Are you affected by WannaCry!. French researchers have found a way to decrypt Windows computers infected with WannaCry without having to pay the cyber criminals.

Their tools, wannakey and wanakiwi, are able to recover the key used to encrypt the files if it is still in the computer’s memory. It can then be used to restore the encrypted files on infected computers.

But the security researchers warned that the tools would only work if the computer had not been rebooted. Wannakey works for Windows XP and, as Adrien Guinet, a security expert and developer of the tool, said: “You need some luck for this to work and so it might not work in every case.”

Wanakiwi, developed by Benjamin Delpy – who worked on it during in his spare time outside his day job at the Banque de France – has been shown to work on Windows XP and Windows 7, as well as Windows server 2003, and will probably work on Windows Vista and other variants of Windows affected by WannaCry,