Information about Feature chmod to 0 malware script

[yak983]

Hello,
it's possible have more information about this feature?
http://www.directadmin.com/features.php?id=1636

i have add into directadmin.conf the follow value:

parse_php_mail_log_at_limit=2
disable_php_script_at_limit_threshold=60
disable_php_script_at_limit_minimum=400

but it don't work .. can be limit 0 value in the /etc/virtual/limit ?

any idea?