lnk

lnk is the file extension used by Windows for shortcut files. A .lnk file, also called a Shell Link, is a binary file that stores a reference to another item on the system, such as an executable, document, folder, or URL. When opened, the operating system resolves the target and launches or navigates to it. Shortcuts are commonly used to provide quick access to frequently used programs or files without requiring the user to know the exact path.

The Shell Link binary format contains several data structures, including a LinkTargetIDList, a LinkInfo section, and various string fields such as WorkingDirectory, RelativePath, CommandLineArguments, and IconLocation. Strings may be stored as Unicode. The target path can be absolute or relative, and the file may also store the display name and description. The format is designed to be interpreted by the Windows Shell, and access to or manipulation of shortcuts is typically performed through COM interfaces such as IShellLink and IPersistFile.

Creation and usage: Shortcuts are created by users or the system to provide convenient access. They appear on desktops, in Start menus, and within File Explorer, and are resolved by the shell to locate and launch the target item. A shortcut can point to a local file, a program, a folder, a URL, or a network resource, enabling indirect navigation without exposing the underlying path.

Security and considerations: Because a .lnk file can execute the target or pass command-line arguments, malicious shortcuts are used in phishing and malware campaigns. Unknown or unexpected .lnk files should be treated with caution; antivirus and security software can detect suspicious shell links, and revalidating the target path can reduce risk.

Implementation notes: The format is documented as the Shell Link Binary File Format in Microsoft specifications. Developers can access and manipulate shortcuts via the Windows Shell APIs or via scripting interfaces that expose the underlying COM objects.