Kiran,

Usually Google has found software that should not be there.

Somehow they got to the webserver and changed some files.

So first change your password to your webserver. Then remove all software. from your webserver. (maybe make a backup but be carefull some files might be changed)

Then upload your website again.

Hopefully this helps,

BR A

May be it would, but changing and uploading the website is a task that will be too much time consuming, given the size of the website.

Then there is another option. Check out the files on the webserver and see if any of them are changed (check on date). The should all be the same data from the latest update.

usually 1 file stands out, then you could replicate the site on hd and just update that one file.

Goodluck.