"Alert! You have a security problem!" Pop up?

[ImNotReallyHere]

I'm gettign these really annoying pop ups, one says 'Alert! You have a security problem! Do you want to scan your computer for viruses?', it also usually appears with two other full screen pop ups with fake scanners and things, I think they have something like tube-funs-worlds.com and promotion.com/ and something like fghhfhhg.com in the url. ( I no that last one isnt right but the url is just a random bunch of 'f's 'g's and 'h's as far as i no.) I have Malwarebytes' Anti malware and AVG installed but neither is doing anything about it.
What is this and how do i remove it?

thank you xx

[salmank]

boot in safemode by typing F8 when computer starts and scan from safemode.
most of the time this idea resolves most of the virus related problems. Hope your problem is solved