Abstract: A security system provides a defense from known and unknown viruses, worms, spyware, hackers, and social engineering attacks. The system can implement centralized policies that allow an administrator to approve, block, quarantine, and log file activities. A server associated with a number of hosts can provide a query for host computers to access security-related meta-information in local host stores. The query is pulled from the server by the hosts. The results of the distributed host query are stored and merged on the server, and exported for display, reports, or security response.