I get that warning on both Fx26 and IE8, searching on google.com and google.com.au. My query was:

https://www.google.com/search?q=site%3Athedepression.org.au

For assistance with this message, try Google's support here:

• About malware and hacked sites - Webmaster Tools Help
• http://productforums.google.com/forum/#!categories/webmasters/malware--hacked-sites

Sorry to hear this news. It is something you need to investigate further.
I suggest you look at and follow the information on the Google page

• https://support.google.com/websearch/answer/190597?p=ws_hacked&rd=1

It is Google that is responsible for the listing.

I tried myself with Google.co.uk and Google.com from both Firefox and Chrome. All four searches flag your site as hacked.

If I ignore the warning from Google I am still able to open your site without any specific Firefox warning

• i.e. I do not yet get something similar to THIS
  

You may also be interested in

• How does built-in Phishing and Malware Protection work?#w_what-is-an-attack-site-what-is-malware and the additional links from that page including
  • http://stopbadware.org/
  • http://code.google.com/p/google-safe-browsing/wiki/Protocolv2Spec

I hope the links and information enable you to solve your problem.

It is very shocking when your site gets hacked. I had very bad experience like you. I am very sorry for you. When my website get hacked i have scanned my website using (paid for services)* and i got to know the site is get hacked. later i tried to download the files and clean it but i could not able to do it by myself. later i took ----* professionals help. They have fixed my site in a day. Now they are monitoring and maintaining my website , using ....* website protection tool. It is Awesome experience with them.

* Edit  & comments by a forum  moderator, ~J99 

• Removed display of links and names to professional and paid for services and products.
• We mainly deal with Firefox end user problems here not Website issues.
• The usefulness of such a scan may be rather speculative, and then advertises additional paid for services.

Glad you fixed our own problems with your website, but the details of that are rather out of the scope of this forum. Specialist Security fora may be able to offer advice or discussion. For instance

• Bleeping Computer Forums
• Spyware Warrior Forums
• SWI Forums