I had been using Synergy to control my work laptop from my home machine. I hadn't used it in a while (2+ years) and my computer would constantly run out of memory (I think it was in dwm.exe, if I remember correctly) and I would need to reboot. It wasn't until I read the Random ASCII article linked from here (https://randomascii.wordpress.com/2018/02/11/zombie-processe...) about zombie processes that I was able to track it down to Synergy and uninstall it.