1. A method for protecting a browser from malicious processes, comprising: providing, responsive to determining that a request received by the browser was sent by a process that is external to the browser and any plug-ins of the browser a browser-proxy object to the process in response to the request; and providing a process-proxy object interposed between the browser and the process, wherein the browser-proxy object is configured to cause the process to send to the browser-proxy object a subsequent request that the browser perform an action involving Document Object Model (DOM) data maintained by the browser, and decide whether to allow the action to be performed, and wherein the process-proxy object is configured to receive from the browser any events for forwarding to the process, and decide whether to forward any of the events to the process.