Specifically, the alert detected a PowerShell command spawned by a suspicious executable named HoxLuSfo.exe. The MDR SOC first became aware of this malware campaign upon analysis of “UAC Bypass - Disk Cleanup Utility” and “Suspicious Process - TaskKill Multiple Times” alerts (authored by Rapid7's TIDE team) within Rapid7's InsightIDR platform.Īs the “UAC Bypass - Disk Cleanup Utility” name implies, the alert identified a possible UAC bypass using the Disk Cleanup utility due to a vulnerability in some versions of Windows 10 that allows a native scheduled task to execute arbitrary code by modifying the content of an environment variable. The malware is classified as a stealer, which intends to steal sensitive data from an infected asset (such as browser credentials and cryptocurrency), prevent browser updates, and allow for arbitrary command execution. Recently, we identified a malware campaign whose payload installs itself as a Windows application after delivery via a browser ad service and bypasses User Account Control (UAC) by abusing a Windows environment variable and a native scheduled task to ensure it persistently executes with elevated privileges. Rapid7's Managed Detection and Response (MDR) team leverages specialized toolsets, malware analysis, tradecraft, and collaboration with our colleagues on the Threat Intelligence and Detection Engineering (TIDE) team to detect and remediate threats.

This post also includes contributions from Reese Lewis, Andrew Christian, and Seth Lazarus.

Microsoft malware tool