Description

A newly revealed issue in Windows shortcut files (LNK) may let attackers run malicious code remotely without user action. Researcher Nafiez has shared a working demonstration showing that simply viewing a folder containing a harmful shortcut can trigger the exploit. The weakness stems from how Windows Explorer automatically handles LNK files. By modifying specific parts of the shortcut’s data structure—such as using environment variables and linking to remote file paths—attackers can craft files that initiate background network activity. This process is carried out through system components like IInitializeNetworkFolder as soon as the folder is opened. Microsoft has chosen not to fix the issue, claiming it does not meet their standard for updates. They argue that the Mark of the Web feature, which flags downloaded files for extra scrutiny, is enough to reduce the danger. However, security professionals warn this method can be bypassed, including through a long-known method called LNK stomping. LNK files have previously been misused in security breaches, with notable examples in 2010 and 2017. The public release of the proof of concept raises the likelihood that this flaw will be used in real-world attacks. To lower risk, users should avoid opening folders from unknown or untrusted sources. Administrators are encouraged to monitor traffic for suspicious behavior and use detection tools like Responder to identify unauthorized NTLM hash capture attempts.