Virus Types
A virus is an application that has two functions: multiply and activate at a signal date or signal count. It can harm you by deleting portions of your hard drive. However, a virus does not always do damage.
Executable
Executable viruses reside in executable files. They are literally extensions of executables and are unable to exist by themselves. The Melissa virus of 1999 was an example.
Trojan
Trojans are true, freestanding programs that do something other than what the person who runs the program thinks they will do. An example of a Trojan would be WinXP pro antivirus that claims to help you clean up some virus on your computer, which in fact infests your computer and render it useless. Some Trojans are quite refined. It might be a program that works perfectly, but when the user quits the program, it causes some type of damage.
Boot Sector
Boot sector viruses change the code in the master boot record (MBR) of the hard drive.
Macro
Macro viruses are specially written application macros. These viruses will auto-start when the particular application is run and will then attempt to make more copies of them-selves.
Worm
A worm is a very special form of virus. Unlike all of the other viruses described, a worm does not infect other files on the computer. Instead a worm copies itself on other systems on a network by taking advantage of security weaknesses in networking protocols. These were more common in business environments.
Bimodal/Bipartite
A bimodal or bipartite virus uses both boot-sector and executable functions.
Polymorphics/Polymorphs
A polymorphs virus attempts to change its signature to prevent detection by antivirus programs, usually by continually scrambling a bit of useless code.
Virus Prevention Tips
The secret to preventing damage from a virus attack is to keep from getting one in the first place. All good antivirus programs include shield protection that will automatically scan external media downloads, and so on. Use it. It is also a good idea to scan a PC daily for possible virus attacks. Again, all antivirus programs include TSRs that will run every time the PC is booted. Last but not least, know where software has come from before you load it. Although the chance of commercial, shrink-wrapped software having a virus is virtually non-existent (a couple of well-publicized exceptions have occurred), that illegal copy of “Microsoft Office” you borrowed from a local hacker should definitely be inspected with care. Get into the habit of having an antivirus flash drive, with a copy of a free antivirus program i.e. Microsoft Security Essentials or AVG. If you suspect a virus, use the flash drive, even if your antivirus program claims to have eliminated it. Turn off the PC and reboot into Safe Mode from the antivirus. Run your antivirus program’s most comprehensive virus scan. Then check all removable media that were exposed to the system and any other machine that may have received data from, or is networked to, the cleaned machine. A virus can often go for months before anyone knows of its presence.
General System Sluggishness
Every PC gets slower and stodgier overtime. You load and unload programs, you download stuff off the Internet, the system crashes and scatters temp files all over the place - all of these factors contribute to the decline of snappiness. Sometimes the decline comes in a more dramatic fashion, though. This is where a good defrag comes into place.
A virus is an application that has two functions: multiply and activate at a signal date or signal count. It can harm you by deleting portions of your hard drive. However, a virus does not always do damage.
Executable
Executable viruses reside in executable files. They are literally extensions of executables and are unable to exist by themselves. The Melissa virus of 1999 was an example.
Trojan
Trojans are true, freestanding programs that do something other than what the person who runs the program thinks they will do. An example of a Trojan would be WinXP pro antivirus that claims to help you clean up some virus on your computer, which in fact infests your computer and render it useless. Some Trojans are quite refined. It might be a program that works perfectly, but when the user quits the program, it causes some type of damage.
Boot Sector
Boot sector viruses change the code in the master boot record (MBR) of the hard drive.
Macro
Macro viruses are specially written application macros. These viruses will auto-start when the particular application is run and will then attempt to make more copies of them-selves.
Worm
A worm is a very special form of virus. Unlike all of the other viruses described, a worm does not infect other files on the computer. Instead a worm copies itself on other systems on a network by taking advantage of security weaknesses in networking protocols. These were more common in business environments.
Bimodal/Bipartite
A bimodal or bipartite virus uses both boot-sector and executable functions.
Polymorphics/Polymorphs
A polymorphs virus attempts to change its signature to prevent detection by antivirus programs, usually by continually scrambling a bit of useless code.
Virus Prevention Tips
The secret to preventing damage from a virus attack is to keep from getting one in the first place. All good antivirus programs include shield protection that will automatically scan external media downloads, and so on. Use it. It is also a good idea to scan a PC daily for possible virus attacks. Again, all antivirus programs include TSRs that will run every time the PC is booted. Last but not least, know where software has come from before you load it. Although the chance of commercial, shrink-wrapped software having a virus is virtually non-existent (a couple of well-publicized exceptions have occurred), that illegal copy of “Microsoft Office” you borrowed from a local hacker should definitely be inspected with care. Get into the habit of having an antivirus flash drive, with a copy of a free antivirus program i.e. Microsoft Security Essentials or AVG. If you suspect a virus, use the flash drive, even if your antivirus program claims to have eliminated it. Turn off the PC and reboot into Safe Mode from the antivirus. Run your antivirus program’s most comprehensive virus scan. Then check all removable media that were exposed to the system and any other machine that may have received data from, or is networked to, the cleaned machine. A virus can often go for months before anyone knows of its presence.
General System Sluggishness
Every PC gets slower and stodgier overtime. You load and unload programs, you download stuff off the Internet, the system crashes and scatters temp files all over the place - all of these factors contribute to the decline of snappiness. Sometimes the decline comes in a more dramatic fashion, though. This is where a good defrag comes into place.
