heroui logo

Suspicious LNK Double Extension File Created

Sigma Rules

View Source
Summary
This detection rule identifies the creation of files with a second extension of ".lnk", which is typically associated with shortcuts in Windows. This behavior is often leveraged by malicious actors as a method to disguise harmful files by exploiting the default setting in Windows that hides known file extensions, including ".lnk". The rule looks for files that end with the ".lnk" extension, particularly in combination with other common document and media extensions such as ".doc", ".jpg", and ".pdf". It specifically checks the directory path of previously accessed files within the user's recent files folder and also considers the execution context of common Office applications like Word, Excel, and PowerPoint. The goal is to detect any suspicious activity that may indicate an attempt to execute a malicious payload disguised as a harmless document or media file.
Categories
  • Windows
  • Endpoint
  • Infrastructure
Data Sources
  • File
Created: 2022-11-07