[cheap]

Your Chrome browser has been hijacked.

The best way I have found to fix this is

1) delete all cache and cookies
2) uninstall chrome
3) reinstall Chrome

The Adblock extension will not fix this and it is suspected the hijacking is happening through an extension (quite possibly Adblock). Lots of hits on Google, Google recognize the problem and have a "reset" back to basic configuration, however this doesn't fix the problem. S&D or other malware killers do not find the culprit.

I use Chrome and I think it leaves a lot to be desired, which might give you an indication of how bad I think the other browsers are.