Interesting spyware push download tactic...

Incidents.org has another interesting post about a spyware site. One of the handlers ran across it while doing a search for an educational institution. (They've used a wildcard in the dns record so that they can get traffic to {fillinkeyword}.nastydomain.com) Anyway... the main page tries to install WinAntiSpyware2006FreeInstall.cab from WinSoftware Corporation, Inc. It gives the little ActiveX control popdown bar and insists that it must be installed to view the page properly. But that's not the most interesting part...

It looks like they're filtering access to the page based on the User Agent of the browser, if it's IE you get the push install, if it's not... Page not found. They discovered this because they put on the "rubber gloves" of web security research and tried pulling up the page with wget to see what it looked like. 403 denied... Then they tried out Firefox and got a 404 not found. Finally, they tried wget with the -U option to specify a User Agent... like this...

wget -U "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)"

And with that (and the address), they were able to grab the index.html

I guess that's a technique to try and slow the research of a push spyware download? According to Incidents, WinAntiSpyware2006FreeInstall.cab is detected as a trojan by some antivirus products. I wonder also if this could pave the way for spyware pushers to target specific browsers/platforms with different push downloads?