The value of cryptocurrencies such as Bitcoin and Ethereum has risen dramatically over the last year, with Bitcoin increasing by 60% in 2021 and Ethereum increasing by 80%.

Thus, it's unsurprising that the relentless North Korean hackers who profit from the expanding crypto economy also had a banner year.

North Korea attempted at least seven attacks against cryptocurrency platforms last year, netting roughly $400 million in digital assets, according to a new research from blockchain monitoring firm Chainalysis.

According to the company's study, these attacks primarily targeted financial businesses and centralized exchanges.

The hackers employed a variety of techniques, including code exploits, phishing lures, malware, and clever social engineering, to steal money from platforms and deposit it in so-called hot wallets.

The nine-figure sum reflects an increase of roughly $100 million over the previous year's crimes by North Korean cyber organizations, bringing their five-year total to $1.5 billion in bitcoin alone, omitting the uncounted hundreds of millions more stolen from the traditional financial system.

According to Andy Greenberg of Wired, that cache of stolen bitcoin now adds significantly to Kim Jong Un's authoritarian regime's finances as it strives to fund itself - and its weapons projects - despite the country's heavily sanctioned, isolated, and failing economy.

"From 2020 to 2021, the number of North Korean-related hacks increased by 40%, from four to seven," Chainalysis reported Thursday.

North Korea initiated a meticulous laundering operation to conceal and cash out the proceeds, the study claimed.

As Chainalysis stated in its research, the reclusive state's latest internet escapades "create a vision of a country that promotes huge cryptocurrency-enabled criminality."

Last year, the Justice Department charged three North Korean people - Kim Il, Jon Chang Hyok, and Park Jin Hyok - with defrauding U.S. entities of $1.3 billion in cash and bitcoin.

As of January, the three hackers suspected of being responsible in the 2014 hack remain at large.

Additionally, a Canadian man was charged with assisting in the money laundering. However, those attempts have had no effect on the "hemorrhaging" of cryptocurrency riches.

"We were encouraged to see law enforcement agencies take action against North Korea," Erin Plante, Chainalysis' senior director of investigations, said. "Yet the threat continues to rise."

A United Nations panel of experts that monitors North Korea's sanctions has accused Pyongyang of evading restrictions by using stolen funds to bolster its nuclear and ballistic missile programs.