On Mar 21, 2011, at 1:43 PM, Cal Leeming wrote: > > > On Mon, Mar 21, 2011 at 8:39 PM, bk <[email protected]> wrote: > > On Mar 21, 2011, at 10:52 AM, Alien Chatter wrote: > > > $ sudo iptables -I INPUT -m string --algo bm --hex-string > > '|476f6f676c6520496e63311830160603550403140f6d61696c2e676f6f676c652e636f6d30819f30|' > > -j DROP > > > > Try it, you will get a connection timeout: > > > > $ curl --connect-timeout 60 https://mail.google.com/ > > curl: (28) SSL connection timeout > > > > The same applies for Twitter, Facebook... Much more efficient than > > DNS/IP blocking! > > > > Because searching for a bytestring in payload generates so much less load > than just overriding a DNS result at the recursive server (that users are > forced to issue queries to) or a simply drop SYNs based on IP header value > that routers/firewalls are optimized for... > > I think you forgot your coffee this morning. It's not just for aliens you > know. > > -- > chort > > _______________________________________________ > Full-Disclosure - We believe in it. > Charter: http://lists.grok.org.uk/full-disclosure-charter.html > Hosted and sponsored by Secunia - http://secunia.com/ > > I think what he meant by efficient, was that if their sites ever get > re-numbered or more end nodes are added (which may or may not be that often), > then this would still catch the connections. > > Imho, I think it'd be better to just have a script checking for it, but > nether the less, it's a cute approach (albeit, probably not usable in a > production environment).
It's "efficient" in that humans get to be lazy. It's not efficient as far as hardware resource utilization. -- chort
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