WannaCry Decryption Kes
Although a decryption key became available recently for WannaCry victims, the success rate is minimal. WannaKey, is the free tool available to unlock files that were encrypted due to the global ransomware attack that hit on May 12, 2017. However, this decryption tool is only successful if the computer has not been rebooted after being infected and the associated memory has not been allocated and erased by some other process.
Although, there is still some hope. Another decryption key, WanaKiwi, has simplified the process that WannaKey provided. WanaKiwi is available here. WanaKiwi may not work for all encrypted files, but has been proved effective for Windows XP, Vista and 7 users.