Text/Javascript created malware? How?

[David Copeland]

The following script got installed on our web site without our knowledge or approval:

<script type="text/javascript" defer src="GKFD.js"></script> 

Any idea what the script does? The effect was that our web page did not load up and all we got was white. I removed it, but I am trying to find out how it happened, where it happened, and what I can do to prevent it next time.

Thanks

[Jose Amaral Rego]

Host provider will tell you if unauthorize access was gain and what was added.