New Satana ransomware encrypts user files and master boot record

It's the second ransomware threat after Petya that leaves computers unable to boot into the OS

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.

There are significant differences between Satana and Petya. For example, Petya replaces the MBR in order to launch a custom bootloader that then encrypts the system's master file table (MFT) -- a special file on NTFS partitions that contains information about all other files, like names, sizes and mappings to the hard disk sectors.

Satana doesn't encrypt the MFT. It just replaces the MBR with its own code and stores an encrypted version of the original boot record so it can restore it later if the victim pays the ransom. This leaves the computer unbootable, but can be fixed more easily than if the MFT had also been encrypted.

In May, Petya was combined with a separate ransomware program, called Mischa, which exhibits a more traditional behavior: it encrypts users' personal files directly if it can't obtain administrator privileges to attack the MBR and MFT.

Satana uses the same combination of traditional file encryption and MBR encryption, but in the same program. It first encrypts user files with specific extensions and then waits patiently for the first reboot, at which time it replaces the MBR. The user then sees a screen demanding a ransom payment of 0.5 bitcoin (about US$340).

This routine makes it harder for nontechnical users to restore their systems, because it forces them to use a separate computer to make the payment, as the affected computer can no longer boot into Windows.

"Unfortunately, at this time there is no way to decrypt Satana encrypted files for free," said Lawrence Abrams, founder of the BleepingComputer.com tech support forum, in a blog post.

Users might be able to repair the MBR by using the Windows recovery options, but this requires working with the Windows command line and the bootrec.exe (boot recovery) tool, so it is likely beyond the abilities of typical users.

The current version of Satana hasn’t yet been widely distributed, and the researchers don’t expect that it will because the code is not yet mature and has flaws. However, they believe this version will likely serve as a base for future improvements.

Join the newsletter!

Or

Sign up to gain exclusive access to email subscriptions, event invitations, competitions, giveaways, and much more.

Membership is free, and your security and privacy remain protected. View our privacy policy before signing up.

Error: Please check your email address.
Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.
Lucian Constantin

Lucian Constantin

IDG News Service
Show Comments

Most Popular Reviews

Latest Articles

Resources

PCW Evaluation Team

Tom Pope

Dynabook Portégé X30L-G

Ultimately this laptop has achieved everything I would hope for in a laptop for work, while fitting that into a form factor and weight that is remarkable.

Tom Sellers

MSI P65

This smart laptop was enjoyable to use and great to work on – creating content was super simple.

Lolita Wang

MSI GT76

It really doesn’t get more “gaming laptop” than this.

Jack Jeffries

MSI GS75

As the Maserati or BMW of laptops, it would fit perfectly in the hands of a professional needing firepower under the hood, sophistication and class on the surface, and gaming prowess (sports mode if you will) in between.

Taylor Carr

MSI PS63

The MSI PS63 is an amazing laptop and I would definitely consider buying one in the future.

Christopher Low

Brother RJ-4230B

This small mobile printer is exactly what I need for invoicing and other jobs such as sending fellow tradesman details or step-by-step instructions that I can easily print off from my phone or the Web.

Featured Content

Product Launch Showcase

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?