The "about:blank" is one of the implementations of the "about" Uniform Resource Identifier (URI) scheme for Web browsers. The "blank" token shows the Web browser's representation of a blank HTML page.
Web browsers utilize the "about" URI scheme to display internal processes and functions. For instance, "about:labs" shows the experimental features of the Google Chrome browser. Developers also have Easter eggs and other hidden features in their browsers that only appear when users enter certain "about" tokens in the address bar. Although "about:blank" only references a blank page, this URI scheme is susceptible to scripts. Hijackers often exploit vulnerabilities in URI schemes to take over the user's browser and redirect him to a malware-infected website.