A nasty new form of ransomware is wreaking havoc on computers. Hackers that encrypt your files and demand money from you in the form of bitcoin is bad enough, but a few versions also overwrite your Windows PC's master boot record (MBR). The master boot record is a key part of your PC's startup system. It contains information about the computer's disk partitions and helps load the operating system. More recently, the Petya variant of ransomware has been causing MBR problems.

Attackers are developing an aggressive new ransomware program for Windows machines that encrypts user files as well as the computer's master boot record (MBR), leaving devices unable to load the OS. The program is dubbed Satana -- meaning "Satan" in Italian and Romanian -- and, according to researchers from security firm Malwarebytes, it is functional but still under development. Satana is the second ransomware threat affecting the MBR and seems inspired by another program, Petya, that appeared in March. The MBR code is stored in the first sectors of a hard disk drive, contains information about the disk's partitions and launches the operating system's boot loader. Without a proper MBR, computers don't know which partitions contain the OS and how to start it.

It's hard enough for non-technical users to deal with ransomware infections: understanding public-key cryptography, connecting to the Tor anonymity network and paying with Bitcoin cryptocurrency. A new malicious program now makes it even more difficult by completely locking victims out of their computers. The new Petya ransomware overwrites the master boot record (MBR) of the affected PCs, leaving their operating systems in an unbootable state, researchers from antivirus firm Trend Micro said in a blog post. The MBR is the code stored in the first sectors of a hard disk drive. It contains information about the disk's partitions and launches the operating system's boot loader.