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Date: Mon, 3 Oct 2005 12:48:21 -0400
To: Clemens Renner <claim@rinux.net>
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Cc: freebsd-security@FreeBSD.ORG
Subject: Re: Repeated attacks via SSH
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<<On Mon, 03 Oct 2005 13:00:33 +0200, Clemens Renner <claim@rinux.net> said:

> Failed password for illegal user qscand from 217.20.119.212 port 50657 ssh2

I modified my version of /etc/periodic/security/800.loginfail to
filter out all the "illegal user" messages from sshd; otherwise I
would be getting about 24,000 lines of crap a night in my security
report (3,000 attempts per host times eight hosts).  Since all of the
machines I care about have very limited access, I don't lose anything
by not overwhelming my security mail with unimportant failures.

I also aggressively use AllowUsers/AllowGroups in sshd_config to limit
exposure even more.  (That way, I don't have to see all the failures
for "www" and "pgsql" as well.)

-GAWollman