Well if your 'random' updates are because Windows/Chrome are set to install available updates automatically that's probably a good thing, from a security perspective.
I'm not on Windows so can't really check if Google have decided to include some kind of adblocking by default, but to me that sounds unlikely as, currently, Chrome add-on developers are up in arms about changes to the APIs available to them that will make it harder for add-blockers to work (for example , ) which Google are justifying (trying to justify, but no-one is buying it) under the label of "security".
Are you saying that you have a Chrome add-on installed that's called "adblocker", or you've got the "adblock plus" add-on installed?
I know that "adblock plus" used to have a setting about allowing whitelisted adds, so there could be something in the settings there that you could tweak. But, randomly acquiring browser add-ons doesn't sound too good in the first place, does it?
The installed add-ons, and their origins are able to be listed within the browser. Maybe updating/running the anti virus is a good idea you truly have randomly got a third-party add-on installed?