1. At least one machine accessible storage medium having code stored thereon, the code when executed on a machine, to cause the machine to: receive a download of software; determine, from the download, a digital signature of the software; determine, from the digital signature, whether the digital signature corresponds to a trusted source; prevent unauthorized execution of the software by causing the machine to: query a browser to determine whether a selected uniform resource locator (URL) to which the browser was pointed for the download of the software is authorized; and based on determining that the selected URL is not authorized: display a message indicating that the selected URL is not authorized when the software is invoked for installation; and prevent installation of the software; and based on determining that the selected URL is authorized: install the software, wherein determining whether to install the software is further based on whether the digital signature corresponds to the trusted source.