You see these terms all the time when we talk about phone and computer malware, but what exactly is the difference between a Virus, Trojan, and Worm?

While they can all steal your information and damage your device, there are some differences.

Virus – Technically, a virus infects another file (attaches or inserts itself into it). They usually infect program files or MS Office documents. From there, it can replicate, do damage, etc. Unlike a worm, these do not function as a stand alone (except possibly to infect a given file).

Worm – This is almost identical to a “true virus”, except that it lives on its own and generally doesn’t infect other files (although it can replace them).

They get onto your device through a vulnerability in the network. Usually, these replicate themselves. Again, these are very close to a true virus, and can do the same kind of damage.

Trojan – This type of program doesn’t copy itself but does do damage to your computer, tablet, or phone. These types of programs rely on people to pass them around and to run them. They do not transmit themselves. The idea is to make the program look like it’s something harmless like a video or an app to trick you into running it.