Multi-defense-resistant spam.Over the past few months, Network Box Security Response has been closely monitoring, and responding to, the emergence of a new type of spam E-mail that is not requested. Also known as "unsolicited commercial e-mail" (UCE), "unsolicited bulk e-mail" (UBE), "gray mail" and just plain "junk mail," the term is both a noun (the e-mail message) and a verb (to send it). email They have named this "MDR MDR, n See multidrug resistance. MDR, n the abbreviation for minimum daily requirement, specifically the Minimum Daily Requirements for Specific Nutrients compiled by the United States Food and Drug Administration. Spam" (multi-defense-resistant spam). While, at first glance, all samples of such messages look identical, an in-depth technical analysis of 1,204 samples of this spam, arriving at a single Network Box, showed they came from 600 unique senders (in 41 different countries), with 599 digitally different copies of the GIF GIF in full Graphics Interchange Format Standard computer file format for graphic images. GIF files use data compression to reduce the file size. The original version of the format was developed by CompuServe in 1987. image (all of which "appeared" to be the same). Without a sender, source ip, message structure, or unique digital fingerprint fingerprint, an impression of the underside of the end of a finger or thumb, used for identification because the arrangement of ridges in any fingerprint is thought to be unique and permanent with each person (no two persons having the same prints have ever been to lock-on to, it is very difficult to detect and block such spam (without an unacceptably high false-positive rate). Statistics show that the rate of such MDR spams has been rapidly increasing over the past few weeks (from less than 0.1% a year ago, to up to 18% this week). Overall, image spam An e-mail advertisement in the form of an image in the message rather than text in order to avoid detection as spam. Spam filters typically analyze words in a message, which is relatively fast, but scanning images with optical character recognition (OCR) to extract the text is slow. has increased from 1% a year ago, to up to 25% this week. Up until now, we have been responding to such outbreaks with message structure analysis and blocks tuned to match each outbreak. We have also used digital signatures of message components. While effective, such techniques typically take hours/days to be successful in blocking such outbreaks. By that time, often a new outbreak is released. www.network-box.com |
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