In this article we will examine how the growth of Windows and Visual Basic affected the evolution of computer viruses, since along with the development of those two technologies we had the appearance of global virus epidemics, like the virus Melissa in 1999.
While Windows were evolving as an application designed to facilitate the management of the DOS in a 32-bit operating system, the virus developers returned to using assembly as the main programming language to create viruses. Versions 5 and 6 of Visual Basic (VB) were, together with the Borland Delphi (Pascal language environments for Windows), the preferred development tool for creators of worms and Trojan horses. Then Visual C came into play, which offered a powerful application programming language for Windows. Quickly C was adopted by the creators of viruses, Trojan horses and worms. Viruses based on the Visual C language acquired unprecedented power, supplanting all other types of viruses. Although the characteristics of worms have changed with time, all have the same goal: to spread to as many computers in the shortest possible time.
Over time, Visual Basic became extremely popular and Microsoft implemented it as part of the functionality of a separate tool: an “interpreter” capable of executing script files that contained code with similar syntax.
Simultaneously, with the establishment of the 32-bit Windows platform, the first script file viruses were born: These were hostile software hidden inside a plain text file. Script file viruses showed that the executable files (files with extensions. EXE and. COM) were not the only ones that could carry viruses. As we have already seen with BAT files for viruses, there are other means of spreading a virus, fully justifying the assumption that everything that can be executed either directly or through an interpreter, may contain a hostile software. Specifically, the first viruses that could infect the macros contained in the applications of Microsoft Office came into the scene. As a result, Word, Excel, Access and PowerPoint have become vehicles for the spread of lethal weapons, which destroy data even when users simply open a document.