Daniel I agree a nat/firewall/router with acl's ... will all help prevent windows compromises. I believe security in depth is an essential element of any good security system. The goal of this document is help new XP users survive long enough to do their updates. Many of them cant/wont put up acls/nat/firewalls ... but if they follow the steps listed they have a better chance of successfully downloading and updating their new machine then they will have with OUT these steps. It is not meant as a complete XP hardening document. There are lots of documents that discuss in detail how to harden windows (xp,nt,2k...). Donald.Smith@qwest.com GCIA http://pgp.mit.edu:11371/pks/lookup?op=get&search=0xAF00EDCC pgpFingerPrint:9CE4 227B B9B3 601F B500 D076 43F1 0767 AF00 EDCC kill -13 111.2

-----Original Message----- From: owner-nanog@merit.edu [mailto:owner-nanog@merit.edu] On Behalf Of Daniel Senie Sent: Tuesday, May 04, 2004 9:39 AM To: Sean Donelan Cc: nanog@merit.edu Subject: RE: FW: Worms versus Bots

At 10:54 AM 5/4/2004, Sean Donelan wrote:

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On Tue, 4 May 2004, Smith, Donald wrote:

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If you follow these steps outlined by SANS you should be able to successfully update and NOT get infected. This is short, easy, fully documented (with pictures :) http://www.sans.org/rr/papers/index.php?id=1298

The risk is smaller, but still exists if you follow these directions for XP pre-SP2. See the Microsoft release notes for XP SP2 for details about the fix.

If you do not have XP SP2, you need to disconnect your computer from the network prior to every boot cycle until it is fully patched.

A much simpler mechanism than that described by SANS is to have a small, cheap NAT box in your bag (e.g. D-Link DI-604 or similar). Worth the $50 cost to have one available. Put the little router between the new machine to be brought up and whatever network you have access to. Now you can bring up the new machine and update it without having it get instantly infected. (Use some common sense... don't set up email until the machine is patched, or use any other sort of mechanism to pull in potential viruses before patching is done).

(To deflect the inevitable "NAT is not a firewall" complaints, the box is a stateful inspection firewall -- as all NAT boxes actually are).