Just before Christmas, a strange image arrived in my email in-box. It was attached to a message entitled “Extreme shrinkage was evident, due to the large amount of fat rendered” – a statement, I think you’ll agree, guaranteed to arouse anyone’s curiosity.

The image consisted of an assortment of geometric shapes on a burgundy background – the overall effect being not dissimilar to a “party shirt” I had in 1983. Over the top of this assemblage was a lengthy message urging me to invest in a “hot stock” listed on the market under the somewhat unfortunate acronym ARSS. Apparently I needed to start watching ARSS (insert joke here) as it was about to embark on a spectacular rise. $$$ were promised. And all this highly valuable information was set in a crude machine typeface with the kind of leading and kerning worthy of David Carson on one of his most, err, inspired days.

According to Ironport, a spam filtering firm, unsolicited junk mail now accounts for more than nine out of every ten email messages sent over the internet. The volume of junk has doubled over the last year, chiefly due to what was sitting in my in-box: image spam, one of the most successful and effective design innovations of recent times.

A report in the New York Times claims that “image spam increased fourfold from last year and now represents 25 to 45 percent of all junk e-mail”. Its growth is due to the fact that it is very hard to detect using regular filters. As the NYT explains, “Traditional anti-spam software examines the words in a text message and, using statistical techniques, determines if the words are more likely to make up a legitimate message or a piece of spam.”

Image spam gets around this by placing the message within an image. A typical email contains random text, often lifted from news sites so that it can sneak through the filters. Attached is a gif, which may be offering Viagra or fake watches but is most likely to be plugging a stock in what security experts pithily term a Pump and Dump scheme. By persuading a few gullible recipients to buy the shares advertised, the sender can take advantage of the ensuing short-term price rise, getting rid of their holding before prices head south once more. And it works. A recent study found that the price of spammed stocks rises on average by 5 per cent.

To combat image spam, the NYT says, filtering companies began to use optical character recognition, which scans the images in an email and tries to recognise any letters or words. Displaying an admirable talent for design innovation, the spammers hit back by covering their images with visual noise and abstract shapes (like my shirt), to throw the filterers’ scanners off. Apparently, animated spam is the next weapon waiting to be unleashed.

Being somewhat sad, I started collecting these bits of twenty-first century graphic ephemera as more and more landed in my in-box. Here’s a small selection.

Displaying his usual, uncanny predictive abilities, Bill Gates once forecast that “the junk mail problem will be solved by 2006”. Thanks to the ingenuity of their designers, the spammers have proved him spectacularly wrong. Another design success story.

PS Florian from Hi-ReS! has just been in touch to remind me of their brilliant Christmas card on the same theme (shown below). Click here to see the full animated version in all its glory.