The Medusa Bug
The Medusa was a small viral bug contained in a hand held box. The Medusa was created by Hexadecimal. Megabyte started working with Hex for a short time in order to steal the Medusa from her. He was successful in smuggling the box out of the Lair. Hex brought Nulls to stop him but Hack and Slash broke the bridge to Lost Angles severing it from Mainframe. Megabyte and escaped back to Silicon Tor by leaving a small group of ABCs to try and stop Hex. She easily destroyed them with minimal effort. (The Medusa Bug)
Mainframe being infected
Megabyte didn't realize that Hex purposely let him take it so that he would activate the viral bug away from her island. When he opened the box it immediately infected his hand turning it to stone and traveling up his arm. His computer was unable to identify the bug and couldn't come up with a cure. Hex taunted him in his last moments revealing her trap to him. The Medusa infected the Tor quickly and moved on to the rest of Mainframe. Bob tried to use a powered-up viral erase command on the bug, but it was too powerful to be erased and resisted the command.
Medusa surrounding Frisket
Phong evacuated the city's inhabitants to the Principal Office and put up its shields. The Medusa quickly degraded the shield and infected the Principal Office and everyone in it. The only one to survive was Bob; his guardian code made him immune.
Principal Office being infected
Bob decided to go to Lost Angles and tried to exact his revenge by infecting Hexadecimal with the Medusa. When he arrived at Hexadecimal's Lair, Hex had decorated her Lair with infected Mainframers, even Scuzzy had been infected.
Hex and infected Scuzzy
Hex had no trouble stopping Bob and was ready to destroy him when he thanked her for making Mainframe so quiet and predictable, with no one moving or changing. When Hex realized how peaceful it would be in Mainframe, which worked against her chaotic nature, she snapped her fingers, and the entire city was immediately restored to normal. Rather than in an episode, this story was told in clips in areas where Superhuman Samurai Syber Squad briefly rain in ReBoot's time slot.
Phong Infected
Dot and infected Binomes
Soon after Hexadecimal removed her Medusa, Megabyte created a similar but weaker version of the Medusa Bug. Bob asked Hex to help remove it but she liked the chaos her brother was making. Phong contacted Bob and told him that this version of the Bug could be destroyed by a Trias Effect.Bob eventually left Mainframe after it was completely turned to stone. He went to the Super Computer where he found the Trias Effect. He returned to Mainframe and erased the Medusa Virus.