Malicious software has been a problem since the early 1980, when viruses were normally transferred by floppy disks.
Email was then quickly adopted by malware, as well as, to a lesser extent, other transmission methods. Malware threats thus could spread far more quickly.
Malware is a continuing problem. New threats have evolved, such as phishing. where someone is tricked into disclosing sensitive information. And new methods of transmission are constantly being developed. An ongoing cat-and-mouse game is played between the malware developers, and malware control vendors.
Malware control has been a major focus of IT professionals since about 1995. As of 2012, malware appears likely to continue to be a problem for the foreseeable future.–David Ferris