Last year I wrote a piece of software that functions as an accessory application for a large forum software suite. 

Specifically, it is an "Application" for Invision Community.

You can find other similar applications for the same software here: <https://invisioncommunity.com/files/>

I'm unsure how these files are licensed, however I charge $30 + $15/6mo for my application. Recently, an unknown member who purchased it released it on a popular `nulled` software website where people upload paid software packages for free for others to download. Since then, my sales have dropped to nearly $0 for the package.

I'm curious if the licensing of Invision Community leaves much room for me to do anything, or even if it does, if there is really anything I can do about this.