The UK and South Korea have warned that cyber attacks from North Korean state-linked groups are growing in sophistication and volume.

In a new joint advisory issued by the two nations’ cyber security and intelligence agencies, they urge organisations to boost their security measures to reduce the risk of their systems being breached.

The UK’s National Cyber Security Centre (NCSC), which is part of GCHQ, and the South Korean National Intelligence Service (NIS) said they have observed hackers leveraging previously unknown vulnerabilities and exploits in third-party software in their supply chains in order to gain access to an organisation’s systems.

The two agencies have warned that such attacks on the software-based supply chain pose a particularly significant threat as it means a single initial compromise can affect a number of organisations and lead to onward attacks, resulting in greater disruption or ransomware being deployed.

In an increasingly digital and interconnected world, software supply chain attacks can have profound, far-reaching consequences for impacted organisations

The joint advisory warns that North Korean-backed attacks of this nature are likely to increase and urges organisations to take steps to better protect themselves.

Paul Chichester, NCSC director of operations, said: “In an increasingly digital and interconnected world, software supply chain attacks can have profound, far-reaching consequences for impacted organisations.

“Today, with our partners in the Republic of Korea, we have issued a warning about the growing threat from DPRK (North Korea) state-linked cyber actors carrying out such attacks with increasing sophistication.

“We strongly encourage organisations to follow the mitigative actions in the advisory to improve their resilience to supply chain attacks and reduce the risk of compromise.”

The joint advisory is the first time the NCSC has issued such a warning without partnership from other Five Eyes agencies – those in Australia, Canada, New Zealand and the US – and comes during the state visit to the UK by South Korean President Yoon Suk Yeol.