Virus Map

Get a real-time, bird’s-eye view of where the latest viruses are infecting computers worldwide.

Regional Virus Info

Find out which viruses are infecting PCs in your neighborhood and around the world.

Virus Calendar

Be prepared for the next scheduled virus payloads strike with the help of this comprehensive calendar.

Definitions

What is a Virus?
A virus is a manmade program or piece of code that causes an unexpected, usually negative, event. Viruses are often disguised games or images with clever marketing titles such as "Me, nude."

What is a Worm?
Computer Worms are viruses that reside in the active memory of a computer and duplicate themselves. They may send copies of themselves to other computers, such as through email or Internet Relay Chat (IRC).

What is a Trojan Horse?
A Trojan horse program is a malicious program that pretends to be a benign application; a Trojan horse program purposefully does something the user does not expect. Trojans are not viruses since they do not replicate, but Trojan horse programs can be just as destructive.

Many people use the term to refer only to non-replicating malicious programs, thus making a distinction between Trojans and viruses.

Have more questions?
Look up more definitions in our Virus Glossary.