Trojans, Viruses, and Worms, Oh My!
Adware: a program that generates popups on your computer or displays advertisements. Not all adware programs are necessarily considered malware, or harmful. There are many legitimate programs that are given for free that display ads in their programs in order to generate revenue. If the information is provided up front they are not considered malware.
Hijackers: Are programs that attempt to hijack certain Internet functions like redirecting your start page to the hijacker's own start page, redirecting search queries to a undesired search engine, or replace search results from popular search engines with their own information.
Keyloggers: Are programs that will run without user knowledge and monitor keyboard input. Such information is normally send back to the creator and used to grant access to personal accounts such as email, facebook, and even banking.
Lockout Virus: Are infections that will disable a computer and render them useless. Lockout viruses will disable all programs from running and normally display a blank screen. This infection tends to wait for a reboot of the computer to lock a user out of the system, where all that will be displayed is the users background or a blue/black screen. User account issues such as crippling permissions to necessary files can also occur.
Malware: Programming or files that are developed for the purpose of doing harm. It includes, computer viruses, worms, trojan horses, spyware, keyloggers, and rootkits.
Rootkit: Rootkits have to be one of the worst forms of malware to be released in years. Rootkits disquise themselves as important computer processes and/or services or even as device drivers. Which make them undetectable to even the best Anti-Virus. Rootkits normally will render the computer very slow and often will disable many programs and applications such as the Anti-Virus to ensure it goes undetected.
Scareware: Scareware is a new term coined for a new breed of infection. Scareware will disable your computer and display a message upon the screen. The message is usually meant to scare the user into thinking they have done something wrong and will have to pay a fee/fine. The common canadian version often displays a false warrant from the RCMP (Royal Canadian Mounted Police) depicting that if the amount displayed is not payed in 72 hours action will be taken. However If the fee is payed then the money is lost and the infection will remain.
Spyware: Programs that monitor activity or information on your computer and sends that information to a remote computer without your knowledge.
Trojan: Programs that have been designed to appear innocent but have been intentionally designed to cause some malicious activity or to provide a backdoor to your system.
Virus: Programs that when run, infects other programs and files on your computer. These programs can have many effects ranging from wiping your hard drive or displaying a joke in a small box. This type of infection also tends to be localized to your computer and does not have the ability to spread to another computer.
Worm: Programs that when run, attempt to spread to other computers using either mass-mailing techiques to email addressess found on your computer or by using the Internet to infect a remote computer using known security holes.