I recently noticed how when I started up Firefox, my homepage url was displaying as "https://www.google.com/?bcutc=sp-004-752" instead of "https://www.google.com." I was able to change it back manually, but am curious as to why it changed. I tried asking on the Mozilla forums, but mainly got suggestions to run virus and malware scans or questions about if I had run any installers. Every scan I've run (Malwarebytes, Adwcleaner, eset, etc.) says I'm clean and the last time I installed anything was when I reinstalled Avast. Does anyone here know what's going on?