A computer _______________ attaches itself to some sort of executable code like a program. When the program is running, it touches many files, each of which is now susceptible to being infected with the virus. So, the virus replicates itself on these files, does the malicious work it's intended to do, and repeats this over and over until it spreads as far as it can.

Google IT Support Professional Certificate Course 5
IT Security: Defense against the digital dark arts

This course will help you understand:
- how various encryption algorithms and techniques work as well as their benefits and limitations.
- various authentication systems and types.
- the difference between authentication and authorization.
- how to evaluate potential risks and recommend ways to reduce risk.
- best practices for securing a network.
- how to help others to grasp security concepts and protect themselves.