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In the past
few years the threats from malicious software and hackers
have increased exponentially. More ominously, today it is not only your computer
and files under attack, but your very identity. There was a time when you could
easily protect yourself by installing an anti-virus program, but now you need a
balanced set of tools.
Computer Service Professionals can perform a comprehensive examination of your
system and recommend the right tools specifically designed for you.
The following is a set of basic questions about these threats. |
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What is a virus?
•
What
is a worm?
•
What is a Trojan?
• How do I know if I have a virus?
• What is Spyware? |
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| Q: |
WHAT
IS A VIRUS? |
| A: |
A computer virus is a program
– a piece of executable code – that has the unique ability to replicate.
Like biological viruses, computer viruses can spread quickly and are often difficult
to eradicate. They can attach themselves to just about any type of file and are
spread as files that are copied and sent from individual to individual.
In addition to replication, some computer viruses share another commonality: a
damage routine that delivers the virus payload. While payloads may only display
messages or images, they can also destroy files, reformat your hard drive, or
cause other damage. If the virus does not contain a damage routine, it can cause
trouble by consuming storage space and memory, and degrading the overall performance
of your computer.
Several years ago most viruses spread primarily via floppy disk, but the Internet
has introduced new virus distribution mechanisms. With email now used as an essential
business communication tool, viruses are spreading faster than ever. Viruses attached
to email messages can infect an entire enterprise in a matter of minutes, costing
companies millions of dollars annually in lost productivity and clean-up expenses.
Viruses won't go away anytime soon: More than 60,000 have been identified, and
400 new ones are created every month, according to the International Computer
Security Association (ICSA). With numbers like this, it's safe to say that most
organizations will regularly encounter virus outbreaks. No one who uses computers
is immune to viruses. |
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| Q: |
WHAT
IS A WORM? |
| A: |
A worm is a computer program
that has the ability to copy itself from machine to machine. Worms normally move
around and infect other machines through computer networks. Using a network, a
worm can expand from a single copy incredibly quickly. For example, the Code Red
worm replicated itself over 250,000 times in approximately nine hours on July
19, 2001. A worm usually exploits some sort of security hole in a piece of software
or the operating system. For example, the Slammer worm (which caused mayhem in
January 2003) exploited a hole in Microsoft's SQL server.
Worms use up computer time and network bandwidth when they are replicating, and
they often have some sort of evil intent. A worm called Code Red made huge headlines
in 2001. Experts predicted that this worm could clog the Internet so effectively
that things would completely grind to a halt.
The Code Red worm slowed down Internet traffic when it began to replicate itself,
but not nearly as badly as predicted. Each copy of the worm scanned the Internet
for Windows NT or Windows 2000 servers that do not have the Microsoft security
patch installed. Each time it found an unsecured server, the worm copied itself
to that server. The new copy then scanned for other servers to infect. Depending
on the number of unsecured servers, a worm could conceivably create hundreds of
thousands of copies. |
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| Q: |
WHAT
IS A TROJAN? |
| A: |
A Trojan is a piece of code
that performs unexpected or unauthorized, often malicious, actions. The main difference
between a Trojan and a virus is the inability to replicate. Trojans cause damage,
unexpected system behavior, and compromise the security of systems, but do not
replicate. If it replicates, then it should be classified as a virus.
A Trojan, coined from Greek mythology's Trojan horse, typically comes in good
packaging but has some hidden malicious intent within its code. When a Trojan
is executed users will likely experience unwanted system problems in operation,
and sometimes loss of valuable data. |
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| Q: |
HOW
DO I KNOW IF I HAVE A VIRUS? |
| A: |
You must remember that there
are very many things that can go wrong with your computer and a virus is not always
to blame.
The only way you can know whether or not your computer is infected is by scanning
your machine with an up to date anti-virus program. |
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