Handshake needs you to do another risky job in Gray Zone Warfare. He wants to see if you can listen in on what the enemy is doing and wants you to hack multiple video cameras around Fort Narith to learn more about them.
Hacker Quest Guide | Gray Zone Warfare
The hacking locations are spread throughout Fort Narith. These are hard to reach places, especially since you have to get close to heavily secured base areas and interact with the cameras.
Since you'll be getting so close, it's a good idea to bring a friend or two with you to Gray Zone Warfare. You can also hope to find an ally who will also take out the NPCs on the base.
You need to find four hackable cameras in Fort Narith: one at the air traffic control building, the main entrance, the north entrance, and the army headquarters. Each area is heavily guarded by multiple NPCs, especially the base, which is full of them. Hopefully you'll be in and out before they notice you, but expect to trade bullets with them before you can escape. They might be trying to finish Missing Colleague Two or Neighborly Help.