Gryphon ransomware virus - How to remove

Gryphon ransomware virus has been nailed down to be a newer version of BTCWare infection and not Amnesia (this was the first assumption that security researchers had mistakenly made). Despite belonging to the BTCWare (1) family of infections that include such samples like Master virus, we have to observe couple of distinguishing factors that individuate Gryphon from the preceding variants.

Update of the Gryphon computer virus

Gryphon ransomware virus (2) demands that its victims would contact the authors of this computer disease via specific email addresses: [email protected] or [email protected]. Also, next to the extensions that we enumerate below, this BTCWare variant also appends .[[email protected]].crypton. Also, to clarify one thing: this sample takes advantage of both RSA-1024 cipher and AES. As it has become expected of crypto-infection, the AES will be assigned to encrypt digital files. After this process, the RSA will corrupt the private key for decryption that was designed during the process of encoding.

According to technical analysis of this variant (3), HVVBJHDGTRYS.exe has been indicated to be the payload. In this detected sample, a new extension was exploited to mark the ruined executables: .[[email protected]].gryphon. This Gryphon sample was indicated to be a Trojan.GenericKD.12124860, TR/Crypt.XPACK.Gen7, Trojan-Ransom.Win32.Cryptor.jg. Also, according to this recent twitter post (4), unpacked Gryphon crypto-virus was distributed via malspam strategy, specializing in Blank Slate. Also, we detected another payload (5) to be distributed with the hopes of delivering this ransomware: 1.dat.

Investigation of this crypto-virus

While unprotected remote desktop protocols (RDPs) were the vulnerability that hackers exploited with their older projects, their newest crypto-virus has been determined to exploit spam letters for its distribution. However, a heated discussion has recently began and it suggest that a strategy of BlankSlate/malspam is the exact technique for transmission. This means that empty email letters, containing only .zip attachments, are being sent around to potential victims.

Another feature that makes Gryphon differ from BTCWare is a different RSA cipher being exploited; it also encodes 64k. Digital data which has been touched by cryptography will contain a specific extension of [[email protected]].gryphon extension or the .[[email protected]].gryphon.

Currently, email addresses of [email protected], [email protected], [email protected] and [email protected] have been blamed for spreading malicious payloads in form of archive files. The distributed files will look something like this: EMAIL_7229655_[recipient].zip. Yes, targeted victims’ email addresses are incorporated into the filename for that extra touch of credibility.

The distributed email letters do not have any text content or titles. If a person, for some reason, downloads these files and extracts them, an additional .zip archive will be required to be handled. Then, .js files are presumably going to be launched and they will be responsible for setting up the ransomware infection.

Soon after the actions in the paragraph above are done, ransomware will be permitted to move full speed ahead. It will cipher files and place HELP.txt file as the ransom note. In this message, people will be informed that their data has been damaged and users should contact [email protected] if they wish to discuss file-decryption. To prove their credibility, hackers are offering to decipher 3 executables. If crooks are idle to respond and victim has not received a reply for 2 days, [email protected] is indicated to be a helpful alternative.

Methods that could help you decrypt data

A decrypter for this infection has not been published yet. However, we do hope that such a glorious news will be announced. We are sure that security researchers are working on such a software, but it depends whether the tool will be generated. If you wish to help out, provide hackers with three of your encrypted data. Maybe if security researchers would receive encrypted and decrypted versions, it would help them.

However, contacting hackers for the reason of paying a ransom is not wise. This sum is not included in the .txt file but it will be revealed if victims contact hackers via the earlier-mentioned email addresses. It does not matter what sum they are demanding: abiding by the rules of crooks and purchasing bitcoins will only support future ransomware projects.

If we ever wish to escape ransomware infections, we have to become protected. The easiest way to secure your digital data is to have it available in more than one location. For instance, you could have the original versions in your hard drive, and copies in a backup storage or an USB flash drive. If every Internet surfer would follow this advise, creators of ransomware would lose their jobs since there would be no possibilities for profit.

In the sections below, we explain how encrypted data could be restored. However, before you try these techniques, it is crucial for you to remove all sources of malicious activity. Examine your operating system with Spyhunter and this tool will have no issue in helping you get rid of all malware samples.

How to recover Gryphon ransomware virus encrypted files and remove the virus

Step 1. Restore system into last known good state using system restore

1. Reboot your computer to Safe Mode with Command Prompt:

for Windows 7 / Vista/ XP

• Start → Shutdown → Restart → OK.
• Press F8 key repeatedly until Advanced Boot Options window appears.
• Choose Safe Mode with Command Prompt.

for Windows 8 / 10

• Press Power at Windows login screen. Then press and hold Shift key and click Restart.
• Choose Troubleshoot → Advanced Options → Startup Settings and click Restart.
• When it loads, select Enable Safe Mode with Command Prompt from the list of Startup Settings.

 

2.Restore System files and settings.

• When Command Prompt mode loads, enter cd restore and press Enter.
• Then enter rstrui.exe and press Enter again.
• Click “Next” in the windows that appeared.
• Select one of the Restore Points that are available before Gryphon ransomware virus has infiltrated to your system and then click “Next”.
• To start System restore click “Yes”.

 

Step 2. Complete removal of Gryphon ransomware virus

After restoring your system, it is recommended to scan your computer with an anti-malware program, like Spyhunter and remove all malicious files related to Gryphon ransomware virus . You can check other tools here.  

Step 3. Restore Gryphon ransomware virus affected files using Shadow Volume Copies

If you do not use System Restore option on your operating system, there is a chance to use shadow copy snapshots. They store copies of your files that point of time when the system restore snapshot was created. Usually Gryphon ransomware virus tries to delete all possible Shadow Volume Copies, so this methods may not work on all computers. However, it may fail to do so. Shadow Volume Copies are only available with Windows XP Service Pack 2, Windows Vista, Windows 7, and Windows 8. There are two ways to retrieve your files via Shadow Volume Copy. You can do it using native Windows Previous Versions or via Shadow Explorer. a) Native Windows Previous Versions Right-click on an encrypted file and select Properties → Previous versions tab. Now you will see all available copies of that particular file and the time when it was stored in a Shadow Volume Copy. Choose the version of the file you want to retrieve and click Copy if you want to save it to some directory of your own, or Restore if you want to replace existing, encrypted file. If you want to see the content of file first, just click Open.

b) Shadow Explorer It is a program that can be found online for free. You can download either a full or a portable version of Shadow Explorer. Open the program. On the left top corner select the drive where the file you are looking for is a stored. You will see all folders on that drive. To retrieve a whole folder, right-click on it and select “Export”. Then choose where you want it to be stored.

Step 4. Use Data Recovery programs to recover Gryphon ransomware virus encrypted files

There are several data recovery programs that might recover encrypted files as well. This does not work in all cases but you can try this:

• We suggest using another PC and connect the infected hard drive as slave. It is still possible to do this on infected PC though.
• Download a data recovery program.
• Install and scan for recently deleted files.

Note: In many cases it is impossible to restore data files affected by modern ransomware. Thus I recommend using decent cloud backup software as precaution. We recommend checking out Carbonite, BackBlaze, CrashPlan or Mozy Home.

References:

1. Bitcoin Ransomware Education – BTCWare. Themerkle.com.
2. Ransomware: 5 dos and dont’s. Us.norton.com.
3. Analysis. Virustotal.com.
4. Unpacked Gryphon ransomware. Twitter.com.
5. Analysis. Virustotal.com.