Received an e-card invitation in the last week or so? If not, you’ve been left out of one of the most notable spam-to-virus scams of the summer.

The scam itself is just another attempt to get people to visit rogue websites under the pretence that they’ve been sent, er, and e-card. Yes, that simple. They look convincing too, using the names of well-known e-card greeting purveyors to hide behind.

But there are several interesting elements to this trick. First, is its scale, anecdotally affecting a huge number of people at almost the same time in recent days. Almost every email address I use has received one, something not seen since the early days of the modern spam surge in 2002.

Second, the fact that the emails have succeeded in reaching so many people tells you that the gateways that normally stop such emails have not worked for some reason. So why haven’t they worked? It turns out that the spammers have turned to an astonishing innovation, one that will have anti-spam designers banging their forehead on the nearest table for weeks – they send the spam in, - yes- PLAIN TEXT rather with html formatting.

Plain text as a innovative form of attack? Not long ago, text would have been a barrier, but nowadays email clients have the ability to convert such links into hyperlinks, thus neatly doing the scammers’ work for them (ie sending html would have made the suspect links stand out to gateways). Gateways can spot trouble in such emails but only if triggered by keywords.

You feel sorry for anyone sending a genuine e-card. Anyone sending me one from now on is definitely off my Christmas card list.