Can Cookies and Graphic files pose a threat?

Cookies a threat?

We have seen a number of products that claim to protect you against viruses in cookies. So...cookies must pose a real threat, right? Nope!

Cookies are simply data files that some web sites will save on your hard disk. They are never executed so they pose no virus (or trojan) threat to your PC at all. Cookies pose no threat beyond wasting a small amount of disk space. Web sites store information about your visit to the site in these files. Both MS Internet Explorer and Netscape browsers give you some control over whether you will accept Cookies. You can configure your browser to accept all cookies, refuse all cookies, or the browser can ask you each time a web site wants to store a cookie on your disk. These files are normally stored a separate "cookie" directory (folder).

Are Graphics a Threat?

Just as with cookies, we have seen a vendor that claims to protect you against graphics. Almost all web site contain a large number of graphics that are downloaded and automatically displayed on your screen. You can also directly download graphic files (usually *.JPG or *.GIF files) and view or print them on your PC.

These graphic files do not contain programs. They are simply data that a viewer program interprets in order to display an image on your PC. If a virus were contained in one of these files, it would pose no threat since it would never be executed.

The Graphics Virus Myth

There are two reasons that the graphics virus myth won't die. One is that it happens all too often that someone clicks on a graphic and then has their PC crash (sometimes with damage to the programs and data on the disk. This is due to bugs (or conflicts) in the browser software not because of an attack from a virus or a trojan. See The "Cute Chicken" and related hoaxes. The other reason is that there have been a number of virus infected Usenet postings (often in the sex related areas) where the graphic files include a viewer program. Such a program (unlike the graphics themselves) can easily be infected.

Document Last Modified August 12, 1998
Ultimo aggiornamento della traduzione: #inserire data#