A mobile security system, comprising: a mobile security system processor; a preboot memory configured to store at least a portion of an operating system of the mobile security system; a runtime memory configured to receive a copy of the at least the portion of the operating system from the preboot memory when the mobile security system is rebooted; a connection mechanism configured to connect to a data port of a mobile device and to communicate with the mobile device, the mobile device having a mobile device processor different from the mobile security system processor, the connection mechanism configured to receive a network connection request from the mobile device, when the mobile device is outside a trusted network (315, 340) the mobile security system configured to determine, based on a security policy, whether to forward network data intended for the mobile device and received from a network to the mobile device; a network connection module configured to act as a gateway to the network; the security policy including a security attribute configured to force network connection through the mobile security system when outside the trusted network (315, 340) and to cause all network connections by the mobile device other than through the mobile security system to be closed when the mobile device is not resident on the trusted network identified by the security policy, and configured not to cause all network connections other than through the mobile security system by the mobile device to be closed when the mobile device is resident on the trusted network; and a security engine configured to execute, in the runtime memory, the security policy a mobile security system processor; a preboot memory configured to store at least a portion of an operating system of the mobile security system; a runtime memory configured to receive a copy of the at least the portion of the operating system from the preboot memory when the mobile security system is rebooted; a connection mechanism configured to connect to a data port of a mobile device and to communicate with the mobile device, the mobile device having a mobile device processor different from the mobile security system processor, the connection mechanism configured to receive a network connection request from the mobile device, when the mobile device is outside a trusted network (315, 340) the mobile security system configured to determine, based on a security policy, whether to forward network data intended for the mobile device and received from a network to the mobile device; a network connection module configured to act as a gateway to the network; the security policy including a security attribute configured to force network connection through the mobile security system when outside the trusted network (315, 340) and to cause all network connections by the mobile device other than through the mobile security system to be closed when the mobile device is not resident on the trusted network identified by the security policy, and configured not to cause all network connections other than through the mobile security system by the mobile device to be closed when the mobile device is resident on the trusted network; and a security engine configured to execute, in the runtime memory, the security policy