- Jul 27, 2015
This new ransomware strain is a complex one, displaying a certain amount of innovation from the standard file-encryption approach of most others.
The affected device from which the ransomware infection originated was running Windows Server 2012 R2. By cleverly making use of a legitimate third-party disk encryption tool, the DeepBlueMagic ransomware started the encryption process not of files on the target’s endpoint, as ransomware usually does, but of the different disk drives on the server, except the system drive (the “C:\” partition). The legit disk encryption third-party tool used is “BestCrypt Volume Encryption” from Jetico. The “BestCrypt Volume Encryption” was still present on the accessible disk, C, alongside a file named “rescue.rsc”, a rescue file habitually used by Jetico’s software to recover the partition in case of damage. But unlike in the legitimate uses of the software, the rescue file itself was encrypted as well by Jetico’s product, using the same mechanism, and requiring a password in order to be able to open it.
It is a very unusual modus operandi for a ransomware strain, since these infections most often focus on files.
The DeepBlueMagic ransomware used Jetico’s product to start the encryption on all the drives except the system drive. The machine was found with the “C:\” drive intact, not encrypted in any way, and with ransom information text files on the desktop. The C drive is a smaller stakes ransomware target since the more valuable files are located on the other partitions, not on the system drive which is used for running executables and performing operations. In this case, it was the “D:\” drive that was turned into a RAW partition rather than the common NTFS, making it inaccessible. Any access attempt would have the Windows OS interface prompt the user to accept formatting the disk since the drive looks broken once encrypted.
Moreover, the ransomware cleared the stage before commencing the encryption. Before using Jetico’s “BestCrypt Volume Encryption”, the malicious software stopped every third-party Windows service found on the computer, to ensure the disabling of any security software which is based on behavior analysis. Leaving any such services active would have led to its immediate detection and blocking. Afterward, DeepBlueMagic deleted the Volume Shadow Copy of Windows to ensure restoration is not possible for the affected drives, and since it was on a Windows server OS, it tried to activate Bitlocker on all the endpoints in that active directory.
Our team of malware analysts has discovered a new strain of ransomware, DeepBlueMagic, with an innovative method of encrypting server partitions.