I am not a computer scientist, let make that clear and I never pretend to be one. But at least I have the basic understanding of a computer virus.

A computer virus is basically a computer program written to cause harm. This computer virus has the capacity to multiply itself once it gets the chance to infect files on the computer to destroy them.

Viruses have various means and forms of infecting computers.
Basically, this is the work of demons in humans.
Demons get access to a person if the person sins. Whenever we commit sin, we invite demons to possess or influence us. Demons leave persons with nothing but perils, diseases, pain and all the like.

Beloved, let's not take delight in sin, for its wages is death. Let's awash ourselves consistently by walking in the spirit as the bible charges us.

God bless you.

Luke 11:24-26 English Standard Version (ESV)

Return of an Unclean Spirit
24 “When the unclean spirit has gone out of a person, it passes through waterless places seeking rest, and finding none it says, ‘I will return to my house from which I came.’ 25 And when it comes, it finds the house swept and put in order. 26 Then it goes and brings seven other spirits more evil than itself, and they enter and dwell there. And the last state of that person is worse than the first.”