Petya is a piece of malicious computer code classified as ransomware. The software was first detected in the Ukraine, and quickly spread to at least 26 other countries a day later.[1] It is mostly spread by fake e-mail message, such as a job application. Once the file is downloaded (which typically looks like a curriculum vitae document) it infects the mater boot record, and crashed the computer to a "blue screen of death". When the user restarts the computer, the malware is executed, but makes it appear as though a regular check-disk is being performed. During this time, it encrypts the master file table. Once complete, it reveals itself and demands a ransom from the user to recover access to their files. Technically, their files have not been encrypted, but without the master file table it is very difficult to locate the files on a drive. Advanced recovery software and techniques can sometimes be used to recover these files, but it is difficult to do by ones self, and if done by a hired professional is fairly expensive.[2][3]