Arianna Peterson is the main antagonist from "URL, Interrupted", episode 1.07 of CSI: Cyber.
She was portrayed by Ashley Jones.
Arianna Peterson is a guidance counselor and the one-time lover of Jordan Tan, the father of student Zoey Tan. Their relationship was met with immense disapproval from Zoey, which led to Jordan breaking up with Arianna out of his care for his daughter. However, Arianna was left angry and bitter over Jordan breaking up with her, while also placing blame on Zoey for her relationship ending.
She later planned revenge on both Zoey and Jordan, beginning with catfishing Zoey, doing so by copying a social media page belonging to Owen Campbell (a friend of Zoey's) and setting up a relationship between the two. The plan was to get her out of the way and in her own relationship so she could go back to Jordan.
When that failed, the evil Arianna decided to RAT (Remote Access Trojan) Zoey's computer and start a cyberbullying page, with many students responding and posting bullying messages, and even posted a message in Zoey's name that made it appear that Zoey was suicidal. The villainess committed the act using her office computer, and it was done to not only torment Zoey, but Jordan as well. She even copied Zoey's phone and called Jordan, making him believe that it was Zoey on the phone, and in the early scenes of the episode, Arianna appeared to Jordan and acted consoling towards Jordan to mask her heel persona.
Zoey was originally believed to be the target throughout the episode, but Avery Ryan realized that the perpetrator was going after Jordan, not Zoey. Daniel Krumitz and Elijah Mundo were at the school searching for the device used to cyberbully Zoey, and that led them to Arianna's office, revealing her as the villainess. Mundo confronted Arianna and exposed her as the true cyberbully, while also revealing that she was Jordan's girlfriend and that she was angry over the relationship ending. After denying it at first, Arianna admitted to everything and voiced her bitterness over Jordan choosing his daughter over her, and regarding why she would torment a 17-year-old girl, the callous villainess stated that she wanted to hurt Jordan and the best way to do so is to hurt his daughter. After this, Mundo then handcuffed and arrested Arianna for cyber fraud and aggressive stalking.