An 11-year-old boy managed to hack into a replica of Florida’s election results website in 10 minutes and change names and tallies during a hackers convention, organizers said, stoking concerns about security ahead of nationwide votes.

The boy was the quickest of 35 children, ages 6 to 17, who all eventually got into copies of the websites of six swing states during the three-day Def Con security convention over the weekend.
The event was meant to test the strength of U.S. election infrastructure and shows all of the vulnerabilities that would be passed onto the states.

The hacking demonstration came as concerns mount about election system vulnerabilities before mid-term state and federal elections. President Donald Trump’s national security team sent a warning weeks ago that Russia had launched “pervasive” efforts to interfere in the November polls.

The convention linked to what it said was the Twitter account of the winning boy, named there as Emmett Brewer from Austin, Texas. A screenshot posted on the account showed he had managed to change the name of the winning candidate on the replica Florida website to his own and gave himself billions of votes.

The convention’s “Voting Village” also aimed to expose security issues in other systems such as digital poll books and memory-card readers.