I am continuing to search for further issues and will keep you informed. I will do what I can to increase security and prevent further issues. It may take a few days for the site to become unblocked and browsers to declare us clean again.
Apologies for the inconvenience caused.
Scanning your PC for threats
If you wish to scan your PC for threats as a precaution and don't have an existing application to do this, I would recommend the free tools:
Malwarebytes (anti-malware): http://www.malwarebytes.org/
Avast (anti-virus): http://www.avast.com/
Both also provide paid for solutions with extra features however the free versions should be able to find most issues on a home PC.