Recently, Google pulled around 60 apps from the Android Market because of malware concerns. According to the company, the apps, which were downloaded by around 200,000 users combined, were being used to collect sensitive information about users, while installing malicious code on affected devices. Google suspended developer accounts and contacted the authorities.

The situation conjuresup the not-so-pleasant reminder of just how far malware has come in the past four decades. It's evolved from the stuff of science fiction to an ever evolving threat across a spectrum of devices that we rely on every day.

This past January marked another dubious milestone, as Brain, the first reported self-replicating MS-DOS virus celebrated its 25th birthday. Looking back, Brain seems almost quaint: It was a virus that required the manual exchange of floppy disks between users, in order to propagate.

Since then, of course, the world has become infinitely more connected, and as with their analog namesakes, computer viruses thrive on connectedness. In recent years, mobile devices and social networks, such as Facebook and Twitter, which thrive on sharing, have become hotbeds for infection. And while protection against such threats has evolved at a rapid pace, the threats themselves also seem one step ahead, intent on infecting as many systems as possible, destroying precious information in the process.

To mark this less than joyous occasion, let's take a look back at malware of systems past, from the poem reciting virus of the 70s to the worms of today, which wreak global havoc on our worldwide networks. It's hardly a definitive list, but it should give you some insight into just how far (unfortunately) malware has come.