Pundits have long predicted that the growing number of viruses and worms and their ability to spread around the world within hours would render scanners slow and impractical. Back in the days of the 640KB DOS barrier, industry observers said virus scanners would eventually run out of memory. Even antivirus-scanning supporters have awaited the day when encrypting polymorphic viruses would become so good at hiding that false positives and false negatives would become overwhelming and kill the scanner.
However, despite all the predictions of their eventual demise, antivirus scanners have survived. Like their enemies, virus scanners have morphed with the times. Today, scanners are extremely efficient at inspecting code and have been able to defeat all the defense mechanisms that malware writers have attempted. The scanner might one day become passé, but a more likely scenario is that the product we use in the future to protect our computing resources will have evolved from today's virus scanner.