How to fix the issue
The "This site my harm your computer" label will not be removed until the webmaster of the site takes action. Below are some suggestions on ways to resolve this issue if it is happening to your site:
Register and verify your site in Google’s free Webmaster Tools.
Sign in to Webmaster Tools and check the Security Issues section to see details of sample URLs that may be infected.
Read our resources for hacked sites for detailed information on how to fix your site.
Remove the malicious content from your site.
Fix the security issue that allowed your site to be infected. Otherwise, your site is likely to be reinfected.
Request a review in the Security Issues section in Webmaster Tools when your entire site is clean and secure. Once we determine your site is fixed, we will remove the malware label.
Well it seems that the images coming from here: /forum/imagini/sageata2.gif don't work properly.
But the same image from here: /imagini/sageata2.gif work fine.
Did you move your forum from the public_html folder to the forum folder??