A new ransomware, or more likely, a new version of a well-known ransomware, is currently using an encryption algorithm even stronger than RSA-2048. The ransomware piece claims to have employed RSA-4096. Unfortunately, one of our own users has contacted us saying that he has found a ransomware message in all of his folders, claiming that files were encrypted via RSA-4096. You can read the message in the article body.
|Short Description||A new ransomware or a variant of a popular one has employed RSA-4096.|
|Symptoms||The encryption is most likely part of a malicious operation with a payload CryptoWall, TeslaCrypt, or another sophisticated rasomware.|
|Distribution Method||Via exploit kits, suspicious emails, etc.|
|Detection Tool||Download Malware Removal Tool, to See If Your System Has Been Affected by RSA-4096 Ransomware|
|User Experience||Join our forum to discuss RSA-4096 Encryption.|
As you will notice, the ransomware actors have embraced a more aggressive approach. Not only are they using stronger encryption that may take hundreds of years to decrypt, but they have become more hostile in their attitude towards victims. Appetite comes with eating, doesn’t it?
So, what is RSA-4096 encryption?
As we just said, this particular RSA encryption is much stronger than RSA-2048. According to security experts, the process of deciphering files encrypted by RSA-4096 will take many years, even if a super computer is used.
What led us to believe that a certain ransomware piece has employed this RSA algorithm? We received a complaint by one of our users, saying that they have found the following message, dropped in all of their folders:
NOT YOUR LANGUAGE? USE https://translate.google.com
What happened to your files ?
All of your files were protected by a strong encryption with RSA-4096.
More information about the encryption keys using RSA-4096 can be found here: http://en.wikipedia.org/wiki/RSA_(cryptosystem)
How did this happen ?
!!! Specially for your PC was generated personal RSA-4096 KEY, both public and private.
!!! ALL YOUR FILES were encrypted with the public key, which has been transferred to your computer via the Internet.
Decrypting of your files is only possible with the help of the private key and decrypt program, which is on our secret server.
What do I do ?
So, there are two ways you can choose: wait for a miracle and get your price doubled, or start obtaining BTC NOW, and restore your data easy way.
If You have really valuable data, you better not waste your time, because there is no other way to get your files, except make a payment.
For more specific instructions, please visit your personal home page, there are a few different addresses pointing to your page below:
[…] IMPORTANT INFORMATION:
Your personal pages:
http://[SYMBOLS](.)justmakeapayment.com/[…] http://[SYMBOLS](.)brsoftpayment.com/[…] http://[SYMBOLS].com/[…] https://[SYMBOLS].onion.to/[…] Your personal page (using TOR-Browser):
Your personal identification number (if you open the site (or TOR-Browser’s) directly): […] !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
This is what software engineer Daniel Pocock says about the RSA-4096 algorithm:
If an attack is found that allows a 2048 bit key to be hacked in 100 hours, that does not imply that a 4096 bit key can be hacked in 200 hours. The hack that breaks a 2048 bit key in 100 hours may still need many years to crack a single 4096 bit key. It is also worth noting that simply adding 1 bit (going from 1024 bits to 1025 bits) does not double the effort to crack the key, each extra bit adds some security but a little bit less than what was gained with the previous bit.
What should users affected by RSA-4096 encryption do?
As usual, the first step is to remove the threat that has dropped the ransomware onto your system. Our research indicates that one of the Trojans that may be dropping the ransomware is Trojan:Win32/Miuref:B, categorized as an infostealer.
Trojan:Win32/Miuref:B is most likely working together with the Nuclear exploit kit, applied in numerous ransomware and malware operations.
NB.The malicious process associated with the Trojan and the current RSA-4096 encryption probably goes like that:
→The user receives a suspicious email containing an infected link ->The user is redirected to a page that hosts the Nuclear EK (or some other exploit kit)-> Trojan:Win32/Miuref:B, or another infostealer, harvests information about the system-> If the system ‘meets’ the requirements (e.g. if the system is 64-bit, it won’t be attacked), the ransomware payload is dropped onto it.
We have reasons to suspect that two big ransomware families may have employed the RSA-4096 encryption algorithm. To no one’s surprise, they are:
Both of the ransomware families are quite active at the moment. Moreover, they have various variants and have made enough money out of ransoms to accomplish RSA-4096 encryption. Nonetheless, these are only assumptions. We will let you know when we gather enough information about the particular ransomware using RSA-4096.
For the moment, refer to the removal instructions below the article. As for decryption of files encrypted by RSA-4096 – if you haven’t backed up your data, we’re afraid nothing can be done (besides paying the ransom, which we never recommend, and hoping for obtaining your personal key).
UPDATE, Dec 15
The ransomware that is currently using RSA-4096 is most likely TeslaCrypt. The ransomware appends the well-known .vvv extension to the victim’s files, and we have already seen TeslaCrypt use this particular extension. More information is already available – see how to remove TeslaCrypt RSA-4096.