UBC wins fourth consecutive time at world-renowned “Capture the Flag" hacking competition

UBC Computer Science team makes history at hacking convention DEF CON 2025  

This August, UBC’s student hacking club, Maple Bacon, led by UBC Computer Science Professor Dr. Robert Xiao, won the “Capture the Flag” competition for the fourth time in a row at DEF CON, an annual hacking convention in Las Vegas. The winning team, Maple Mallard Magistrates, consists of three merged teams: Maple Bacon from UBC, Plaid Parliament of Pwning from Carnegie Mellon University (CMU), and The Duck from CMU’s alumni startup Theori.io. Only twelve teams qualified to compete in the Capture the Flag competition out of over 2000 teams this year. 

For three days straight, from August 7 - 10, 2025, hacking enthusiasts, ranging from students to researchers to cybersecurity professionals, worked in teams to break into each other's systems and extract “flags” while defending their own system by patching up vulnerabilities. The flags, which are bits of hidden texts, are then submitted for points. 

"These competitions require various skills, especially reverse engineering and binary exploitation,” says Aditya Adiraju, a UBC Computer Science and Mathematics student who participated in the competition. “We practiced in smaller competitions throughout the year to develop those skills.” 

The team started off strong, leading on the first day on Friday. But the second day left them on shaky grounds with the Live Capture-the-Flag event, in which each team chooses their best player to compete in a live, head-to-head battle. One of the teams used a custom-built AI model that was created specifically for the competition, outperforming every human and scoring their team huge points.  

It was unclear at the end of the second day who was going to be the winner. 

“We worked really hard throughout Saturday night,” says Dr. Xiao. “A lot of people didn’t sleep. We really had to try to lock down all of our exploits, patches and defenses.”  

But the setback didn’t stop the Maple Mallard Magistrates from going all in on the last day.  

“We basically had all guns firing,” says Dr. Xiao. “We didn’t know whether or not we could pull it off after the loss of the live Capture the Flag. We were able to pull out a victory, but it was close.” 

According to Aditya, the final moments of the competition were tense. “As we counted down, the whole room was just staring at the scoreboard.”  

Some of the UBC team members, including Lyndon Ho (Department of Computer Science), Sam Schweigel (Department of Electrical and Computer Engineering) and Aden Cross (Cognitive Systems), were awarded “Black Badges” for their substantial contributions to the competition. These awards are the highest honours given by the conference, granting the students free entry to DEF CON for life.  

“Our biggest strength as a team is that we are always striving to improve and we are dedicated to finding solutions,” says Aditya. “We’ve built a community that is inclusive to people’s growth.” 

While the competition is fun for the students, the educational aspect of these events can’t be understated. 

“Security is very cross-cutting, and we end up having to touch on topics like cryptography, computer programming languages, language design and so on,” says Dr. Xiao. “Students become much more well-rounded, holistic computer scientists through these competitions.” 

For Aditya, preparing for and participating in the Capture the Flag competitions has been an invaluable learning and networking experience. 

“It’s such a marvelous experience seeing our team members grow,” says Aditya. “I couldn’t be more proud of our team to represent UBC.”