It seems that
no sooner do you feel safe turning on your computer
than you hear on the news about a new kind of internet
security threat. Usually, the security threat
is some kind of malware (though the term "security threat"
no doubt sells more newspapers).
What is malware? Malware is exactly what its name
implies: mal (meaning bad, in the sense of malignant
or malicious rather than just poorly done) + ware (short
for software). More specifically, malware is software
that does not benefit the computer's owner, and may
even harm it, and so is purely parasitic.</p>
The Many Faces of Malware
According to Wikipedia, there are in fact eleven distinct
types of malware, and even more sub-types of each.
1. Viruses. The malware that's on the news so
much, even your grandmother knows what it is.
You probably already have heard plenty about why this
kind of software is bad for you, so there's no need
to belabor the point.
2. Worms. Slight variation on viruses.
The difference between viruses and worms is that viruses
hide inside the files of real computer programs (for
instance, the macros in Word or the VBScript in many
other Microsoft applications), while worms do not infect
a file or program, but rather stand on their own.
3. Wabbits. Be honest: had you ever even heard
of wabbits before (outside of Warner Bros. cartoons)?
According to Wikipedia, wabbits are in fact rare, and
it's not hard to see why: they don't do anything to
spread to other machines. A wabbit, like a virus,
replicates itself, but it does not have any instructions
to email itself or pass itself through a computer network
in order to infect other machines. The least ambitious
of all malware, it is content simply to focus on utterly
devastating a single machine.
4. Trojans. Arguably the most dangerous kind
of malware, at least from a social standpoint.
While Trojans rarely destroy computers or even files,
that's only because they have bigger targets: your financial
information, your computer's system resources, and sometimes
even massive denial-of-service attacks launched by having
thousands of computers all try to connect to a web server
at the same time. Trojans can even
5. Spyware. In another instance of creative software
naming, spyware is software that spies on you, often
tracking your internet activities in order to serve
you advertising. (Yes, it's possible to be both
adware and spyware at the same time.)
6. Backdoors. Backdoors are much the same as
Trojans or worms, except that they do something different:
they open a "backdoor" onto a computer, providing a
network connection for hackers or other malware to enter
or for viruses or spam to be sent out through.
7. Exploits. Exploits attack specific security
vulnerabilities. You know how Microsoft is always
announcing new updates for its operating system?
Often enough the updates are really trying to close
the security hole targeted in a newly discovered exploit.
8. Rootkit. The malware most likely to have a
human touch, rootkits are installed by crackers (bad
hackers) on other people's computers. The rootkit
is designed to camouflage itself in a system's core
processes so as to go undetected. It is the hardest
of all malware to detect and therefore to remove; many
experts recommend completely wiping your hard drive
and reinstalling everything fresh.
9. Keyloggers. No prize for guessing what this
software does: yes, it logs your keystrokes, i.e., what
you type. Typically, the malware kind of keyloggers
(as opposed to keyloggers deliberately installed by
their owners to use in diagnosis computer problems)
are out to log sensitive information such as passwords
and financial details.
10. Dialers. Dialers dial telephone numbers via
your computer's modem. Like keyloggers, they're
only malware if you don't want them. Dialers either
dial expensive premium-rate telephone numbers, often
located in small countries far from the host computer;
or, they dial a hacker's machine to transmit stolen
data.
11. URL injectors. This software "injects" a
given URL in place of certain URLs when you try to visit
them in your browser. Usually, the injected URL
is an affiliate link to the target URL. An affiliate
link is a special link used to track the traffic an
affiliate (advertiser) has sent to the original website,
so that the original website can pay commissions on
any sales from that traffic.
12. Adware. The least dangerous and most lucrative
malware (lucrative for its distributors, that is).
Adware displays ads on your computer. The Wikipedia
entry on malware does not give adware its own category
even though adware is commonly called malware.
As Wikipedia notes, adware is often a subset of spyware.
The implication is that if the user chooses to allow
adware on his or her machine, it's not really malware,
which is the defense that most adware companies take.
In reality, however, the choice to install adware is
usually a legal farce involving placing a mention of
the adware somewhere in the installation materials,
and often only in the licensing agreement, which hardly
anyone reads.
Are you ready to take on this dirty dozen? Don't
go it alone. Make sure you have at least one each
of antivirus and antispyware software on your computer
right now.
About
the author: Joel Walsh writes for spyware-refuge.com
about malware removal: http://www.spyware-refuge.com/spyware-removal.html?%20malware%20remover |
