Mass Injection Site

I'm new to this community and I was wondering if anyone could help.

 

I created www.derrington.org.uk for our local Millennium Green project. It has always been a basic site but has always worked fine. During the last 24 hours however, it has suddenly stopped working, with NIS2012 saying it is a 'Mass Injection Site' and refusing to go further. Not only that but a colleague of mine using Kaspersky is having a similar problem with the site only being told it has a Trojan (he hasn't said which one). I've had the site checked by an expert technical architect who assures me that the site is problem free. his credentials are unquestionable, he writes code for the BBC weather site.

 

Can anyone give me ideas about how to solve this dilemma...the site works perfectly when using Linux. Weird methinks!

 

jovisgoesnuts