An LNK file is a Windows shortcut. It does not contain the target document or program itself; instead, it stores a path, optional arguments, and display details that tell Windows what to open when the shortcut is clicked. Because the icon and filename can be made to look ordinary, LNK files are useful to attackers who want a malicious action to feel like a normal user action.
In cyber security, LNK files matter because they are often used in phishing and malware delivery. A shortcut can point to a script, launcher, or legitimate tool being abused to start hidden execution, so the risk is not the file alone but what happens after the click. Defenders look for suspicious shortcuts in email attachments, archives, and downloaded files, especially when they trigger PowerShell, cmd.exe, or other unusual child processes. Extension checks help, but behavior monitoring is usually more reliable than trusting the icon.