BOSTON — Barnaby Jack, a celebrated computer hacker who could force a bank ATM to spit out cash and sparked safety improvements in medical devices, has died in San Francisco at age 35.

The San Francisco Medical Examiner’s Office said Jack died in Thursday. Officials gave no details.

Jack was due to appear at the Black Hat hacking convention in Las Vegas next week, demonstrating techniques for remotely attacking implanted heart devices.

His genius was finding bugs in the tiny computers embedded in such equipment as medical devices and bank machines.