For decades, satellites, drones, and human spotters have all been part of war’s surveillance and reconnaissance tool kit. In an age of cheap, insecure, Internet-connected consumer devices, however, militaries have gained another powerful set of eyes on the ground: every hackable security camera installed outside a home or on a city street, pointed at potential bombing targets.

On Wednesday, Tel Aviv–based security firm Check Point released new research describing hundreds of hacking attempts that targeted consumer-grade security cameras around the Middle East—with many apparently timed to Iran's recent missile and drone strikes on targets that included Israel, Qatar, and Cyprus.…