Spammers and hackers are taking a new tack in their evolving e-mail assault.

Dmitri Alperovitch, principal research scientist at Secure Computing, said that instead of embedding image spam inside of e-mail messages, cybercriminals are starting to embed only a link to a photo or image they've put up on a photo-sharing site. Alperovitch said in an interview that this makes it a lot easier and more cost effective for the spammers, who no longer have to embed a bandwidth-sucking image in every message spammed out.

"It still looks like the spam messages that have been sent out, but they'll be coming in much larger volumes," said Alperovitch.

Image spam, which hit the Internet just about a year ago, traditionally uses a graphic embedded in an e-mail rather than regular text because it makes it harder for antivirus software to detect words that generally send up red flags that the message is a piece of spam. Image spam is frequently used for promoting pump-and-dump stock scams or drugs such as Viagra.

Alperovitch said this new wave of image spam uses the logos of popular brokerage firms or images of pharmaceutical pills.

Photo-sharing sites are set up to allow people to upload their photographs so friends and family members can view them online.