Botnets, IRC servers and firewalls?

[Paul Robertson <proberts () patriot net>]

Seems like we're seeing more and more botnet infections going out to IRC
servers.  Granted several of these infections go to servers on different
ports than the default, but a significant number of them are hitting
servers on tcp/6667.

Now that most firewalls don't proxy, it seems way too many places are
allowing TCP straight out to any port, so long as it originates inside
(certainly the "NAT is a firewall crowd.")  How many people routinely
block TCP/6667, or non-allowed applications?  How many of you who don't
block it do regular reports on connections initiated inside to external
servers that aren't on port 80, 443, etc?

I was tempted to save all the mydoom samples I got and map them back
to netblocks to see how many were home users, and how many folks allowed
SMTP straight out.  But I didn't have the patience to sort through all the
messages.

Firewalls are certainly capable of blocking a lot of this stuff- and I
don't believe that the problem is just home users- am I wrong, or do we
have too many places with too lax a security policy anymore?

($diety knows we've got too many content filters and AV bouncers- I'm
about to start collecting regexps for those to add to my block lists.)

Paul
-----------------------------------------------------------------------------
Paul D. Robertson      "My statements in this message are personal opinions
proberts () patriot net      which may have no basis whatsoever in fact."
probertson () trusecure com Director of Risk Assessment TruSecure Corporation
_______________________________________________
firewall-wizards mailing list
firewall-wizards () honor icsalabs com
http://honor.icsalabs.com/mailman/listinfo/firewall-wizards