nanog mailing list archives

Re: RBL for bots?


From: Gadi Evron <ge () linuxbox org>
Date: Thu, 15 Feb 2007 19:02:12 -0600 (CST)


On Thu, 15 Feb 2007 Valdis.Kletnieks () vt edu wrote:
On Thu, 15 Feb 2007 11:30:34 EST, Drew Weaver said:

    Has anyone created an RBL, much like (possibly) the BOGON list which
includes the IP addresses of hosts which seem to be "infected" and are
attempting to brute-force SSH/HTTP, etc?

No BL for bots other than SMTP zombies quite yet.

There is one for SSH brute forcing, although home-made.. J. Will repond on
his own...

It would be fairly easy to setup a dozen or more honeypots and examine
the logs in order to create an initial list.

A large percentage of those bots are in DHCP'ed cable/dsl blocks.  As such,
there's 2 questions:

Quite right, which is why ...

1) How important is it that you not false-positive an IP that's listed because
some *previous* owner of the address was pwned?

As in, dynamic ranges BL.

2) How important is it that you even accept connections from *anywhere* in
that DHCP block?

Or maybe the cool concept of white-listing known senders? :)

(Note that there *are* fairly good RBL's of DHCP/dsl/cable blocks out there.
So it really *is* a question of why those aren't suitable for use in your
application...)

Many of them are SMTP-based only. IP reputation is very limited still.

Now, all that said, back on "most are broadband users" - no longer
true. Many bots (especially in spam) are now web servers.

        Gadi.


Current thread: