site closed suddenly

hi when i open my site it closed suddenly and when i open it for the second time it opens normally and the problem is that google has put warning massege under my site in the search
This site may harm your computer.

i don't know where is the problem??

 

Have you recently added anything to your site, given access to anyone or anything like that?

 

someone help plz the site closes itself on time after opening it and when open it again it works in normal way

 

yes i have installed script and i had doubt it was the reason so i deletedf it but the problem hadn't been solved

 

you will need to add that site to your webmaster tools account and then ask them to unblock it.
The reason for the block could be either one of your scripts that google sees as malicious or your pc is infected and someone keeps inserting encrypted code to your index page because they know your ftp password (spyware zBot).

check the source code of your index page and see if you can find any encrypted code at the bottom of your page

 

Check your footer and see if there is any suspicious code

 

Check for codes that may look dangerous or contact google and ask what code is bad.

 

Try this site, it can scan your site for virii

http://online.drweb.com/

 

have you tried to open the site from other computer, does it do the same.

 

maybe hosting.. if not the script and content

 

call your hosting admin..and they will solve your problem

 

Its a case of distributing malware.
I suggest you to check it with Google Safe Browsing and then take the necessary actions.

(Replace YourDomain with your domain name.

 

I think your site have virus affected. So, check your site very closely if there is an script that is not using in site but have. Remove it and again upload it. Below url may help you more.

http://www.google.com/support/forum/p/Webmasters/thread?tid=71b973430821550b&hl=en

 

I have noticed that there is a folder in public html root belongs to a script and whhen i try to delete it and make refresh the folder appears again and i think it is the reason

 

if you have full backup for your files and db buy new hosting and upload all your files and db

 

also some time, it may due to harmful advertisement that contain malware/virus.
Some time, AVG used to show harmful content available in Techcrunch pages.

 

Try another hosting or check this site with anti-virus and find out where is the mistake.

 

call your hosting they will solve i think

 

Most likely an iframe at your header. Take a look and see if there are any suspicious codes. After that request for recheck at Google webmaster.