This site often opens in pop-ups and displays fake system/browser notifications, and tries to install browser extensions as well. Of course, if one visits it on their own, it'll redirect to some Polish site.

notorious on YouTube, are long gone. However, the domain is still owned by unknown folks. Currently it seems to either be a blank site or contain random ads.

Fake Flash Player update site. The downloaded file is Adware.YoBrowser

A well-known Slovenian blog.

advertised through spam Wordpress comments. Probably a scam.