I'm collecting a lot of phishing samples every day and most of them are part of big waves of spam... Millions of messages are sent with hope that at least some victims will fall in the trap. And sometimes, you find a nice (different) one like yesterday. It was a classic email with the subject "Important Notice" enticing the victim to open the attached file. The malicious file was an HTML document with an obfuscated JavaScript:

document.write(unescape('%3c%21%64%6f%63%74%79%70%65%20%68%74%6d%6c%3e%0d%0a%3c%68%74%6d%6c%3e%0d%0a%
3c%68%65%61%64%3e%0d%0a%3c%6d%65%74%61%20%63%68%61%72%73%65%74%3d%22%75%74%66%2d%38%22%3e%0d%0a%3c%74
%69%74%6c%65%3e%45%78%63%65%6c%20%4f%6e%6c%69%6e%65%3c%2f%74%69%74%6c%65%3e%0d%0a%3c%6d%65%74%61%20%6
e%61%6d%65%3d%22%67%65%6e%65%72%61%74%6f%72%22%20%63%6f%6e%74%65%6e%74%3d%22%57%59%53%49%57%59%47%20%
... (very long payload) ...
4%3d%22%22%3e%3c%2f%64%69%76%3e%0d%0a%3c%2f%62%6f%64%79%3e%0d%0a%3c%2f%68%74%6d%6c%3e'));

This is not complicated to de-obfuscate this payload (the code is available here). The attacker generated a page with an online HTML editor and added a form to capture credentials. The rendered page looks like a fake Microsoft Excel screenshot popping up a dialog box:

The HTML objects are downloaded from hxxp://tourkrabithailand.com/images/services/gr/ and credentials are posted to hxxp://mat-update.be/money/result.php. I contacted the Belgian CERT yesterday to report this website and the domain is already blocked.

Nothing fancy, bad design (why a blue "Download" button?) but it works! The JavaScript code runs below the radar with a low VT detection rate: 2/56 (link).

Xavier Mertens
ISC Handler - Freelance Security Consultant
PGP Key