Illuminae (The Illuminae Files, #1)

Kady thought breaking up with Ezra was the worst thing she'd ever been through. That was before her planet was invaded. Now, with enemy fire raining down on them, Kady and Ezra are forced to fight their way onto one of the evacuating craft, with an enemy warship in hot pursuit.
But the warship could be the least of their problems. A deadly plague has broken out and is mutating, with terrifying results; the fleet's AI, which should be protecting them, may actually be their biggest threat; and nobody in charge will say what's really going on. As Kady plunges into a web of data hacking to get to the truth, it's clear only one person can help her bring it all to light: Ezra.
Told through a fascinating dossier of hacked documents--including emails, schematics, military files, IMs, medical reports, interviews, and more--Illuminae is the first book in a heart-stopping, high-octane trilogy about lives interrupted, the price of truth, and the courage of everyday heroes.