Problem in Facebook account.?

[Mico]

You probably have an adware in your computer.
As to how you got it, we do not know unless you provide more information.

For now, do a full scan of your computer using your Anti-Virus (supposing you have any). If nothing comes up, try booting into safe mode and login to Facebook, see if the advertisements still pops out. If it does, then probably it has something to do with your browser. Try changing browsers, or at least clear all cookies and cache.

If all else fail, a full format would be suggested, but that's the last thing you should do though.