Viyran

The Viyrans were a race of mysterious beings that belonged to a distant galaxy that was infamous for the creation of a variety of biological and viral weapons.

Biology
Not much is known about what the actual Viyrans look like under their white hazmat armour.

They have no real spoken language but are able to communicate psychically, through hand motions or by trying to replicate an individual's voice.

Technology
It could be speculated that the Viyrans created the Amethyst Viral Containment Station to safely store the deadly viruses that they have created. They are also capable of time travel.

History
The Viyrans dealt with and catalogued various dangerous substances such as viruses. Far in the future they were summoned to the Amethyst Viral Containment Station to remove all its samples of viruses that it had collected. They were prevented from doing so by the interference of the Daleks. (BFA: Patient Zero)

Trivia

 * They are known to have engineered the viruses featured in Urgent Calls, Urban Myths, The Vanity Box and The Wishing Beast.