An Evolutionary Strategy for Resilient Cyber Defense

Many cyber attacks can be attributed to poorly configured software, where administrators are often unaware of insecure settings due to the configuration complexity or the novelty of an attack. A resilient configuration management approach would address this problem by updating configuration settings based on current threats while continuing to render useful services. This responsive and adaptive behavior can be obtained using an evolutionary algorithm, where security measures of current configurations are employed to evolve new configurations. Periodically, these configurations are applied across a collection of computers, changing the systems´ attack surfaces and reducing their exposure to vulnerabilities. The effectiveness of this evolutionary strategy for defending RedHat Linux Apache web-servers is analyzed experimentally through a study of configuration fitness, population diversity, and resiliency observations. Configuration fitness reflects the level of system confidentiality, integrity and availability; whereas, population diversity gauges the heterogeneous nature of the configuration sets. The computers´ security depends upon the discovery of a diverse set of highly fit parameter configurations. Resilience reflects the evolutionary algorithm´s adaptability to new security threats. Experimental results indicate the approach is able to determine and maintain secure parameter settings when confronted with a variety of simulated attacks over time.