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Windows Zero-Day Threat: Protect Your NTLM Credentials

Reading time: 2 Minutes Read
Roy Ludmir
Updated on: May 21, 2025
Windows Zero-Day Threat: Protect Your NTLM Credentials

A newly discovered zero-day vulnerability in Windows potentially exposes users across multiple Windows versions to credential theft. Discovered by 0patch researchers, this critical security flaw allows attackers to steal NTLM credentials through a deceptively simple method.

What Makes This Vulnerability Dangerous?

Widespread Impact

The vulnerability affects a wide range of Windows systems, including:

  • Windows 7 and Server 2008 R2
  • Windows 10 (multiple versions)
  • Windows 11 (up to v24H2)
  • Windows Server 2022

Exploitation Mechanism

Technical details of the vulnerability are withheld to minimize exploitation risk until Microsoft issues a fix to minimize any further risk of exploitation.

The vulnerability enables attackers to steal a user’s NTLM credentials by luring them into opening a malicious file in Windows Explorer.

Attackers can trigger the vulnerability through minimal user interaction:

  • Opening a shared folder
  • Accessing a USB disk
  • Simply viewing a malicious file in Windows Explorer
  • Accessing the Downloads folder with a strategically placed file

Issues with Unpatched Vulnerabilities

This isn’t an isolated incident. The same research team has previously identified multiple unresolved Windows vulnerabilities, including:

  • Windows Theme file issue
  • “Mark of the Web” vulnerability
  • “EventLogCrasher” vulnerability
  • Three NTLM-related vulnerabilities (PetitPotam, PrinterBug/SpoolSample, and DFSCoerce)

0patch Micropatches

0patch is offering a free micropatch for the latest NTLM zero-day to all users registered on its platform until Microsoft releases an official fix.

The security micropatch has already been automatically deployed to PRO and Enterprise accounts, except in cases where configurations explicitly block automatic updates.

 

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Focusing on the proactive approach

While automated systems have already applied the patch to PRO and Enterprise accounts, a proactive approach to minimizing risks is to always have your servers hardened.

This proactive approach dramatically reduces the attack surface by ensuring consistent security configurations are rapidly applied across all systems, effectively shrinking the critical timeframe when servers remain exposed to newly discovered vulnerabilities like the recent NTLM zero-day exploit. Get in Touch to find out more.

Roy Ludmir
Roy Ludmir is a cybersecurity entrepreneur and CEO with over 15 years of experience driving product innovation and sales growth in the security industry. He is highly skilled in CIS Benchmarks, baseline hardening, and vulnerability management, helping organizations strengthen defenses and meet compliance requirements. With a unique blend of executive leadership and deep technical expertise, he bridges business strategy with practical security solutions.

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