North Korean group APT43 has used crypto services to launder stolen currency, according to a new report from threat intelligence firm Mandiant.

This is part of the group's wider mission of cyber espionage of other countries, with the U.S. and South Korea being two of the main targets, the report said.

"In contrast to other North Korean groups such as APT38, which are likely primarily tasked to bring in funds for the regime, APT43 most likely carries out such operations to sustain its own operations," it said.

APT43 likely used stolen bitcoin to pay for hash rental and cloud mining services which on the other end would result in "clean bitcoin," Mandiant said.

"For a fee, these hash rental and cloud mining services provide hash power, which is used to mine cryptocurrency to a wallet selected by the buyer without any blockchain-based association to the buyer’s original payments," the firm also said.

Cloud mining services offer anyone the chance to mine bitcoin by simply paying a fee instead of having to install and run mining machines themselves, which are instead in a shared remote location.