A computer virus is a form of malicious software that piggybacks onto legitimate application code in order to spread and reproduce itself.

From macro viruses and boot sector viruses to droppers and packers, here’s a look at 9 common virus types, what they do, and the function they perform for attackers.

How's this for authenticity? "Cybergeddon," the new online series from "CSI" creator Anthony E. Zuiker, will show lines of actual hacker code for creating computer viruses.

(IDG) -- Virus: A self-replicating piece of computer code that can partially or fully attach itself to files or applications, and can cause your computer to do something you don't want it to do ...

How's this for authenticity? "Cybergeddon," the new online series from "CSI" creator Anthony E. Zuiker, will show lines of actual hacker code for creating computer viruses. The code will come ...

Viruses have been known to cause system changes that affect external hardware and accessories. Computer operating by itself Computers should not be executing demands without authorisation.

WASHINGTON-- After infecting 225,000 business and institutional computer systems and nearly toppling the White House Web site, an insidious computer virus called Code Red spawned a new variation ...

Now computer scientists have done the same with software, demonstrating the potential for hard-to-detect viruses that are stitched together from benign code pilfered from ordinary programs.

Machine code inserted into all email attachments could prevent even the newest viruses from delivering their payloads ...