The detection identifies potential adversary activity involving the file HRDG022184_certclint.dll, which may be used for credential access or persistence. SOC teams should proactively hunt for this behavior in Azure Sentinel to identify and mitigate early-stage threats that could lead to deeper compromise.
YARA Rule
rule GRIZZLY_STEPPE_Malware_1
{
meta:
description = "Auto-generated rule - file HRDG022184_certclint.dll"
author = "Florian Roth"
reference = "https://goo.gl/WVflzO"
date = "2016-12-29"
hash1 = "9f918fb741e951a10e68ce6874b839aef5a26d60486db31e509f8dcaa13acec5"
strings:
$s1 = "S:\\Lidstone\\renewing\\HA\\disable\\In.pdb" fullword ascii
$s2 = "Repeat last find command)Replace specific text with different text" fullword wide
$s3 = "l\\Processor(0)\\% Processor Time" fullword wide
$s6 = "Self Process" fullword wide
$s7 = "Default Process" fullword wide
$s8 = "Star Polk.exe" fullword wide
condition:
( uint16(0) == 0x5a4d and filesize < 300KB and 4 of them )
}This YARA rule can be deployed in the following contexts:
This rule contains 6 string patterns in its detection logic.
Scenario: A system administrator is using Microsoft System Center Configuration Manager (SCCM) to deploy updates, and the file HRDG022184_certclint.dll is part of a legitimate update package.
Filter/Exclusion: Check for processes associated with sccm.exe or mpcmdrun.exe (Microsoft Endpoint Protection), or filter by the presence of SCCM in the process name.
Scenario: A scheduled job runs Windows Task Scheduler to execute a script that temporarily creates or modifies the HRDG022184_certclint.dll file as part of a legitimate system maintenance task.
Filter/Exclusion: Filter events where the process is schtasks.exe or where the file modification is associated with a known scheduled task name.
Scenario: A Microsoft Intune deployment includes the HRDG022184_certclint.dll file as part of a certificate management tool, and the file is being accessed during a policy update.
Filter/Exclusion: Check for processes related to intunewin.exe or Microsoft Intune in the process tree, or filter by the presence of Intune in the process name.
Scenario: A Windows Update installation process includes the HRDG022184_certclint.dll file as part of a certificate validation step during OS updates.
Filter/Exclusion: Filter for processes related to wuauserv or svchost.exe with the Windows Update service, or check for the presence of WindowsUpdate in the process name.
Scenario: A Microsoft Defender for Endpoint scan or update process includes the HRDG022184_certclint.dll file as part of its internal operations.
**Filter/