or --snapshot.Scenario: A corporate endpoint protection suite (e.g., Kaspersky Endpoint Security, ESET NOD32, or Bitdefender GravityZone) updates its driver components or performs a full-system scan, temporarily loading the PCGuard driver for low-level disk access or memory protection features.
klnagent.exe, `ekrn.exe