Viruses

Viruses are a class of malware that take advantage of the resources available on an infected system to propagate via removable media (e.g., USB sticks), email, or network connections. A 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 is used.

Virus can steal information or permanently destroy data. Most viruses include some mechanism for persisting on the infected computer and for propagating themselves to other computers. 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.

Protecting your computer from viruses

Employ antivirus software
Recent versions of Windows include built-in antivirus software. Caltech users can also access free antivirus software through the site-licensed software store at http://software.caltech.edu. It is important to note that no antivirus software can be completely effective in protecting your system from threats. Even if you are running antivirus software, you should still follow safe computing practices and routinely backup important data.

Keep software up to date
Malicious software often takes advantage of security flaws in common programs and operating systems. These flaws are routinely discovered and fixed in updates. To make sure your devices stay protected, keep the programs you use and the operating systems on your devices up to date when new updates become available. In particular, keep antivirus software up to date. Whenever possible, configure your operating system and antivirus software to update automatically.

Make regular backups of your data
A virus could potential destroy important data. Ensure that reliable and ongoing backups of all important data are in place. Caltech has a site license for CrashPlan, a cloud-based backup service. For more information about backing up data see Backup Guidelines.

Be careful about downloads and email attachments
Don't download files or open email attachments if you don't understand and trust the source of these files. For more information see secure web browsing.

Don't connect untrusted removable media
Viruses can spread by removable media such as USB sticks. In some cases, viruses can run automatically and infect your computer when the media is connected. Only use trusted removable media.

Dealing with a virus infection

Immediately power off the infected system
Power the system off completely and leave it off until you can get assistance.

Contact IMSS for help
Send an email to security@caltech.edu or call the Help Desk at x3500 or 626-395-3500 during business hours.