A user authenticates a mobile device (MD) to a network-based service (NBS) for initial authentication. Policy is pushed from the NBS to the MD and the MD automatically obtains details about devices and attributes that are near or accessible to the MD in accordance with the policy. The details are pushed as a packet from the MD to the NBS and multifactor authentication is performed based on the details and the policy. If the multifactor authentication is successful, access privileges are set for the MD for accessing the NBS and perhaps for accessing local resources of the MD.