Adblock via /etc/hosts
I had been doing this until some time ago to block ads and to prevent Google from collecting my web browsing history via Google Analytics. During the time I witnessed a strange phenomenon. Every time I added  "127.0.0.1 www.google-analytics.com" to C:\Windows\System32\Drivers\etc\hosts. I saw the line removed from the file some hours later. Although I had added tens of lines I only saw the Google Analytics line removed. IIRC finally I decided to figure out whet caused the removal. I used Filemon to watch file changes, though the line got removed again while watching the file and nothing appeared on the log. I suspected Ring-0 processes were secretly running and causing the removal, but I knew nothing about the Windows kernel so I gave up here. I wonder what was the cause to this day.