1. A method of secure scanning of a second web page linked to a first web page being displayed by a browser in a browser window, the method comprising: identifying, in the first web page, a target link to the second web page, wherein the target link is identified from one or more links that are contained within the first web page, wherein the one or more links are prioritized by a client computing device based on a location of the one or more links in the first web page to determine a prefetching order, and wherein the target link is identified and prioritized before a request for content of the second web page is sent from the client computing device to a computing device that stores the content of the second web page; prior to receiving a user selection of the target link or of an indicator associated with the target link, prefetching content from the second web page, the content including web page data, applets, or scripts; loading the prefetched content from the second web page into a safe cache on the client computing device according to the prefetching order before receiving the user selection of the target link or of the indicator associated with the target link and before the content of the second web page is opened by an application configured to provide access to the content of the second web page on the client computing device; and scanning the prefetched content from the second web page for a security threat, within the safe cache, wherein the safe cache is configured to prevent the prefetched content from altering a memory location or storage location external to the safe cache.