July marks 25 years since the first computer virus escaped into the wild. Spreading via floppy disk between systems in 1982, the Elk Cloner virus did nothing more incendiary than make a poem appear on users' screens. Hardly a heavy payload.

But given that the first virus predates the IBM PC, which machine was first infected? It was none other than the famous Apple II, surely prompting a cacophony of jokes about Apple 's claims to be virus-free.

The 1982 virus was thought to be the work of a 15-year-old student from Pittsburgh. Who'd have thought his creation would pave the way for today's blended threats and money-grabbing irritations.

Some believe the label of first virus should actually be accredited to the early 1970s Creeper infection on ARPANET. The program gained access through a modem and displayed the screen message 'I'M THE CREEPER : CATCH ME IF YOU CAN'. However, Elk Cloner could still be called the first virus for a consumer-level computer, we guess.

In 1982 researchers John Shoch and Jon Hupp of the Xerox Palo Alto Research Center (PARC) first used the term "worm" in a research paper. However, according to security vendor Symantec, the first instance of a computer virus being called such was in Fred Cohen's 1984 paper: 'Experiments with Computer Viruses'.