|"Conceal your presence at the DataSec break-in from Mayfield."|
This achievement can be unlocked in the post-mission dialogue in Mayfield: The DataSec Recording.
If Conway didn't walk into the camera's vision in Rooke: Three for All, then sending either the real data or random garbage will unlock this achievement.
If the camera in Three for All did see Conway, then sending random garbage will unlock the achievement.