A programmer accidentally created a bug that left the door open for hackers to take over a computer remotely.
Ilya Kolmanovskiy, a 23-year-old graduate of the University of California, Berkeley, discovered the bug in Oracle's Java software and reported it to the company.
The next day he received an automated response from Oracle telling him it was working on the problem and would get back to him in around two weeks.
A few days later he discovered that hackers had already begun exploiting the bug before Oracle had fixed it. "I was scared," he told the BBC. "It took them a month to write this exploit code.