(WEB HOSTING INDUSTRY REVIEW) — German email security provider eleven (www.eleven.de) is warning all email users about a new trick seen in some spam campaigns that uses JavaScript to circumvent spam filters.
According to eleven’s Thursday announcement, these messages contain a HTML attachment which, when opened, activates a script that redirects the user’s browser to the spammers’ target site. The trick is used to circumvent spam filters, which search for links to known spam or phishing sites in the email content. This method makes spam detection more difficult because the email does not contain a link but rather directs the browser to the intended website via JavaScript.
Most often, eleven said, this is used by online pharmacy sites typically used in spam campaigns, however, one spam email detected by eleven redirected to a social networking site that has been used for phishing purposes in the past. The spam campaigns also use various subject lines and topics to lure recipients such as a password reset request for a popular social networking platform, fake domain registration conformations, or seemingly personal messages with subjects such as “You’re My Everything” and “You Are My Sunshine.”
In terms of combating this sort of attack, eleven’s eXpurgate technology detecting spam and categorizes emails based on key characteristic of all spam including its distribution scale, enabling eXpurgate to detect such spam messages with a high level of reliability.
eXpurgate’s “bulk check” technology involves proprietary checksum algorithms that reduce each email to a code made up of just a few bytes that gives no indication of the original content of the email. This code is checked against the codes of other emails, and when similar codes are found often enough, there is a high probability that the email is spam. Other inspection procedures help distinguish spam from more welcome mass mailing such as a popular Web hosting newsletter.
According to eleven’s latest email security report, the monthly volume of malware spread via email has increased more than fourfold since the beginning of the year, and Trojans accounted for 69 percent of all malware sent by email in April and May.
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