This last week we saw the twentieth anniversary of one of the most infamous computer viruses the world has ever seen - and it relied on these two aspects of human behaviour to be so devastating.

Looking back now the 'Love Bug' seemed so incredibly simple and basic. Filipino Onel de Guzman, aged twenty-four at the time, sent out an e-mail with an attachment. The subject line of the e-mail was "ILOVEYOU" and it had an attachment which was called "LOVE-LETTER-FOR-YOU.TXT.vbs"

What brilliant social engineering!

Someone is in love with me? What have they put in the letter? In some circumstances you knew the person who sent it to you or it may have been a name you didn't immediately recognise.

Most people couldn't wait to open the attachment to find out more details about the person who was smitten with them - but to their disappointment nothing was there.

Nothing they noticed anyway - except their computer was now infected with a virus and, more importantly, everyone in their address book was sent a copy of the virus. You were now professing your love for someone else, and on it went. To approximately forty-five million computers around the world. Guzman has said that, as a young student, all he was after was free Internet access but not in his wildest dreams did he imagine that he would shut down the UK Parliament and impact the Pentagon.

The first documented virus was the Creeper program which was released way back in 1971. It was not malicious and was really just a test of a self-replicating program.

As computers developed, some programmers liked to experiment with ideas. In 1981, Elk Cloner used floppy disks that the Apple operating system was stored on to infect Apple II computers and in 1986 the first IBM PC compatible virus was launched. Over the ensuing years various viruses were launched with some level of notoriety - such as Michelangelo;Ping Pong; Father Christmas; CIH and more. In relative terms, these were not widespread.

What a virus needed was a better transmission tool. And that tool was the Internet.

Since the Love Bug we have seen many major outbreaks such as Code Red and MyDoom and only three years ago the WannaCry ransomware attack. The world is certainly more awareof the potential damage that can be done and antivirus software is more sophisticated - but the programmers are also more advanced in their attacks.

And what happened to Guzman, the writer of arguably the most infections virus the world has seen? It was a case of legislation being out of date. There was no law against malware in the Philippines at the time so he was never prosecuted.

Tell me if you feel safe against computer viruses at ask@techtalk.digital.