Bitcoin prices have been at an all-time high but the cryptocurrency could be facing growing risks of hacking due to its unexpected value increase.
Mr McNamara said: “The fact that it has appreciated so much in value this year means that it’s attracting a lot of interest from various cybercriminals.
“We have noticed North Korean hackers actually pivot to start going after places like cryptocurrency exchanges in South Korea.”
The cybersecurity expert said his company had noticed hackers previously linked to espionage activities for the North Korean government take a sudden interest in bitcoin early in the year.
He suggested hacking bitcoin had become a way to “bring in” money as sanctions against Pyongyang increased due to its aggressive rhetoric against the international community.
Speaking to CNN, Mr McNamara said: “It’s a way to help bring in cash as sanctions have really ratcheted up this year.”
North Korea has been implicated in a possible bitcoin hack that led to the bankruptcy of South Korean currency exchange Youbit.
It has also been reported that North Korean hackers targeted the same cryptocurrency exchange when it was operating under a different name in April.
Officials in Seoul say they are keeping tabs on North Korea’s bitcoin-related activities, which analysts warn are being used to subvert international sanctions.
Mr McNamara said South Korea had addressed the problem with bitcoin hacking with a new set of security proposals and regulations.
He said: “The South Korean Government came out and instituted some new proposals and regulations. Some of which are going to increase the security that these cryptocurrencies need to operate under.”
But despite a recent buying-rush, bitcoin prices went down since digital currency exchange Coinbase launched an investigation over fears its staff exploited the firm’s move into the bitcoin cryptocurrency.
Bitcoin was down to $16895 (£12642) this morning after climbing above $19600 late last week.
The cryptocurrency is continuing to drop and it is currently valued at £12140, according to Coindesk on Thursday afternoon.