Thank you for your post.
Virtually any remote control software can be abused this way. The most obvious course of action would be to send a complaint to the hosting provider where a site or a forum with illegitimate build is hosted.
If the file is distributed on the Stream platform, there must be a user account associated with it, or several accounts. Perhaps, it would be best to send a complaint to the Steam abuse team so that they block the account and take appropriate measures.
It could also help if you sent us the details and specifics, so that we can investigate this issue on our own. You can send the specifics to me via a private message here or to the email firstname.lastname@example.org.