A computer virus is one of thousands of programs that can invade computer systems and perform a variety of functions ranging from annoying (e.g., popping up messages as a joke) to dangerous (e.g., deleting files or destroying your hard disk). Many are harmless but others can be very destructive. Trojan horses or worms are specific types of clandestine programs (loosely categorized as viruses) and can be just as dangerous. For simplicity’s sake, future mention of viruses in this document will refer to viruses, Trojan horses, and worms taken as a whole.
A
computer virus is a malware program
that, when executed, replicates by inserting copies of itself
(possibly modified) into other computer programs,
data files,
or the boot
sector of the hard
drive; when this replication succeeds, the affected areas are then said
to be "infected".[1][2][3][4]
Viruses often perform some type of harmful activity on infected hosts, such as
stealing hard
disk space or CPU
time, accessing private information, corrupting data, displaying political or
humorous messages on the user's screen, spamming their contacts, logging their
keystrokes, or even rendering the computer useless. However, not all viruses
carry a destructive payload or attempt to hide themselves—the defining
characteristic of viruses is that they are self-replicating computer programs
which install themselves without user consent.
Some of
the best-known
viruses include: Love Bug, Melissa, Bubbleboy, Code Red, Nimda.
The following steps can be taken to prevent a
virus infection:
o Protect your computer with strong security software and keep it updated.
o Use a security-conscious Internet service provider (ISP) that implements strong anti-spam and anti-
phishing procedures.
o Enable automatic Windows updates or
download Microsoft updates regularly to keep your operating system patched against known vulnerabilities.
o Use caution when opening attachments.
o Be careful when engaging in
peer-to-peer (P2P) file-sharing.
o Use security precautions for your PDA,
cell
phone, and Wi-Fi devices.
o Configure your instant messaging application correctly.
o Beware of spam-based phishing schemes. Don't click
on links in emails or
IM.
o Back up your files regularly and store the backups somewhere besides your PC.
o Stay aware of current virus news
by checking sites
like
McAfee.