Melissa is a virus that exploits the macro feature within the Microsoft Office suite in order to infect documents and mass mail copies of itself to a victims address book. Unlike viruses that are packaged as stand-alone executable files, Melissa uses a feature that allows Office documents to activate other Microsoft applications and use their abilities.

A Botnet, or robot network, is a term used to describe a collection of computers that have been compromised by a worm or Trojan horse that allows an attacker to remotely control the systems.

If you have a virus you can not delete or if your system will not boot up correctly and you suspect a virus is the problem, a recommended solution is to start your computer in safe mode and run a virus scan. To run a virus scan in safe mode, follow these steps:

While it is true that there was a virus that appeared in the summer of 2007 with a subject line of, “You’ve received a postcard from a family member,” as well as several other variations of the subject line that talked about a “card” or a “greeting card,” these viruses had nothing to do with this false warning about “A card for you” or “A virtual card for you.”

A virus definition (also known as a virus signature) is a unique string of bits, or the binary pattern, of the machine code of a virus. The term virus definitions typically refers to the database of all current virus signature files used by a particular anti virus software for virus detection. Virus definitions are the primary method of detection for most anti virus software programs.

Rootkits refer to the cloaking techniques and methods that, when combined with Trojans, allow attackers undetectable remote administrative access. Their concealment strategies involve modifying system code and processes that would normally detect or prevent remote access. Rootkits alter basic system functions and foundations in order to disguise unauthorized activity.

Computer Worms wreak havoc by exploiting security loopholes and flaws in software design to propagate from one machine to another. Worms are different than a traditional virus in that they don’t spread by modifying programs on a single system, but rather by searching for and implanting destructive code onto other systems.

Computer Viruses are computer programs that adversely affect other programs by modifying them in such a way as to include copies of their destructive code. When infected files are run, implanted code will be executed which searches out and infects other executable files.

Keystroke logging, or keylogging, refers to the process of capturing and recording users computer keystrokes without their express consent. The most threatening keyloggers allow an attacker to remotely monitor victim’s recorded keystrokes.

W32 is commonly used as the prefix for many variants of viruses and worms that exploit vulnerabilities in the 32-bit versions of Microsoft Windows. The majority of W32 viruses and worms are spread online through network services including email, web sites, file sharing systems, and instant messages. Therefore, any computer connected to the Internet runs the risk of of being infected with a W32 virus.