I like your action movie logic... "It's digital, it's noticably broken, it's close to the Pentagon, it must be a cyber attack!". If I were the enemy, and I wou

I like your action movie logic... "It's digital, it's noticably broken, it's close to the Pentagon, it must be a cyber attack!". If I were the enemy, and I would think the enemy would have people at least as competent as me, and somehow hacking the walk sign is relevant to the misson, I'd test the attack quietly and on a similar system but nowhere near the conspicuous final target, and maybe use an audio file you wouldn't notice is different if you weren't paying attention. Something like have the machine say "streetah" instead of "street"