Virus Information System

Description of Virus Information System

Viruses comprise one class of a wide variety of malicious software known collectively as "malware". A computer virus takes advantage of the resources available on an infected system to do some or all of the following: to propagate itself via removable media (e.g., USB sticks, CD, DVD), email, or network connections; to destroy data; and possibly to embarrass the owner of the system by redistributing documents found on the victim system's hard drive or mailboxes. A computer virus cannot run on its own: the program must be executed in order to take effect. However, viruses can be written to take advantage of a particular program or operating system's features or security vulnerabilities so as to make it more likely that they will be inadvertently run. Once run, a virus may make modifications to system files so that the virus continues to be run every time the computer is restarted, or every time a particular program (such as an email client) is used. Some Viruses only cause minor problems, while other viruses can permanently destroy data. Most viruses include some mechanism for persisting on the infected computer and for propagating themselves to other computers. The propagation methods include transmission via network connections, as emailed attachments or additions to shared files, or even simply writing themselves to removable media, where they will attempt to infect the next computer to access the media. Often a user will learn that his or her own system is infected only when a friend or colleague complains about a strange email message or other odd behavior coming from the user's computer. At Caltech, you may learn that a computer is infected because Information Security detected it engaging in suspicious activity.