Transformers Prime Episode #13 Sick Mind

Ratchet detects the Decepticon ship but also detects an emergency Autobot signal on the same frequency. Optimus and Ratchet go to check out the signal and they find all the Autobots on the ship have perished. Ratchet finds that all the Autobots on the ship perished from an ancient Decepticon virus. Optimus becomes infected by some infected energon.