North Korea is behind an increasingly orchestrated effort at hacking into computers of financial institutions in South Korea and around the world to steal cash for the impoverished country, a South Korean state-backed agency said in a report.

In the past, suspected hacking attempts by North Korea appeared intended to cause social disruption or steal classified military or government data, but focus seems to have shifted in recent years to raising foreign currency, the South's Financial Security Institute (FSI) said.

The isolated regime is suspected to be behind a hacking group called Lazarus, which global cybersecurity firms have linked to last year's $81 billion cyberheist at the Bangladesh central bank as well as the 2014 attack on Sony's Hollywood studio.