Last year's "image spam" scourge has slowed to a trickle as stock spammers turn to more sophisticated technologies to drive their "pump and dump" stock schemes. 

According to Nick Kelly, writing on the McAfee Avert Labs blog, image spam saw massive increases during 2006 and, during the first quarter of 2007, was responsible for about 60% of all spam.
"In the last few weeks, however, there has been a significant reduction in spam that contains embedded images, dropping from 59% at the start of April to 12% earlier this week," he writes.
"For the last year and a half image spam has typically contained embedded .GIF, .JPG, or .PNG images.
"Spammers, particularly German 'pump and dump' stock spammers, are now uploading the spam images to free image-hosting and photography sites such as imageshack.us and imagehosting.com and are linking to those images in their spam rather than including the pictures in the email.
"Another recent trend is spammers posting spam images onto compromised Web servers and then linking to the image in their spam," says Kelly.
"The amount of hosted image spam does not currently make up for the reduction in embedded image spam, but it is increasing in the same way that previous image spam has, as more spammers jump on this bandwagon."
In face, embedded image spam has increased to 31% of spam, so whether the pump-and-dump spammers were having a holiday during April and are now back at work, or if this is a temporary increase, remains to be seen, Kelly concludes.