Unsolicited junk email - generally advertising for some product sent wide-scale to a mailing list or newsgroup. There are a number of ways you can find yourself on a spammer's email list, including signing up for newsletters that sell lists of their clients' email addresses, listing your email address on a webpage or newsgroup, or even by choosing an email address that spammers may be able to guess.

Facts About Spam

Spam represents more than 70% of all e-mail traffic.

It is the way to spread viruses.


1) A computer that has been implanted with a daemon that puts it under the control of a malicious hacker without the knowledge of the computer owner. Zombies are used by malicious hackers to launch DoS attacks. The hacker sends commands to the zombie through an open port. On command, the zombie computer sends an enormous amount of packets of useless information to a targeted Web site in order to clog the site's routers and keep legitimate users from gaining access to the site. The traffic sent to the Web site is confusing and therefore the computer receiving the data spends time and resources trying to understand the influx of data that has been transmitted by the zombies. Compared to programs such as viruses or worms that can eradicate or steal information, zombies are relatively benign as they temporarily cripple Web sites by flooding them with information and do not compromise the site's data. Such prominent sites as Yahoo!, Amazon and CNN.com were brought down in 2000 by zombie DoS attacks.

Zombies are also referred to as zombie ants.

(2) In UNIX operating systems, a zombie is a "child" program that was started by a "parent" program but then abandoned by the parent


DoS attack

Short for denial-of-service attack, a type of attack on a network that is designed to bring the network to its knees by flooding it with useless traffic. Many DoS attacks, such as the Ping of Death and Teardrop attacks, exploit limitations in the TCP/IP protocols. For all known DoS attacks, there are software fixes that system administrators can install to limit the damage caused by the attacks. But, like viruses, new DoS attacks are constantly being dreamed up by hackers.



Often unwittingly downloaded programs that enable the delivery of advertising to web users' PCs. Some gather information about the user's internet browsing habits.


Blended threat:

 Combination of viruses, worms, Trojan horses, and malicious code that exploits server and internet vulnerabilities.



Programs installed without a user's knowledge that use a computer's modem to dial out to an expensive toll number.


Keystroke logger:

Program that records individual keystrokes and sends them back to the hacker, who gets user names and passwords.



Program secretly downloaded on to computers to cause damage or steal data.



Malicious activity carried out by a virus.



A variant of phishing that uses bogus e-mails carrying malware programs that can redirect browsers to fake websites even when they type in the correct web address. The customer is then tricked into logging on to their e-mail or bank account and revealing security details to fraudsters.



Sending bogus e-mails reputedly from trusted sources using copycat websites to trick customers into disclosing security information



Computer virus that attacks anti-virus programs in an effort to prevent detection



Hidden programs that scan systems or activity and relay information, including security codes. Commonly hidden in other programs and downloaded unwittingly from freeware websites


Trojan horse:

Program pretending to be legitimate to encourage the user to execute an action. Trojan horses can compromise the security of a computer, allowing a remote user to gain control.



Program or computer code that replicates itself onto other files with which it comes in contact. Harm can range from low-level nuisance to severe system damage.



 Program that makes and facilitates the distribution of copies of itself, for example, via e-mail