These websites threaten to infect your PC with viruses or promise winnings in various competitions.
The fake virus warnings go to a download page that Microsoft classifies as PUA (potentially unwanted application).
How to keep yourself safe from these malvertising attacks?
Still, you are safe as long as you close the respective window without clicking on anything else.
Windows Defender SmartScreen is not recognizing this issue, so it is not blocking it.
In other words, when the fake virus screen appears, you simply close that page or tab. If that page or tab would not close, open Task Manager with Ctrl + Shift + Esc and stop the browser process with End Task.
Also, as a precaution, clear your temporary internet files and cache.
“Win a prize” fake survey: a more complicated issue
As for the “win a prize” fake survey, this issue is more complicated. An user stated:
The “fake survey win a prize ” one is being more problematic in that yes it does go away when you close the tab but unfortunately it keeps coming back. Since I installed Malwarebytes it is blocked but not blocked from trying so whilst I no longer get the” survey” I am getting page blocked interrupting my game about 3 or four time a minute which is frustrating to say the least.
Therefore, basic security and privacy are crucial for eliminating these problems. Choose an antivirus from our list to protect your computer and your privacy.