In you’re using Internet Explorer 7, there are several enhanced and tightened security features that have been incorporated into IE7. One of them being restricted Clipboard data access by websites and web pages.
In Internet Explorer 7, both IE 7 installed on Windows XP or IE7 that comes with Windows Vista, the behaviour occurs when you visit a website or webpage that tries to access the information stored in Clipboard’s memory…and, as Clipboard’s memory stored data can be sensitive and private, for security purposes, IE7 will pop-up a warning alert message as below:
Do you want to allow this webpage to access your Clipboard?
If you allow this, the webpage can access the Clipboard and read information that you’ve cut or copied recently.
You will then need to press or click “Don’t Allow” or “Allow” button to get past the popup message.
This security feature can be disabled if you are annoyed by it, but you should consider that if you do, web sites that want to steal your information will do so without warning you beforehand.
How can you be certain that this is not something that penetrated your web server which services your web site account? Are you the administrator of the web server? If so, you should scan the files and update the software/hardware to tighten up any exploits…if not, you should most certainly contact the administrator of that web server to notify them of the intrusion into your web site that you did not authorize.