- Computers & Software
SEVERALS TYPES OF COMPUTER VIRUSES
TYPES OF COMPUTER VIRUSES:
There are now several hundreds known viruses with more appearing with the passage of time Two categories of viruses are:
i) Time Bombs: that are triggered by a particular date like April 26
ii)Logic Bombs: That are triggered by a set of conditions such as the number of files on a disk reaches a specific number or when certain combination of letter is typed.
Some of common viruses are:
italians (also called Ping Pong or Bouncing Ball). Once every half hour a bouncing dot is triggered bouncing off the edge of the screen and passing through any text on the screen, replacing letters with random characters.
ii)Stoned corrupts the FILE Allocation Table (FAT), thus causing file directory entriees to be deleted on floppy disks so that user files are effectively lost.
Data Crime is a particularly vicious virus which operates between two fixed dates like October 13 and December 25 reformatting the hard disk with consequent loss of all data programs stored on it.