The story follows Ben, Gwen, and Grandpa Max as they track down a "digital ghost" of Retaliator that has infected Bellwood’s power grid. To delete the virus, Ben has to do something he’s never done: he must "download" himself into the city’s mainframe.
It looks like you're referring to the animated film (released in 2012).
Ben (in Tetrax's body), Gwen, and Grandpa Max rally to defend the planet. The stakes are raised when Malware absorbs the Retaliator, gaining massive size and power, evolving into a terrifying, monstrous version of himself. He becomes so large that he literally towers over the planet.