System Peril Distributed Reflex

The System Peril Distributed Reflex (or SPDR, pronounced "spider") is an automated program placed in UNSC AIs to assist the AI in repair when it becomes too damaged to function properly on its own.

I Love Bees
When a temporal rip caused Melissa to crash into the ilovebees server in 2004, her SPDR repaired her greatly and fought to remove the threat of the Seeker, a malicious Covenant AI, eventually succeeding. Before it did, however, the Seeker absorbed the SPDR's language and impersonated it.

Melissa was too damaged to tell the difference and temporarily disabled the real SPDR, allowing the Seeker to corrupt her. When the rip closed and sent her back home, the Seeker and the SPDR were left alone in the ilovebees server. The SPDR killed the Seeker and prepared the server to keep it functional for 500 years until October 9, 2552, at 06:07:00, until it could send itself and the information it had gathered to UNSC forces.

The Widow
A fragment of Melissa called the The Sleeping Princess communicated the SPDR's (whom she called the Widow) story through corrupted image files that were taken and pieced together to create the narrative of The Widow's Journey.