The three bitcoin wallets tied to the WannaCry ransomware attacks, which contained over $140,000 (£106, 400) worth of bitcoins paid by the victims of the ransomware attack, have now been emptied out by hackers. Since the attack hit organisations across the globe in May, the bitcoin wallets have seen numerous payments but no withdrawals, until now.

However, on Wednesday (2 August) night, the hackers in control of the bitcoin wallets began making rapid withdrawals. According to the Twitter account tracking the WannaCry ransom wallets, the hackers cached out $70,000 in three successive withdrawals and 5 minutes later proceeded to withdraw another $70,000. Ten minutes later, the hackers made a final withdrawal of a little over $26,000, emptying all three bitcoin accounts tied to the ransomware attacks.

It is still unclear as to who emptied out the accounts. However, security experts as well as law enforcement authorities, including the GCHQ have previously linked the WannaCry attacks to North Korean hackers. According to the NSA, the ransomware epidemic may have been the work of North Korean hackers, believed to be linked to Pyongyang's spy agency - the Reconnaissance General Bureau (RGB).

According to the NSA, the attacks may have been the hackers' attempt at generating money for North Korea, which has been facing numerous international sanctions over its nuclear program.

A South Korean think tank recently reported that North Korean hackers' motives in conducting attacks has recently shifted from cyberespionage to generating money for the impoverished dictatorial regime.

Meanwhile, according to Matthieu Suiche, founder of Comae Technologie, law enforcement agencies will now be on the alert, tracking the recently withdrawn bitcoins, in efforts to hunt the cybercriminals responsible for the WannaCry attacks, CNN reported.

Melanie Shapiro, CEO of identity security firm Token said that the hackers may have moved the money to make them untraceable, thereby covering their tracks. "We can watch all of this bitcoin be moved around, but inevitably every move makes it harder to trace back to an individual," she said.