The Shadow Virus is the Secondary Antagonist of Skip and Sqak Rangers. It is a rogue robot built by Lisa for her own use while secretly working for the Red Ants to borrow some of their technology to build a giant robot to destroy Sunny City.
The Shadow Virus can also reprogram Blue Ceterians to attack the Blue Ants. It was unknown if it was either Melvin or the Red Ants who built it, until it turns out it was actually Lisa who made it.
While working as a mole for the Red Ants, Lisa created an army of robots to attack the city. Lisa users her creativity to create her own robotic assistant nicknamed Shadow Virus which she can use to hack Ceterians (Red or Blue) to obey her. The Shadow Virus is than used to sabatoge many electronics (such as the SSFF Transport Device, Ceterian Hives, etc). Later, the Virus dropped Cy-Bots down the pipes to sabatoged the SSFF's Transport Device.
The SSFF thought the virus had no one in it, until they found out it's Robin's best friend Lisa, who some how came to see Roshan and the Blue Ants as a minor influence in the two girls friendship as Lisa wants to defend the world with her own technology.. Later, the SSFF went to the junkyard and destroyed Lisa's giant robot before she uses it to destroy the whole Sunny City.
After an explosion from the giant robot, the SSFF found themselves surrounded by flames with the Shadow Virus (with Lisa inside it). Lisa was about to kill Roshan for getting in the way of her and Robin's friendship, but The SSFF fought and defeated the Virus, who completly damaged from the battle explodes (not before ejecting an unharmed Lisa).