Types of Malware

Many terms are used to describe malware. Some are used to describe the delivery method. Others are used to describe what the malware does.
Delivery Method Terminology
Virus: A computer virus is a piece of malware that makes a copy of itself and attempt to spread itself to other computers over a network. Viruses can infect a computer with little or no action on the user’s part. (Read more: Wikipedia)
Trojan: A trojan is malware application, or an application infected with malware, that the user downloads and installs, not realizing it can cause harm. Like the “trojan horse” it is named after, the software appears to be something else. It does not attempt to spread itself further. (Read more: Wikipedia)
Functionality Terminology
The worst malware attempts to either harm your computer, deleting data, or it tries to steal come critical information like banking numbers or account passwords. Many malware terms apply to what the malware does once it is installed.
Spyware: This would record what you are doing, such as web sites you are visiting or email you receive and report it back to a source. A keylogger is spyware that records each keystroke, perhaps obtaining passwords in the process. Often spyware is installed by the owner of the computer to spy on a user, such as an employee, parent, spouse or school authority. (Read more: Wikipedia)
Adware: This could describe any software that includes advertisements, including completely legitimate software. But sometimes viruses or trojans can show advertisements or replace web advertisements without even implied permission from the user. (Read more: Wikipedia)
Back to the Mac Virus and Malware Information Center.