Do you know that web sites you visit can retrieve data from your clipboard depending on your security settings. Regular users use it routinely to copy and paste information such as passwords and credit card numbers from one form to another.
Just checkout this site(projectip.com) on Internet explorer for getting the current details of your clipboard.But the clipboard contents could be viewed only with Internet Explorer.(Firefox rulez!! LOL)
How To Fix this Security Bug.
Fix: Go to Tools > Internet Options > Security > Select a security zone > Custom Level > Scripting > Allow paste operations via script and set it to Disabled or Prompt.
Read full story at TrapBot security blog