Shortcut Modification

What the technique is

Adversaries may create or modify shortcuts that can execute a program during system boot or user login. Shortcuts or symbolic links are used to reference other files or programs that will be opened or executed when the shortcut is clicked or executed by a system startup process. Adversaries may abuse shortcuts in the startup folder to execute their tools and achieve persistence. Although often used as payloads in an infection chain (e.g. Spearphishing Attachment), adversaries may also create a new shortcut as a means of indirection, while also abusing Masquerading to make the malicious shortcut appear as a legitimate program. Adversaries can also edit the target path or entirely replace an existing shortcut so their malware will be executed instead of the intended legitimate program. Shortcuts can also be abused to establish persistence by implementing other methods. For example, LNK browser extensions may be modified (e.g. Browser Extensions) to persistently launch malware.

What MITRE says you would watch

• AN0510

  Detection correlates file creation or modification of.lnk (shortcut) files in autostart locations with anomalous parent-child process lineage or unsigned binaries. Defenders should watch for LNK creation/modification events outside of known software installations, patch events, or OS updates. Flag shortcut targets pointing to suspicious locations or unknown binaries, particularly those written by script interpreters or spawned from phishing delivery chains.