The U.S. Department of Homeland Security is advising people to temporarily disable the Java software on their computers to avoid potential hacking attacks.

The call came in response to the discovery of a new vulnerability that lets an attacker execute code on a PC running Java. The vulnerability is reportedly already being used in 'exploit kits' which are pre-packaged, for-sale tool kits that can be used to commit online crimes such as stealing someone's identity.

Security experts have been advising people to disable Java for some time, since it is so commonly targeted by cyber criminals.

Turning off Java can be done in a few simple steps, depending on which browsers you use.

Mac owners who use Google Chrome can go to Chrome://plugins and verify that the Java plugin is disabled. If you use Safari, you can choose Safari>Preferences, click security and uncheck the box that says 'enable Java.' If you use Firefox, you can choose Tools>Add-ons, search 'My add-ons' and disable any Java plugin.

Windows users can find out how to disable/uninstall Java here.