Computer
virus
Computer viruses
are small software programs that are designed to spread from one computer to
another and to interfere with computer operation. A virus might corrupt or delete data on your
computer, use your e-mail program to spread itself to other computers, or even
erase everything on your hard disk. 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. Computer viruses currently
cause billions of dollars worth of economic damage each year, due to causing
systems failure, wasting computer resources, corrupting data, increasing
maintenance costs, etc. Viruses are most easily spread by attachments in
e-mail messages or instant messaging messages. Viruses also spread through
downloads on the Internet. They can be hidden in illicit software or other
files or programs you might download.
Malware (for "malicious software") is
any program or file that is harmful to a computer user "Malware"
is a term for any software that gets installed on your machine and performs
unwanted tasks, often for some third party's benefit. Malware programs can range
from being simple pop-up advertising to causing serious computer invasion and
damage (e.g., stealing passwords and data or infecting other machines on the
network). Some malware provides no uninstall option, and installs code in
unexpected and hidden places (e.g., the Windows registry) or modifies the
operating system, thus making it more difficult to remove.
Trojan Horse
A program written to deliver a malicious program
that may then cause destruction to your computer. A Trojan horse is
delivered by someone or hidden within another program that may seem harmless.
Spyware
A program written to monitor your actions on a
computer. A common type of spyware is a key-logger program. This
program can record every key stroke and mouse click you make. Spyware can
be delivered via a Trojan horse program.
Adware
Adware
is a form of malware. One word - pop-ups. Adware is designed to pop
up advertisements. Adware can be very annoying.