Lastly, and perhaps most significantly, is the issue of forebearance. The anti-virus vendors usually know more about the potential exploits inherent in programs than virus authors but they are bound by the fact that should they try to prevent them before the exploits occur, they could be branded as irresponsible for teaching virus authors about these very exploitsFor example, when Microsoft first released the macro capabilities of Word, anti-virus vendors immediately realized the potential for danger in macros, but they were handcuffed. If they released software that disabled macros before the first macro virus was ever released, they would signal to virus authors the inherent destructive powers of macros. They chose instead to wait, handcuffed by the limitations of desktop software.

Until the Internet there really has been no better medium for delivering virus solutions than desktop software. It was relatively inexpensive to deploy (either market the software and sell it in stores or provide free downloads on bulletin boards and web sites). It is, however, expensive to keep updated in terms of time and effort, even with automated update systems.The Internet caused several things to happen: by becoming a powerful medium for sharing files, whole families of viruses disappeared practically overnight (boot sector viruses, for example); by becoming the option of choice for sharing files, it was easier to infect a single file and have thousands download it.