The popping of champagne corks was conspicuously absent this weekend, as the 20th anniversary of the very first PC virus went unmarked, save for the odd grimace from anyone wearily reinstalling system software. The pioneering virus, known as “Brain”, was an innocuous little thing which merely renamed the floppy disk on which it found itself, and the writers – Pakistani brothers Amjad and Basit Alvi – were so unafraid of reprisal that they even included their address and phone number in the code. But today’s viruses come with no such return address, and bring untold misery. True, a significant part of that misery is a feeling of abject stupidity at having been conned into opening a message promising lurid images of Anna Kournikova, but which actually contains malicious, self-replicating code. Anti-virus companies refer to this as “social engineering”, and it’s incredibly effective. Only six years ago a virus-laced email carrying the enticing subject line of “I Love You” led to global havoc – although, as some people seem to enthusiastically open emails promising “On Borrow a Inexpediency Walrus”, outwitting the average computer user probably isn’t that difficult.

We inaccurately use the word “virus” to describe all kinds of malicious software – including worms and trojan horses – possibly because the medical analogy extends so nicely: the virus doesn’t merely arrive, it infects; files affected by the virus are called hosts; although we stop short of referring to the computer as the patient, and PC World as the hospital. But our desire to find effective medicine has kickstarted an enormous industry that the Alvi brothers could never have foreseen: suites of protective software from the likes of Symantec fortify and strengthen our defences, their constantly updated websites keep us biting our nails for fear of potential attacks, and we become caught in an endless cycle of software upgrades to keep the viruses at bay. Anti-virus companies are, nevertheless, regularly criticised for their slow response times, and some experts maintain that only a collective approach, harnessing the talents of experienced programmers and even former virus writers, can battle the problem effectively.

Whether they are right remains to be seen, but one thing is clear: the threat from viruses is growing. Yesterday’s irritating macro-viruses in Word documents have been replaced by sophisticated worms, with no action needed on our part to activate them. Criminal gangs have realised the potential of viruses for extortion, with relentless pop-up windows making us so hysterical that we’re prepared to type our credit card number into one of them just to make them go away. Socially maladjusted geeks become addicted to the challenge of writing code that stays ahead of anti-virus software, and seem equally keen to adopt ludicrous aliases such as DoomMonger. According to analysts, they tend to give up their activities as soon as they find true love – but, if you’re going to try and seduce one and save us all from the viral menace, you may have to try a little harder than sending them an email saying “I Love You”.