Virus hack attempt

The only way to do that is to have premium membership (which is a !! move)

Nope, AdBlock (a Firefox add-on) does the job. However, you're not supporting chess.com that way.

I'm running Ubuntu so I'm not particularly worried about viruses, but reading all these posts makes me consider getting AdBlock again (which I had on my Windows OS for security reasons).

I can't afford a membership, so it's only fair if chess.com gets at least the ad revenue, but I will not compromise the safety of my computer (though again, Ubuntu tends to be very safe).

There are many trojans nowadays that are not visible for main firewalls, especially encrypting viruses, that ensort money for decryption. recently noticed one interesting Japanese source http://sakujosuru.jp/guides/vvv-file that claim to identify this thread and disarm.