Activities of Computer Viruses:
The majority of computer viruses are relatively harmless; their purpose is to annoy their victims rather than to cause any specific serious damages. Other viruses are indeed malicious. They can do great damages to a computer system if they get executed anyway.
Viruses can be programmed to do many kind of harms including the followings,
- Copy themselves to other programs or areas of disks
- Replicate as rapidly and frequently as possible, filling up the infected system’s disks and memory, rendering the system useless
- Slow down the computer system by occupying RAM spaces
- Losing control on various hardware as their drivers get infected
- Some viruses cause unwanted restart which occurs very frequently and are scheduled by the viruses
- Display information on the screen
- Modify, corrupt or destroy selected files
- Erase the contents of entire disks
- Lie dormant for a speified time or until a given condition is met and then become active
- Open a back-door to the infected system that allows someone else to access and even take control of the system through a network or internet connection
- Corrupt / Delete system files and force to re-install OS
- Spamming using internet connection and making the network useless.