Last week, the WannaCry ransomware caused mayhem around the world, crippling vital serves such as those used by the NHS.

Now experts have warned that a new cyber threat called Adylkuzz is currently developing that could be even more devastating than the WannaCry attack.

Initial statistics suggest that the attack could affect hundreds of thousands of computers worldwide – although it is unclear which system will be targeted.

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Experts have warned that a new cyber threat called Adylkuzz is currently developing. Emerging reports suggest that this new attack could be even more devastating than the WannaCry attack – although it is unclear which computer system will be targeted (stock image)

WHAT IS ADYLKUZZ? Adylkuzz is a 'cryptocurrency miner' that infects computers, and generates cyber-money for the attackers. And while an individual computer may only generate a few pounds a week, the collective network can generate thousands of pounds for the hackers. Unlike ransomware, no demands for money are made of victims. Users will only notice their Windows machine is running slowly and that they don't have access to shared Windows resources. Advertisement

The new threat has been flagged by Proofpoint, a cybersecurity firm based in Sunnyvale, California.

In a post on its website, Proofpoint said: 'We discovered another very large-scale attack using both EternalBlue and DoublePulsar to install the cryptocurrency miner Adylkuzz.

'Initial statistics suggest that this attack may be larger in scale than WannaCry, affecting hundreds of thousands of PCs and servers worldwide.'

The Adylkuzz campaign started before the WannaCry ransomware attack hit on May 12, according to Proofpoint.

And the cybersecurity experts think that some firms may have mistakenly believed they were being victimised by the ransomware, when in fact it was Adylkuzz.

Adylkuzz is a 'cryptocurrency miner' that infects computers, and generates cyber-money for the attackers (stock image)

Adylkuzz is a 'cryptocurrency miner' that infects computers, and generates cyber-money for the attackers.

Proofpoint said: 'Symptoms of this attack include loss of access to shared Windows resources and degradation of PC and server performance.'

And while an individual computer may only generate a few pounds a week, the collective network can generate huge profits for the hackers.

Unlike ransomware (pictured), no demands for money are made of victims. Users will only notice their Windows machine is running slowly and that they don't have access to shared Windows resources

Robert Holmes, product vice president at Proofpoint, said: 'Unlike ransomware, no demands for money are made of victims.

'The malware is deliberately stealthy; users will only notice their Windows machine is running slowly and that they don't have access to shared Windows resources.'

Proofpoint added: 'This attack is ongoing and, while less flashy than WannaCry, is nonetheless quite large and potentially quite disruptive.'

It is unclear who is behind the Adylkuzz attack, or which computer system they plan to target.