Trojan.LNK.Gen

Classification

Malware

Trojan

W32

Trojan.LNK.[family], Trojan.LNK.Gen, Trojan:W32/LnkGen

Summary

Trojan.LNK.Gen is a generic detection for maliciously modified shortcut files (file extension .LNK) that are designed to trick users into launching a harmful file.

Security programs use generic detections that look for broad patterns of code or behavior to identify similar programs or files. If you suspect the file was incorrectly detected, go to: Removal: Resolving a False Positive.

Removal

Automatic action

Based on the settings of your F-Secure security product, it will either move the file to the quarantine where it cannot spread or cause harm, or remove it.

Resolving a False Positive

A False Positive is when a file is incorrectly detected as harmful, usually because its code or behavior resembles known harmful programs. A False Positive will usually be fixed in a subsequent database update without any action needed on your part. If you wish, you may also:

  • Check for the latest database updates

    First check if your F-Secure security program is using the latest detection database updates, then try scanning the file again.

  • Submit a sample

    After checking, if you still believe the file is incorrectly detected, you can submit a sample of it to F-Secure Labs for re-analysis.

    NOTE If the file was moved to quarantine, you need to collect the file from quarantine before you can submit it.

  • Exclude a file from further scanning

    If you are certain that the file is safe and want to continue using it, you can exclude it from further scanning by the F-Secure security product.

    Note You need administrative rights to change the settings.

Find out more

Knowledge Base

Find the latest advice in our Community Knowledge Base.

User Guide

See the user guide for your product on the Help Center.

Contact Support

Chat with or call an expert for help.

Submit a sample

Submit a file or URL for further analysis.

Technical Details

LNK files are shortcut files that display an icon on the computer Desktop or in a folder, and act as a direct link to a specified folder, file or system location. Shortcuts are used to make finding specific files or system locations much more convenient for the user.

Attackers however can modify shortcut files, or drop specially-crafted ones, that point to harmful files or components that have been silently installed on the system. When the user clicks on the 'booby-trapped' shortcut, they unintentionally launch the harmful file.

Harmful LNK files will usually mimic legitimate ones by using the file icons associated with popular programs such as Notepad, Word, PDF, etc to trick the user into thinking that the shortcuts are authentic.

How they spread

Some malware will install harmful LNK files as part of their payload.

Harmful LNK files are also often spread in infected removable drives; in such cases, the harmful files they link to are hidden on the removable drive, while the LNK file is visible.

Impact

Based on the specific malware, clicking the shortcut can result in various actions. Some malware show no obvious actions after the shortcut is clicked, but will silently run malicious components in the background. Other will open a legitimate program (for example Word or Notepad) to distract the user, while still silently launching other components in the background.

Some LNK malware will also open the command prompt (cmd.exe) and execute malicious scripts in the background, so that several different malicious routines can run at the same time. Examples of such scripts include:

  • c start crack.vbs & start explorer ASA & exit
  • c start ..\Skypee\AutoIt3.exe /AutoIt3ExecuteScript ..\Skypee\googleupdate.a3x explorer "%CD%" & exit
  • c start COOL.vbs & start document.doc & exit

Other

The Trojan.LNK.Gen generic detection can also be triggered by LNK components used by malware families, particularly those that are written in the AutoIT or VBS languages, such as:

This detection will also identify malware executed from a shell and in some cases, will identify malware that contain specific parameters or instructions.

Date Created:

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