The multi-agent program can also send out probes to locate and assess its attacker. For example, it replaces old agents by fresh agents periodically. This ensures that hacked systems are flushed eventually and must be re-hacked to be compromised. In fact it's so sophisticated it's almost life-like. Once it's born, it connects immediately to other agents and becomes a member of the security community.
Resistance certainly appears to be futile.
The cyberagents' ability to respond quickly when faced with a vast number of attacks and to colonise new territory even more quickly means it's not only an improvement on old virus scanners, in a purely computer security sense, it's an improvement on people. Humans aren't fast enough. A person sitting at a terminal cannot protect you from Internet attack that is coming from everywhere in large masses of data. On command, they can be made to act as a supercomputer to attack a target, as happened recently, or crack a privacy code intended to protect financial, medical, or other critical data. In time the agents may graduate from patrol to control.