"Generating images like this is, of course, more computing intensive but spammers have lots of computing power at their disposal via the huge botnets they are running. It’s not like they couldn’t afford to render unique 3D spam for every recipient," F-Secure wrote on its blog.
The new method aims to get such spam emails through spam filters and seems to be at least a little bit effective nowadays. However, updates are bound to come and render it useless, as the war between security researchers and spammers knows no truce nor end.