The spam messages are being sent to Internet users worldwide, with an attached PDF file which urges them to buy shares in a company called Prime Time Group Inc. Investors may not be aware that the spammers have already purchased stock at a cheap price and are trying to artificially inflate its price by encouraging others to purchase more. The spammers plan to then sell off their stock at a profit, which may cause the price to plummet.
The massive spike in spam was first seen at Sophos's spamtraps in Germany at 16:40 BST yesterday, but was quickly seen arriving at other monitoring stations around the world. The e-mail messages are being sent from compromised home PCs, turned into compromised zombies by hackers.
"The scale of this stock pump-and-dump spam campaign is like nothing we've seen before, and it looks like it is working for the cyber criminals behind it. The share price in this company has rocketed as a result of bogus news being blasted to Internet users worldwide," said Graham Cluley, senior technology consultant for Sophos. "In an attempt to get past anti-spam products criminals are now regularly using PDF files to carry their slick enticements for potential investors. Although a solid anti-spam defense can protect against this menace, there are plenty of people who still haven't defended their e-mail gateways and are being fooled into making an unwise investment."
Experts report that pump-and-dump stock campaigns account for approximately 25 percent of all spam, up from 0.8 percent in January 2005.
