Virus and a Worm

Difference between a Virus and a Worm?

“Virus” has become a generic term that includes all the malicious ways your computer can be attacked.   

Viruses are distributed by making copies of themselves or replication.   

Sometimes the replication itself causes damage to your hard disk.  Sometimes the accumulative effect of replicating again and again disables the computer. 

A Virus is a program that piggy-backs on other programs. It can be attached to a Word or Excel file.  Each time the file is run, the virus runs too.  It attaches itself to other programs and continues to reproduce.

An Email virus is a special type of virus sent as an attachment to an email message.  It replicates by automatically mailing itself to everyone in the recipients email address book.  

A Worm uses computer networks to replicate itself.  It searches for servers with security holes and copies itself there.  It then begins the search and replication process again.

A Trojan Horse is a computer program masquerading as a game or a “cute” program.  However, when it runs it does something else - like erasing your hard drive or blocking your screen with a graphic will not go away.

Some viruses use several of these in combination to replicate themselves