#1575 – please explain about - UserAgent black list + IP black list

 if i want black list a range of IP adresses will the wildcard work ?
199.27.*.*

how to black list an empty UserAgent ?

when the UserAgent containts multiple words - is it enough to write only one in the UserAgent black list ?
when the useragent looks like perl code and is like one long big word is it enough to write only few letters(word that makes sense)

ok, thanks

another question, i have ossec hids installed - is a monitoring software

and it triggered an alert, in the end is sh404sef too, any idea what this is about

Received From: try-wild->/var/log/apache2/error.log
Rule: 1002 fired (level 2) -> "Unknown problem somewhere in the system."
Portion of the log(s):

[Mon Dec 21 05:52:39.865328 2015] [:error] [pid 7141] [client 59.46.158.24:36675] PHP Notice: Undefined index: HTTP_HOST in /var/www/html/libraries/joomla/application/web.php on line 863

--END OF NOTIFICATION

OSSEC HIDS Notification.
2015 Dec 21 05:52:41

Received From: try-wild->/var/log/apache2/error.log
Rule: 1002 fired (level 2) -> "Unknown problem somewhere in the system."
Portion of the log(s):

[Mon Dec 21 05:52:39.892238 2015] [:error] [pid 7141] [client 59.46.158.24:36675] PHP Notice: Undefined index: HTTP_HOST in /var/www/html/libraries/joomla/uri/uri.php on line 85

--END OF NOTIFICATION

OSSEC HIDS Notification.
2015 Dec 21 05:52:41

Received From: try-wild->/var/log/apache2/error.log
Rule: 1002 fired (level 2) -> "Unknown problem somewhere in the system."
Portion of the log(s):

[Mon Dec 21 05:52:39.900429 2015] [:error] [pid 7141] [client 59.46.158.24:36675] PHP Notice: Undefined index: HTTP_HOST in /var/www/html/administrator/components/com_sh404sef/classes/pageinfo.php on line 256