Question

how can computer get infected with a virus

Answer 1

Any disk, disc, or thumb drive connected or inserted into your computer can be infected with a virus. As long as something is writable, a virus can move from a computer to that disk, disc, or drive. A common tactic used by hackers to gain access to a network is by leaving out a thumb drive with malicious code on it.

Answer 2

Computer can get infected with a virus because whenever we use pen drive or card reader they have viruses so computer gets infected.