In whatever browser I’ve used except for avast safezone, a new tab keeps popping up for a site called “appimat” or something, saying that “There is a new codec pack version” and won’t let me close it or go back to any other tab or close the browser unless I click the link or kill the process. This appimat thing is the most common one but I’ve had others. Malwarebytes and avast have found nothing, I haven’t installed anything suspicious, and this only started about an hour ago. On my other computer, I keep getting popups for something like cpv LLC. What’s going on here?
You have in all probability a browser infection
http://forum.avast.com/index.php?topic=53253.0 follow the steps here