GEN:SID 1:256
Message DNS named authors attempt
Summary An attempt was made to query authors.bind chaos record on your DNS server.  
Impact Allows a remote attacker to possibly determine the version of bind
you are running.
Detailed Information Bind 9.x allows you get the authors.bind chaos record.  The ability to
retrieve this file indicates that the machine is running at least a
9.x variant of the bind nameserver.
Affected Systems  
Attack Scenarios As part of a reconnaissance mission, an attacker may attempt to gleen
important information about your infrastructure by determining your
bind version.  If authors.bind is retrievable, this indicates that you
are running Bind 9.x.  If not, it means nothing.  This, in addition to
possibly retrieving version.bind, allows attackers to craft attacks
specially suited for your environment.
Ease of Attack Trivial:

warchild@cuba
[~]$ dig +short @testhost.com txt chaos authors.bind

"Bob Halley"
"Mark Andrews"
"James Brister"
"Michael Graff"
"David Lawrence"
"Michael Sawyer"
"Brian Wellington"
"Andreas Gustafsson"

Corrective Action Remove the ability to retrieve the authors.bind chaos record by either
applying the patch from ISC or tweaking your configs accordingly.
Additional References  
Rule References arachnids: 480
nessus: 10728