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“On a scale of one to 10, I would rate image spam as an 8” in terms of how troublesome it is, says Paul Judge, CTO of Secure
Computing. “This is because spammers have leapfrogged from hiding text within other text to now moving it to a place that
is unreachable by most antispam systems.”
Secure Computing is touting its TrustedSource Message Reputation fingerprints, which take a snapshot of a message identified
as spam and then assigns a correlating reputation score to it. The company is adding ImagePrinting technology to this service
that creates fingerprints specifically for images.
While spammers can circumvent fingerprinting by changing even one pixel in the image, Judge says Secure Computing’s ImagePrinting
technology performs image normalization “to ignore variations and focus on reoccurring parts.”
Tumbleweed on Tuesday introduced its Adaptive Image Filtering technology designed to block image spam by using an image-processing
technique called wavelet transform, which reduces an image to a mathematical formula that represents the message but still
allows for variation, according to company officials. With the addition of this new filtering technology to Tumbleweed’s e-mail
security appliances and software, the products can catch image spam that has been randomized in order to circumvent spam filters,
they say.
The company has already analyzed thousands of image spam messages and continues to build its pattern-matching database to
check incoming e-mail messages against, officials say.
Whether or not antispam products can catch this new variant of spam, this huge increase in unwanted e-mail levels is concerning
because it necessitates more bandwidth and computing power for anyone running an e-mail system, says Levine.
“Spam is huge tax on e-mail, and the tax just doubled,” he says.
