CCIE Security Exam Quick Reference Sheets

Chapter 8. Security Solutions

Viruses, Trojans, Worms, and Spyware

Viruses

• A virus is a malicious computer program written with the goal of harming the host it attaches to and executes on.
• Viruses, once they are resident in memory, often delete and modify important files on the infected computer.
• Successful viruses require the program to be executed by a human by opening a program or during computer restart.
• Viruses when run might infect other programs on your hard disk by copying themselves onto the programs.
• Viruses can delete files, erase programs, or destroy all data on a disk.
• Viruses usually attack the host's executable program files, its file-directory system that tracks the location of all your computer's files, its boot and system areas ...