ARCHIVED: Avoiding computer viruses
Computer viruses implant instructions in other programs or storage devices and can attack, scramble, or erase computer data. The danger of computer viruses lies in their ability to replicate themselves and spread from system to system. Few computing systems are immune to infection.
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The following activities are among the most common ways of getting computer viruses. Minimizing the frequency of these activities will reduce your risk of getting a computer virus:
- Freely sharing computer programs and system disks, or downloading
files and software through file-sharing applications such as
BitTorrent, eDonkey, and KaZaA
- Clicking links in instant messaging (IM) that have no
context or have only general text; for more information, see What should I do if my computer is infected with an instant messaging (IM) Trojan?
- Downloading executable software from public-access bulletin boards
or web sites
- Using your personal disk space with public computers or other
computers that are used by more than one person
- Opening email attachments from people you don't know or without
first scanning them for viruses; for more information, see ARCHIVED: Using Symantec/Norton AntiVirus Corporate Edition, how do I immediately scan a file, folder, or drive for viruses? and ARCHIVED: Using Norton AntiVirus for Mac OS or Mac OS X, how do I immediately scan a file, folder, or drive for viruses?
- Opening any email attachment that ends in
.lnkon a computer running Microsoft Windows (At Indiana University, UITS blocks certain attachments that commonly harbor viruses from being delivered via email; for more information, see At IU, what types of attachments are blocked from my email account?)
- Continually running your Windows computer as an administrator; for more information, see ARCHIVED: In Windows, why should I avoid running my computer as an administrator?
How to avoid computer viruses
Following are some recommendations for safe computing:
- The most important thing you can do to keep your computer safe is
to install virus detection software and keep the virus patterns up to
date. Antivirus programs perform two general functions: scanning for
and removing viruses in files on disks, and monitoring the operation
of your computer for virus-like activity (either known actions of
specific viruses or general suspicious activity). Most antivirus
packages contain routines that can perform each kind of task.
Note: The University Information Security Office (UISO) recommends that you run the latest version of Symantec virus protection software (available to IU students, faculty, and staff free of charge via IUware) for your operating system; See In Windows, how do I safely upgrade to the latest security software? Be sure to upgrade safely, update your virus definitions daily, and scan your computer weekly. Check the software help for instructions.
- Keep your operating system current with the latest
patches and updates. The writers of viruses and
worms often exploit bugs and security holes in operating
systems and other computer software. Software manufacturers frequently
release patches for such holes. For information on obtaining the
latest patches, see ARCHIVED: For Windows, how can I get software updates and patches? and ARCHIVED: For Mac OS X, how do I obtain and install system software updates?
- Back up your files. Viruses are one more very good reason to
always back up your files.
Note: If you back up a file that is already infected with a virus, you can re-infect your system by restoring files from the backup copies. Check your backup files with virus scanning software before using them.
- Keep your original application and system disks locked
(write-protected). This will prevent the virus from spreading to your
- If you must insert one of your application disks into an unknown
computer, lock (write-protect) it first, and unlock your application
disk only after verifying that the machine is virus-free.
- Obtain public-domain software from reputable sources. Check newly
downloaded software thoroughly using reputable virus detection
software on a locked floppy disk for any signs of infection before you
copy it to a hard disk. This can also help protect you from
Trojan horse programs.
- Quarantine infected systems. If you discover that a system is
infected with a virus, immediately isolate it from other systems. In
other words, disconnect it from any network it is on and don't allow
anyone to move files from it to another system. Once the system has
been disinfected, you can copy or move files.
- If you use a desktop version of Outlook, minimize use of the preview or reading pane feature.
Last modified on August 30, 2010.