Christmas Storm

Note: This entry has been restored from old archives.

It’s been a while since I’ve had a Zhelatin/Storm/Nuwar mail get through to my inbox. Just in time for Christmas I get a shiny new one! It wishes me “Merry Christmas Dude” and provides a suitable URL for the season, no suspicious IP address link for this special occasion.

This one is a little different to previous efforts I’ve looked at. The embedded javascript isn’t malicious at all, in fact it is JSnow v0.2 complete with copyright notice. Snow! Joy! Is our favourite bot-net wishing us all a good Christmas out of good old fashioned social benevolence? Ha, fat chance! The page displays for us a set of scantily clad Mrs Clauses, enticing us to click on them for more. The link is to stripshow.exe, just less than 50% of the scanners on detect this at the moment. The list of ones that miss is conspicuously a round-up of the set with the largest market-share (interspersed with the ones that simply suck), this shouldn’t be any surprise these days.

It doesn’t stop there though, in a further effort the page embeds a javascript
in a I-Frame. And behold! We see the expected obfuscation code. So, in the end this isn’t really much different to previous sightings. I guess this strategy is still paying off for the crims behind it. It’s a sad indictment against the state of Internet security and security awareness that even after so many months this seemingly still works.

This time the javascript obfuscation is far more complex than others I’ve seen. Rather than a couple of simple translations we have several loops employing shifts and a variety of other bitwise operators (didn’t even know ECMA had an LSR operator). I guess they’ve invested some of their research time into this aspect of their code. At the moment only three of the scanners have anything to say about this and that’s just something along the lines of “generic obfuscated HTML”.

I wish people an infection-free Christmas. Have a good one.