Cyber warfare is asymmetric in the current paradigm, with attackers having the high ground over defenders. This asymmetry stems from the situation that attackers have the initiative, while defenders concentrate on passive fortifications. Defenders are constantly patching the newest hole in their defenses and creating taller and thicker walls, without placing guards on those walls to watch for the enemy and react to attacks. Current passive cyber security defenses such as intrusion detection, anti-virus, and hardened software are not sufficient to repel attackers. In fact, in conventional warfare this passivity would be entirely nonsensical, given the available active strategies, such as counterattacks and deception.Based on this observation, we have identified the technique of booby trapping software. This extends the arsenal of weaponry available to defenders with an active technique for directly reacting to attacks. Ultimately, we believe this approach will restore some of the much sought after equilibrium between attackers and defenders in the digital domain.