Abstract: A computer worm defense system comprises multiple containment systems tied together by a management system. Each containment system is deployed on a separate communication network and contains a worm sensor and a blocking system. In various embodiments, the computer worm may be transported from a production network, where the computer worm is not readily identifiable, to an alternate network in the worm sensor where the computer worm may be readily identifiable. Computer worm identifiers generated by a worm sensor of one containment system can be provided not only to the blocking system of the same containment system, but can also be distributed by the management system to blocking systems of other containment systems.