ClickFix Infostealer Deployment via WebDAV and Pcalua
Score: 8/10

ClickFix Infostealer Deployment via WebDAV and Pcalua

ClickFix campaign leverages pcalua.exe and WMI to mount remote WebDAV shares for executing infostealer DLLs via rundll32.exe.

Executive Summary

A new ClickFix campaign has been identified using advanced social engineering to trick users into executing malicious commands that abuse legitimate Windows utilities. The attack chain begins with a social engineering prompt that leads to the execution of pcalua.exe, which subsequently leverages WMI and PowerShell to initiate a multi-stage infection process.

Technically, the campaign stands out by using the Program Compatibility Assistant (pcalua.exe) and WMI (Win32_Process) to spawn a hidden command shell. This shell mounts a remote, HTTPS-protected WebDAV share via the 'pushd' command, allowing the attacker to load a malicious DLL (gc.key) directly into memory using rundll32.exe. This method effectively bypasses many standard detection mechanisms that focus on direct file downloads.

This campaign represents a significant risk to organizations as it utilizes trusted binaries and encrypted WebDAV channels to deliver information-stealing malware. The infrastructure is characterized by short-lived TLS certificates and victim-specific UUID paths, indicating a sophisticated and highly targeted delivery mechanism.

Key Details

Threat Name

WebDAV DLL Side-Loading Campaign

Affects

—

Adversary

—

Malware/Tools

ClickFix, gc.key

Report Score

8out of 10
Quality Score
Good
IOC Quality9
TTP Details9
Detection Guidance6
Enterprise Relevance8
Clarity & Structure9
Technical Depth7

Sources