Slashdot Mirror
Spam Opt-out Link Triggers Malicious Code Attack
Maestro4k writes "The Register is reporting on a new spam E-mail circulating out there. In it, clicking on the 'Click here to remove' link launches a site, that when the user scrolls the page, triggers a drag-drop javascript exploit. Scarily the E-mail actually complies with the CAN-SPAM act as it only requires spammers to put an opt-out link in their mailings. As The Reg says "It comes as little surprise that this feature is been taken advantage of in a social engineering exploit; but it does illustrate the security problems of the opt-out approach that were always apparent to security experts - and ignored by legislators." The link in questions points to www. xcelent.biz (As in The Reg story, space intentionally included) so even if you can't block the mail yet it should be easy to block access to the site with the exploit. I suspect this is just the beginning and most spam will include "features" such as this in the near future."
Here is the pertinent CERT advisory for this flaw.
The idea is that all the website designer has to do is make an image that LOOKs like a scrollbar. The user goes and clicks and drags it to scroll down, not knowing it's fake. If there is a DYNSRC="..." attribute specified in the <IMG...> tag, Internet Explorer downloads and runs whatever program is specified, without any kinds of prompts whatsoever.
Even with SP2 installed.
Spammers have often used an "unsubscribe" link or something similar only to verify your email address and send you more spam. While not the same as triggering an exploit, I've been under the impression that spammers have taken advantage of users with an "opt out" type of link in this way for quite a while now.
The article didn't give much explanation about the drag-and-drop exploit itself. Understandably, given the audience, but I was curious. Here's a good link: http://xforce.iss.net/xforce/xfdb/13679
That comment means it was ripped from a proof-of-concept website published a while ago: http://www.mikx.de/scrollbar/ Amazingly shameless. They stole this guy's code, AND they're using it for phishing attacks.
http://www.xcelent.biz/d/ is a link to another page in that domain. Also has more graphics for better slashdotting potential.
P.S. Still be careful. They could always move the pages around.