Info about Computer Viruses
What is Virus?
A program designed to infect computer systems.
Viruses are generally malicious programs created to cause damage or annoyance to computer users. The effects of viruses range from harmless but annoying messages announcing the presence of an "infection" to malicious corruption or deletion of crucial operating system and data files.
Although the term virus is generally used to refer to any form of malicious code, technically viruses that infect computer systems do so by attaching themselves to executable files, and when these files are executed the virus spreads to other files or causes various forms of damage such as lost or corrupted data. Some other related forms of "malware" (malicious software) include
• Worm:
It is a code that infects a machine and then spreads itself to other machines on the network. Worms do not need a host application to attach themselves to as viruses do. Some worms also multiply on host machines and cause various forms of damage to operating system or user files similar to that which viruses cause.
• Logic bomb:
It is a code that executes when certain conditions occur-for example, on a specific date of the month or year. Logic bombs are really a form of virus or worm, depending on what actions they perform when the trigger.
• Trojan:
It is a code that masquerades as a legitimate application, usually to trick users into divulging their credentials or other sensitive information.
• Hoaxes:
These are not viruses at all but simply threats of viruses. This might seem innocuous, but many industry analysts say that enterprise administrators often spend more time dealing with these hoaxes than in eradicating actual viruses, and in a business environment any time wasted is money wasted.
Viruses have many entry points in today's enterprise networks, including Internet connections, remote access connections, electronic mail, and users downloading and saving software from the Internet onto floppy disks and taking these disks to work to install the software on their office machines.