Keep your computer and browser up-to-date and virus-free
Keep your browser and Operating System updated with the most current versions and patches; patches are often released to address particular security threats. Be sure to also scan your computer regularly for viruses, spyware, and adware.
If you're using a public computer, make sure you always sign out of ENMAT when you're done (there's a "logoff" link in the upper right of the site).