Risk
2/28/2007
10:00 AM
50%
50%

Like a Sieve

Ways to circumvent content filters, and why you should still retain them

8:00 AM -- In today's highly litigious corporate atmosphere, porn in the office isn't an option, if it ever was. However, more and more services are popping up to evade content filters, while at the same time the laws are becoming more and more strict against the whole concept of it.

So let's say I'm Mr. Joe Salesman and I have a thing for high quality porn. My home connection is a phone line, so it is far more convenient for me to download my high-resolution porn from the office since the office T1 line trumps my 56k modem. What can I do to get around those pesky content filters that blacklist Websites? Well, thankfully there are a plethora of sites out there to help with this.

Eventually, someone will get wise and block all of my proxies, so perhaps there is another way, including using Google itself, to serve up my porn. My office certainly won't block access to Google, and they wouldn't question a bit of traffic going to and from Google's Websites, so I'm pretty home free. Google is my new source for porn, while I'm surfing at work.

Now let's say someone finds out about my porn habits and attempts to get me fired. Then it's time to steal all the corporate secrets I am privy to as I get prepared to be fired. The stupid content filter will stop me from doing this, so I have to think of some way to encrypt the data in transit so the content filter won't pick up things like "Confidential."

My obvious choice is an SSH tunnel but what about using another language? Most content filters only speak one language. OK, that's good, but I don't speak another language and can't use a translation service since that would require uploading the content to them in the first place, defeating the purpose. My other option is to use pig latin, or simply add a few extraneous numbers in each word, or a dozen other incredibly simple tactics to obfuscate the text.

The point is, content filters are unable to keep up with the escalating interest in defeating them. So given that, are they worth having? The short answer: probably yes. If you can say that you are in a defensible position having done your best to stop it, it can save you a lot of trouble when you get on the witness stand. Also, it can help you detect users who aren't savvy enough to evade the content filters. So while I don't recommend them as an actual security measure, they can mitigate a lot of corporate risk.

— RSnake is a red-blooded lumberjack whose rants can also be found at Ha.ckers and F*the.net. Special to Dark Reading

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