Sara, a user, downloads a keygen to install pirated software. After running the keygen, system
performance is extremely slow and numerous antivirus alerts are displayed. Which of the following BEST
describes this type of malware?

A.
Logic bomb

B.
Worm

C.
Trojan

D.
Adware

Explanation:
In computers, a Trojan is a program in which malicious or harmful code is contained inside apparently
harmless programming or data in such a way that it can get control and do its chosen form of damage,
such as ruining the file allocation table on your hard disk. In one celebrated case, a Trojan was a program
that was supposed to find and destroy computer viruses. A Trojan horse may be widely redistributed as
part of a computer virus.Incorrect Answers:
A: A logic bomb is a piece of code intentionally inserted into a software system that will set off a malicious
function when specified conditions are met. For example, a programmer may hide a piece of code that
starts deleting files should they ever be terminated from the company.
B: A computer worm is a standalone malware computer program that replicates itself in order to spread
to other computers. Often, it uses a computer network to spread itself, relying on security failures on the
target computer to access it. Unlike a computer virus, it does not need to attach itself to an existing
program. Worms almost always cause at least some harm to the network, even if only by consuming
bandwidth, whereas viruses almost always corrupt or modify files on a targeted computer. A computer
worm is not what is described in this question.
D: Adware is free software that is supported by advertisements. Common adware programs are toolbars
that sit on your desktop or work in conjunction with your Web browser. They include features like
advanced searching of the Web or your hard drive and better organization of your bookmarks and
shortcuts. Adware can also be more advanced programs such as games or utilities. They are free to use,
but require you to watch advertisements as long as the programs are open. Since the ads often allow you
to click to a Web site, adware typically requires an active Internet connection to run.
Most adware is safe to use, but some can serve as spyware, gathering information about you from your
hard drive, the Web sites you visit, or your keystrokes. Spyware programs can then send the information
over the Internet to another computer. So be careful what adware you install on your computer. Make
sure it is from a reputable company and read the privacy agreement that comes with it. Adware is not
what is described in this question.

http://searchsecurity.techtarget.com/definition/Trojan-horse
http://en.wikipedia.org/wiki/Logic_bomb
http://techterms.com/definition/adware
http://en.wikipedia.org/wiki/Computer_worm