If you opened the attachment you would see a list of passwords to pornographic websites. However, in the background, Melissa was checking if you had Microsoft Outlook, an e-mail programme. If you had, it sent itself to the first fifty people in your address book. If they opened the attachment, Melissa would spiral onwards. This has become increasingly common.
Standardisation has definite advantages.
If everyone in a large company is using different systems and software, then support becomes complex and costly. The organisation of information so that it can become widely accessible also becomes extremely difficult. Even basic communication can be difficult. The internet has solved many of the above problems, creating a very open system for communication and organisation of information. However, when you combine the internet with a Microsoft monoculture, you get an environment that is open to attack, as Melissa proved so simply and dramatically.