Thursday, May 8, 2025
HomeCyber Security NewsHackers Bypassed Windows Defender Policies Using WinDbg Preview via Microsoft Store

Hackers Bypassed Windows Defender Policies Using WinDbg Preview via Microsoft Store

Published on

SIEM as a Service

Follow Us on Google News

A newly documented technique reveals how attackers can exploit the WinDbg Preview debugger to bypass even the strictest Windows Defender Application Control (WDAC) policies, raising concerns about a significant gap in enterprise security controls.

The exploit, dubbed the “WinDbg Preview Exploit,” leverages the debugger’s advanced capabilities to achieve code execution and remote process injection, effectively sidestepping defenses that would otherwise block unsigned or unauthorized code.

How the Exploit Works

According to the CerberSec report, the attack starts in a tightly locked-down environment, often configured with robust WDAC policies.

- Advertisement - Google News

These policies are designed to prevent the execution of any unsigned executables or DLLs, and commonly used system tools (known as “living-off-the-land binaries” or LOLBins) are typically blocked as well.

However, many organizations leave the Microsoft Store enabled, allowing users to install applications like WinDbg Preview (WinDbgX.exe), which is not included in Microsoft’s default WDAC blocklist.

Once WinDbg Preview is installed, an attacker can use it to inject arbitrary shellcode into a target process.

The process involves converting the shellcode into a WinDbg script format and loading it byte-by-byte into memory using the debugger’s scripting capabilities.

The attacker then uses WinDbg commands to call Windows API functions such as OpenProcess, VirtualAllocEx, WriteProcessMemory, and CreateRemoteThread, effectively injecting and executing code in another process—even when all standard execution paths are blocked by WDAC.

The exploit does not rely on traditional executable files or DLLs, which are typically scrutinized and blocked by WDAC.

Instead, it abuses the trusted status of WinDbg Preview, a legitimate debugging tool, to perform actions that would otherwise be prohibited.

This technique highlights a critical oversight in many organizations’ security postures.

While Microsoft maintains a recommended blocklist for WDAC, it currently includes the legacy windbg.exe but not the newer WinDbg Preview installed via the Microsoft Store. 

As a result, attackers can exploit this gap to gain code execution on systems presumed to be secure.

Security experts recommend several mitigations:

  • Update WDAC blocklists to explicitly include WinDbg Preview (WinDbgX.exe), not just legacy versions.
  • Disable the Microsoft Store on endpoints where it is not required, reducing the risk of users installing potentially exploitable tools.
  • Monitor for suspicious use of debugging tools, especially those that invoke process injection techniques or frequent calls to APIs like SetThreadContext().

The “WinDbg Preview Exploit Lets Attackers Evade Windows Defender Policies” serves as a stark reminder that security is only as strong as its weakest link.

Organizations must proactively review and update their WDAC policies, ensuring that all potential vectors—including modern debugging tools—are accounted for and appropriately restricted.

Find this News Interesting! Follow us on Google NewsLinkedIn, & X to Get Instant Updates!

Divya
Divya
Divya is a Senior Journalist at GBhackers covering Cyber Attacks, Threats, Breaches, Vulnerabilities and other happenings in the cyber world.

Latest articles

Top Ransomware Groups Target Financial Sector, 406 Incidents Revealed

Flashpoint analysts have reported that between April 2024 and April 2025, the financial sector...

Agenda Ransomware Group Enhances Tactics with SmokeLoader and NETXLOADER

The Agenda ransomware group, also known as Qilin, has been reported to intensify its...

SpyCloud Analysis Reveals 94% of Fortune 50 Companies Have Employee Data Exposed in Phishing Attacks

SpyCloud, the leading identity threat protection company, today released an analysis of nearly 6...

PoC Tool Released to Detect Servers Affected by Critical Apache Parquet Vulnerability

F5 Labs has released a new proof-of-concept (PoC) tool designed to help organizations detect...

Resilience at Scale

Why Application Security is Non-Negotiable

The resilience of your digital infrastructure directly impacts your ability to scale. And yet, application security remains a critical weak link for most organizations.

Application Security is no longer just a defensive play—it’s the cornerstone of cyber resilience and sustainable growth. In this webinar, Karthik Krishnamoorthy (CTO of Indusface) and Phani Deepak Akella (VP of Marketing – Indusface), will share how AI-powered application security can help organizations build resilience by

Discussion points


Protecting at internet scale using AI and behavioral-based DDoS & bot mitigation.
Autonomously discovering external assets and remediating vulnerabilities within 72 hours, enabling secure, confident scaling.
Ensuring 100% application availability through platforms architected for failure resilience.
Eliminating silos with real-time correlation between attack surface and active threats for rapid, accurate mitigation

More like this

Top Ransomware Groups Target Financial Sector, 406 Incidents Revealed

Flashpoint analysts have reported that between April 2024 and April 2025, the financial sector...

Agenda Ransomware Group Enhances Tactics with SmokeLoader and NETXLOADER

The Agenda ransomware group, also known as Qilin, has been reported to intensify its...

PoC Tool Released to Detect Servers Affected by Critical Apache Parquet Vulnerability

F5 Labs has released a new proof-of-concept (PoC) tool designed to help organizations detect...