This detection identifies adversaries attempting to bypass User Account Control (UAC) protections by loading specific DLLs, a common tactic used to elevate privileges and execute malicious code without triggering standard UAC prompts. SOC teams should proactively hunt for this behavior in Azure Sentinel because successful UAC bypasses often serve as a critical precursor to privilege escalation attacks that could compromise the integrity of endpoint security controls.
rule BypassUacDll_6 {
meta:
description = "Auto-generated rule - file BypassUacDll.aps"
author = "yarGen Yara Rule Generator"
hash = "58d7b24b6870cb7f1ec4807d2f77dd984077e531"
strings:
$s3 = "BypassUacDLL.dll" fullword wide
$s4 = "AFX_IDP_COMMAND_FAILURE" fullword ascii
condition:
all of them
}
This YARA rule can be deployed in the following contexts:
This rule contains 2 string patterns in its detection logic.
Here are 5 specific false positive scenarios for the BypassUacDll detection rule, including suggested filters and exclusions:
Scenario: Microsoft Endpoint Configuration Manager (SCCM) Application Deployment
consent.exe process with a specific DLL injection (BypassUacDll.aps) to silently install software without triggering a UAC prompt for the user. This is standard behavior during maintenance windows.ccmsetup.exe or WUAHandler.exe. Additionally, filter events where the file path matches C:\Windows\CCM\BypassUacDll.aps and the user context is SYSTEM or a specific SCCM service account (e.g., DOMAIN\SCCM-Service).Scenario: Scheduled Group Policy Software Installation
gpupdate or specific Group Policy Object (GPO) identifiers. Implement a time-based filter to exclude detections occurring strictly between 01:00 and 05:00 local time, assuming this is the designated maintenance window for GPO processing.Scenario: Antivirus Engine Self-Update via Silent Service
BypassUacDll logic to