In an example embodiment herein, there is provided methods and a system for cloud-assisted threat defense for connected vehicles. A vehicle suitably includes an on-board computer system for operating and/or controlling various systems on the vehicle. The on-board computer system suitably operates in connection with or includes an on-board threat defense module for detecting and protecting against malware attacks and other security threats to the vehicle. In an example embodiment, a cloud-based security component or security cloud assists with the detection and protection against security threats and malware attacks to the vehicle while minimizing the processing load and memory requirements for the on-board threat defense module.