The new attack targets the same vulnerabilities the WannaCry ransomware worm exploited but, rather than freeze files, uses the hundreds of thousands of computers believed to have been infected to mine virtual currency.

Following the detection of the WannaCry attack on Friday, "researchers at Proofpoint discovered a new attack linked to WannaCry called Adylkuzz," said Nicolas Godier, a researcher at the computer security firm.

This other very large-scale attack uses 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: because this attack shuts down SMB networking to prevent further infections with other malware (including the WannaCry worm) via that same vulnerability, it may have in fact limited the spread of last week's WannaCry infection.