Stopping Plesk Panel attacks with OSSEC

During the past few weeks I’ve noticed increased brute forcing activity on various servers that I manage and run Plesk Panel. Most of the entries look like this: - - [30/Jan/2011:07:14:19 +0100] "GET /login_up.php3?passwd=setup&login_locale=default&login_name=admin HTTP/1.1" 200 5852 - - [30/Jan/2011:07:14:19 +0100] "GET /login_up.php3?passwd=setup&login_locale=default&login_name=admin HTTP/1.1" 200 5852 - - [30/Jan/2011:07:14:19 +0100] "GET /login_up.php3?passwd=setup&login_locale=default&login_name=admin HTTP/1.1" 200 5852 - - [30/Jan/2011:07:14:21 +0100] "GET /login_up.php3?passwd=setup&login_locale=default&login_name=admin HTTP/1.1" 200 5852 - - [30/Jan/2011:07:14:21 +0100] "GET /login_up.php3?passwd=setup&login_locale=default&login_name=admin HTTP/1.1" 200 5852 - - [30/Jan/2011:07:14:23 +0100] "GET /login_up.php3?passwd=setup&login_locale=default&login_name=admin HTTP/1.1" 200 5852 - - [30/Jan/2011:07:14:23 +0100] "GET /login_up.php3?passwd=setup&login_locale=default&login_name=admin HTTP/1.1" 200 5852

The side effect of all these attacks is increased server load.

Since I already have ossec monitoring these servers the solution was quite simple. I just added a couple more rules to ossec in order to stop these attacks.

Two steps are necessary to stop these attacks:
1) Add plesk panel https log to monitor list in /var/ossec/etc/ossec.conf



2) Create some custom rules to block (and notify me) of these attacks.

<rule id="100144" level="1">
    <description>Plesk Login.</description>

<rule id="100145" level="12" frequency="3" timeframe="60">
    <same_source_ip />
    <description>Attack on plesk panel.</description>

That’s it. Ossec now monitors these files and blocks through iptables any attacks with active-response.

Example notification mail:

Received From: foo->/opt/psa/admin/logs/httpsd_access_log
Rule: 100146 fired (level 12) -> "Attack on plesk."
Portion of the log(s): - - [02/Feb/2011:20:19:56 +0100] "GET /login_up.php3?passwd=setup&login_locale=default&login_name=admin HTTP/1.1" 200 5852 - - [02/Feb/2011:20:19:55 +0100] "GET /login_up.php3?passwd=setup&login_locale=default&login_name=admin HTTP/1.1" 200 5852 - - [02/Feb/2011:20:19:54 +0100] "GET /login_up.php3?passwd=setup&login_locale=default&login_name=admin HTTP/1.1" 200 5852 perl script to measure in/out traffic in realtime

During some QoS tests on Linux I needed to measure the traffic of the system in realtime without being able to compile any new software on it. The system had already perl installed so I googled to find a script that could monitor in/out traffic of an interface. The first script I found was this:

While it’s actually doing what it says, it only runs just once. I wanted the script to run for a period of time. So I changed it a bit.
Here’s the outcome:
my $dev=$ARGV[0];
sub get_measures {
my $data = `cat /proc/net/dev | grep "$dev" | head -n1`;
$data =~ /$dev\:(\d+)\D+\d+\D+\d+\D+\d+\D+\d+\D+\d+\D+\d+\D+\d+\D+(\d+)\D+/;
my $recv = int($1/1024);
my $sent= int($2/1024);
return ($recv,$sent);
my @m1 = get_measures;
while(1) {
sleep 1;
my @m2 = get_measures;
my @rates = ($m2[0] - $m1[0], $m2[1]-$m1[1]);
foreach ('received' , ' transmit') {
printf "$_ rate:%sKB",shift @rates;
print "\n";

I’ve changed it so that it’s:
a) running continuously until someone presses ctrl+c to stop it,
b) parsing the /proc/net/dev output instead of the ifconfig output. I think this is more efficient/fast than parsing the ifconfig output.

Sample output:

$ eth0
received rate:1564KB transmit rate:71KB
received rate:1316KB transmit rate:44KB
received rate:1415KB transmit rate:48KB
received rate:1579KB transmit rate:76KB

I am sure that someone with more insight into perl than me can make it even more efficient.

You can also download a version with comments that I made so that one can make the script run for X number of repetitions instead of running until someone stops it.