Three teams from Fairfax County schools swept the top prizes at the finals of a national cyber-warfare competition last Friday.

In the CyberPatriot finals, Team Void from the Chantilly Academy won the open division of the challenge, followed by two teams from Marshall Academy in Falls Church. The competition, sponsored by Northrop Grumman, attracted more than 1,200 teams in the CyberPatriot challenge that started in November. At National Harbor last week, teenagers from around the country made up the 28 teams that met for the finals.

The winners from Team Void included seniors Chris Kim, Weyland Chiang and Brian Nguyen, and juniors Anirudh Bagde and Timothy Rothschild.

In the finals, the students worked against a time limit to defend a computer network. The students had to fix vulnerabilities in the system while fending off attacks from cyber professionals. The team from Chantilly Academy did so with ease. During a qualifying round last November, the computer wizards finished the challenge — designed to last six hours — in 38 minutes.

The runner-up team from Marshall Academy included C.J. Gardner, Alex Handley, Kevin Houk, Jack Lynch, Ramon Martinez-Diaz and Peter Morrissey. The third-place Marshall Academy team included Sepehr Ansaripour, Charlie Franks, Xhesi Galanxhi, Peter Marr, Alex Ryan and Jacob Walters.