Patrick was active developing software back then, and was quick to find the responsible DLL file that downloaded the ads. Removing the file caused the software to display errors, so he wrote a replacement file that would accept commands from the software, but not do anything at all.
Since the file came back after an update, he decided to have the most simple program, basically just a window with a button, to find and replace this file without the hassle of having to do it manually again.
Over the next month, more software started to using adware, so the software soon had a list of a few dozen entries to check, and a list to display results.