Intel are hidden collectibles in the single player portion of Halo 5: Guardians. Finding them all will unlock the Hunt the Truth Achievement.
The second mission, Blue Team, contains eight of them. This guide will show you where to find intel in Mission 2: Blue Team.
Intel #1: Argent Moon Station Warning
You’ll find a glitched out terminal after the opening, across from the bridge. Activate it to get the intel.
Intel #2: Log: 2557-3-17 1231 SMT 1/4
After the fight in the first bay, go to the right, past the weapons rack. You’ll see another control point terminal, flickering and glitching out like the last. Activate it, and you’ll receive the intel.
Intel #3: Test Results Asteroidea 59B
When you get to the Central Control door, turn right and climb up the platforms until you can climb no more (3 stories). There will be a data pad on the large platform.
Intel #4: Test Results Asteroidea 61F
In the Level 3 area, go left until you find a stack of metal crates. You can either make top them over by doing a melee attack, or jump over them. There’s a vent behind, which leads to a small room where the data pad is.
Intel #5: Log: 2557-3-19 1653 SMT 2/4
At some point, you’ll pass through a giant corridor with large windows on both sides, ending with a round door. As soon as you pass through the door, you’ll see an intel terminal in front of you.
Intel #6: Test Results Asteroidea 472A
While you’re riding the elevator in the Hunter room, you’ll see the next piece of intel. It’s on a data pad on the floor below, on the left side of the room, next to a body.
Intel #7: Log: 2557-3-19 1654 SMT 3/4
After that, you’ll enter a large room with 4 round devices on the floor. The control point terminal is to the left of them, in the corner.
Intel #8: Log: 2557-9-12 613 SMT 4/4
You’ll find the final piece of intel on your way to the hangar. When you pass a door jammed by a metal crate, you’ll see a terminal in front of you. Activate it to get the intel.