The most common source of computer viruses comes from surfing the web for porno. Everyone says they don’t do it, but if 90% of the sites on the internet are 
XXX, then someone has to be a porno addict.
And unfortunately as Gore Vidal stated, “The watching of pornography only leads to the watching of more pornography.”
Viruses come from exterior web companies wanting to ream your computer for information, load spyware to survey your viewing practices, and also piggyback trojan programs to exploit your computer for hard drive use. Bible thumpers also slip in viruses to certain sites to punish your indecent deeds and thoughts. Sex is only for making babies.
Porno sites screw you, if you don’t download their material. I personally love the 20 second clips. Almost like eating stolen potato chips.
But the worse threat comes from good old Microsoft.
Never respond to an update command from the world’s biggest company.
They will check your system for bootleg software and shut it down
Lastly never open emails from email addresses you don’t recognize.
Never.
I would like to ban you from porn surfing, but where there are waves surfers will ride.