Life and Death Virus

Viruses are not only virulent and destructive, they can also be sneaky, and many have methods that they use to avoid detection by anti-virus software. For example, some are able to infect files without increasing their size or damaging them. These viruses are called cavity viruses and achieve their goal by overwriting the unused areas of executable files. Other viruses kill the tasks that the anti-virus is supposed to carry out in its detection activities. As technology is constantly updated and computers and operating systems increase in complexity, the need for viruses to improve their deception techniques also grows.

Viruses are designed to avoid suspicious programmes, particularly small programme files or programmes that contain patterns of "garbage instructions". Another avoidance strategy that makes baiting difficult is sparse infection. This involves not infecting a file that would be an ideal host in other circumstances.

When it comes to preventing viruses, there are two common methods of detection that are used. The first is to use a list of virus signature definitions. The computer's memory is examined, along with any files on fixed and removable drives, and these are compared with a database of known virus signatures. The downside to this is that you are only protected to the date of your last update. If anything new has been released and you haven't updated your system you will be vulnerable to it. The second method is to use an heuristic algorithm that identifies viruses based on common behaviours. This enables you to identify viruses that security firms still have to create signatures for. It is important that you update your anti-virus software on a regular basis so that you can prevent the latest and most virulent threats from attacking your computer and destroying all of your data.