Apache compromised

Hi,

In my apache2 error logs I noticed that a script is automatically being downloaded and run. Due to this the cpu usage goes to 100% when this perl script runs. I checked http://brk1.home.ro/perl in my browser and it shows the perl script which shows that it is a LinuxNet perlbot. Inside the script there's a mention of an IP: 209.114.36.218 to which it tries to connect. Now this IP belongs to slicehost and some time ago before moving to linode I was with slicehost.

Please have a look at my apache error log snippet below. I've checked my older logs and this same snippet shows once in a while -

--2011-12-06 08:00:45-- http://brk1.home.ro/perl
Resolving brk1.home.ro... --2011-12-06 08:00:45-- http://brk1.home.ro/perl
--2011-12-06 08:00:45-- http://brk1.home.ro/perl
Resolving brk1.home.ro... Resolving brk1.home.ro... --2011-12-06 08:00:45-- http://brk1.home.ro/perl
Resolving brk1.home.ro... 81.196.20.133
Connecting to brk1.home.ro|81.196.20.133|:80... 81.196.20.133
Connecting to brk1.home.ro|81.196.20.133|:80... connected.
HTTP request sent, awaiting response... connected.
HTTP request sent, awaiting response... 200 OK
Length: 16186 (16K) [text/plain]
Saving to: `perl.1'

0K ..200 OK
Length: 16186 (16K) [text/plain]
Saving to: `perl.1.1'

0K ................ ..... 100% 49.4K=0.3s

.. ..... 100% 48.3K=0.3s

2011-12-06 08:00:46 (48.3 KB/s) - `perl.1.1' saved [16186/16186]

2011-12-06 08:00:46 (49.4 KB/s) - `perl.1' saved [16186/16186]

I believe that this is related to apache but I am don't know how this perl script is being automatically downloaded and run.

Any help would be greatly appreciated.