REF070507 is an enigmatic picture contained in Server 05.
Its exact origin is unknown, although presumably it is of Forerunner origin. It is titled "Flood Containment Control Infectious Study REF #070507," and appears to have a high-resolution micrograph of what appear to be microbes, presumably of Flood origin. In the bottom left hand corner is the text "CNO DR54 G 48." Along the bottom surface is a rectangular tab, and on the left side is the text "CnRL - Infc," presumably referring to the control group (CnRL) and the experimental group (Infc), two integral components to the "infectious study" experiment being photographed. In the centre of the tab there is a dot, and on the right hand side there is the text "HR 568."
Just off centre of the photograph is an amorphous blob filled with small circles. This has been hypothesized to be a cell infected with an obligate intercellular parasite, just as a virus, very possibly related to the Flood. Surrounding this cell in a half-circle arc is a rim-like structure.