A new ransomware called Apocalypse was discovered by Emsisoft that encrypts your data and then requires you to email email@example.com for ransom instructions. Thankfully, Fabian Wosar of Emsisoft was able to create a decryptor for this ransomware.
When files are encrypted they will have the .encrypted extension appended to file names. Furthermore, for each file encrypted a ransom note will be created. For example, if Apocalypse encrypts a file called test.jpg, a test.jpg.encrypted file and a test.jpg.encrypted.How_To_Decrypt.txt file will be created.
The ransomware will also create an autorun entry that points to C:\Program Files (x86)\windowsupdate.exe so that the ransomware is started when a user logs into Windows. Once started, it will display a lock screen like the one below. You can reboot into safe mode to bypass the lock screen and run the decryptor.