Thellas
From The Stargate Omnipedia
Tok'ra operative who assessed the disabling of Stargate functionality across known space. After several hours, Thellas reported to the S.G.C. that the entire gate network was down following the deployment of Jay Felger's "Avenger" computer virus.
KEY EPISODE
Avenger 2.0 - Thellas reports information regarding the Stargate network to the S.G.C., learning that the entire known gate system has been disabled.