Telegraph is a miniscule computer program written in binary machine code, developed by Maurine Ellson with characteristics of both a virus and a communications program.

With a total file size of less than 1kb, it is extremely simplistic. When run, visually it consists of a small dark red circle which appears in the upper left corner of the screen at all times. A virus-like characteristic of this program is that once it is run, it embeds itself into the kernel of the operating system, such that it will always run every time the computer is started. Only a complete wipe of the system can remove it. Whenever the spacebar of a connected keyboard is pressed, the color of the circle changes from dark red to bright red. When it is run on a computer, that computer gains a peer-to-peer encrypted connection with all other computers which have run the same code. When the circle is changed to bright red by a spacebar press from any connected computer, it becomes bright red on all connected computers.

Cae Lawrence discovers this program (as a *.bin file) on the flash drive recovered by Frost Lawrence during their infiltration of Murphy Labs.