Another major ransomware attack is currently spreading around the world.
According to Motherboard, "a wide range of private businesses" were affected on Tuesday, though it's unclear whether all the attacks are related.
Reuters Tech News posted on Twitter that pharmaceutical company Merck's computer network was compromised as part of a "global hack." In addition to Merck, the global law firm DLA Piper, U.K.-based advertising and public relations firm WPP, and an unnamed Ukranian media company may be among the victims of this outbreak, Motherboard reports.
Last month, hundreds of thousands of PCs were attacked by ransomware known as WannaCry, throwing government agencies and private businesses around the globe into disarray. WannaCry resurfaced just last week, infecting the network at a Honda factory in Japan and traffic cameras in Australia.
Now, security researchers say a strain of ransomware called Petya or Petrwrap, which has similarities to WannaCry, is spreading like wildfire, Motherboard reports. According to an image posted on Twitter (which you can see above), the malware encrypts the files on a user's system then demands victims pay $300 worth of bitcoin to recover access to their files.
"If you see this text, then your files are no longer accessible, because they have been encrypted," the message reads. "Perhaps you are busy looking for a way to recover your files, but don't waste your time. Nobody can recover your files without our decryption device."
The message goes on to "guarantee" victims will "safely and easily" recover all their files by submitting the payment.
Costin Raiu, a security researcher at Kaspersky Lab, likened the size of this attack to WannaCry's first hours. "We are seeing several thousands of infection attempts at the moment," he told Motherboard.
This story originally appeared on PCMag