Spam Junk Empire Uncovered

"The complexity is what's amazing to see," said Mr Peterson, chief technology officer of security firm Ironport who led the investigation.

Many of the junk messages had hidden classic work text in an attempt to convince spam filters that the messages were genuine and not junk. Analysis revealed that there were more than 2,000 variations in the content of the messages, more than 100,000 hijacked home computers in 119 nations had been used to despatch the junk mail; 1500 web domains that acted as the web shops for the drugs advertised in the junk messages.

"They were trying to make it look as legitimate as possible," he said.

Link