Worms, Trojans, Hackers,& Thieves

Here is a handout I gave out a couple years ago in my computer classes. Hope it helps you understand all the bad boys out there waiting to hijack your computer. Be safe!!

Software: Computer instructions or data. Anything that can be stored electronically is software

Hardware: Refers to objects that you can actually touch, like disks, disk drives, display screens, keyboards, printers, boards, and chips. In contrast, software is untouchable. Software exists as ideas, concepts, and symbols, but it has no substance.

Freeware: Copyrighted software given away for free by the author. Although it is available for free, the author retains the copyright, which means that you cannot do anything with it that is not expressly allowed by the author. Usually, the author allows people to use the software, but not sell it.

Software piracy The unauthorized copying of software. Most retail programs are licensed for use at just one computer site or for use by only one user at any time. By buying the software, you become a licensed user rather than an owner (see EULA). You are allowed to make copies of the program for backup purposes, but it is against the law to give copies to friends and colleagues.

EULA: Short for End-User License Agreement, the type of license used for most software. An EULA is a legal contract between the manufacturer and/or the author and the end user of an application. The EULA details how the software can and cannot be used and any restrictions that the manufacturer imposes (e.g., most Eula's of proprietary software prohibit the user from sharing the software with anyone else).

Shareware: Software distributed on the basis of an honor system. Most shareware is delivered free of charge, but the author usually requests that you pay a small fee if you like the program and use it regularly. You can copy shareware and pass it along to friends and colleagues, but they too are expected to pay a fee if they use the product

Nagware: Software or programming that routinely issues a pop-up window or other form of visual interface asking the user to register a product, purchase an application or take another form of action.

Virus: A program or piece of code that is loaded onto your computer without your knowledge and runs against your wishes. Viruses can also replicate themselves. All computer viruses are manmade. A simple virus that can make a copy of itself over and over again is relatively easy to produce. Even such a simple virus is dangerous because it will quickly use all available memory and bring the system to a halt.

Worm: A worm is a special type of virus that can replicate itself and use memory, but cannot attach itself to other programs.

Trojan horse: a destructive program that masquerades as a benign application. Unlike viruses, Trojan horses do not replicate themselves but they can be just as destructive. One of the most insidious types of Trojan is a program that claims to rid your computer of viruses but instead introduces viruses onto your PC.

Spyware: Any software that covertly gathers user information through the user's Internet connection without his or her knowledge, usually for advertising purposes. Spyware applications are typically bundled as a hidden component of freeware or shareware programs that can be downloaded from the Internet.

Adware: A form of spyware that collects information about the user in order to display advertisements in the Web browser based on the information it collects from the user's browsing patterns.

Malware. Short for mal icious software, software designed specifically to damage or disrupt a system, such as a virus or a trojan horse.

Anti-virus program: A utility that searches a hard disk for viruses and removes any that are found. Most antivirus programs include an auto-update feature that enables the program to download profiles of new viruses so that it can check for the new viruses as soon as they are discovered.

Virus signature: A unique string of bits, or the binary pattern, of a virus. The virus signature is like a fingerprint in that it can be used to detect and identify specific viruses. Anti-virus software uses the virus signature to scan for the presence of malicious code. Sometimes called a dat file or Virus definition.