Time: June 19th 2009 17:40:00(CEST)
Dear Customer,

There has been a public release of a Apache DoS tool.
You can read about it on the following URL’s

http://isc.sans.org/diary.html?storyid=6601

All versions of Apache are vulnerable.
There are a couple of solutions, one of them is limitipconn
http://dominia.org/djao/limitipconn2.html
However we have found it does not work as it should on all distributions.

We have put together a quick shell script that should give you protection in case your server is being attacked.

It currently is a crude version, if you see it does not work on your server please contact our support and we will try and get it working for you.

If you suspect your server is being attacked you can download the following to your linux webserver. This script does not work on BSD or windows.

http://www.leaseweb.com/antiloris.sh

Place the file in some directory and make it executable.

# wget -O /usr/local/sbin/antiloris.sh http://www.leaseweb.com/antiloris.sh
# chmod 755 /usr/local/sbin/antiloris.sh
# echo “* * * * * /usr/local/sbin/antiloris.sh” >> /etc/crontab

Then edit the file.
In the beginning of the file there are a couple of variables:
LIMIT=50
[email protected]
SENDEMAIL=1
RESTARTAPACHE=1

LIMIT is used for the amount of sessions the attacker has to open before his IP address will be blocked.
EMAILADDRESS is the email address you want to receive email alerts on
SENDMAIL can be 1 or 0. Set to 0 to no longer receive email.
RESTARTAPACHE This variable can restart apache after the IP address has been blocked. Some customers may not want to restart their apache after eac attack, but wait for regular apache time-outs.