A virus is a computer programs that can “self replicate” or copies itself and spreads from one machine to another. Typically, a virus is a small piece of software that piggybacks on real programs. For example, a virus might attach itself to a program like Word. Each time Word runs, the virus runs too.
An email virus moves around in email messages, and usually will replicate itself by automatically mailing itself to dozens of people in the victim’s email address book.
A worm is a small piece of software that uses computer networks and security holes to replicate itself. A copy of the worm scans the network for another machine that has a specific security hole. It copies itself to the new machine using the security hole, and then starts replicating itself.
A Trojan horse is simply a normal computer program. The program is intended to damage only one computer. They do not spread to other files on a computer. A Trojan horse is simply a program with a single destructive payload. This might range from deleting a user’s hard drive to emailing sensitive information from a target computer back to the virus. A Trojan horse may also be used as a "remote control." This remote control allows the writer of the program to control the infected computer over the Internet.
The typical coder of a virus is an 18- to 24-year-old male. They are usually smart and want to buck the system.
Viruses can be spread via floppy disks or CDs, email attachments, or in material downloaded from the Web, although the majority of viruses are spread through email. When the attachment is opened, the virus is activated and the computer becomes infected.
Often, viruses are programmed to spread themselves by emailing a copy of the attachment to all the other email addresses in an infected computer’s address book.
The best way to avoid getting a computer virus is never to open attachments. If you must open an attachment, contact the person who sent you the attachment to make sure they sent it. Also, check the type of file before attachment before opening it. Attachments that end with the .vbs extension or the .exe extension are the most dangerous.
Antivirus software keeps a database of “fingerprints”—a set of characteristics bytes from known viruses—on file. It searches the files and programs on your computer for that pattern, and when it finds a fingerprint it recognizes as belonging to a virus, the antivirus software notifies the user that the virus is present.
If you think your computer may have a virus, the first thing you should do is run an up-to-date virus scan. Once you have targeted the virus, please call the Help Desk we will arrange to have a field technician remove the virus.
The most common viruses work through email, particularly Outlook Express. Other types of viruses infect the macro templates in Microsoft Word and Excel documents.
Viruses are computer programs, and they can do anything that a normal program can do. This includes deleting files, formatting a user’s hard drive, and even overwriting the BIOS, completely disabling the computer.
If you suspect you have a virus or have questions about viruses, please call the ITS ServiceDesk at x3275.