How does a computer virus enter the PC?

How does a computer virus enter the PC?

A computer virus always needs a "host file" in order to infect a computer. This is why computer viruses are transmitted to computers via attachments to e-mails or via downloads from websites. As soon as the infected file has been opened, the malware copies itself to other files, can spread and execute the malicious code.

Viruses can also be spread using a Trojan horse.