How to remove KeRanger Ransomware and decrypt .encrypted files (Mac)

What is KeRanger Ransomware

Apple has already revoked the compromised certificate and updated XProtect antivirus signatures, and transmissionbt.com has removed malicious installers from its website and issued a warning to users.

Back in 2016, KeRanger became the very first ransomware that attacked Mac users. Most users were mind-blown when realized that their data is locked because they downloaded a legitimate BitTorrent Client called Transmission. At that time, cybercriminals managed to hack their website and ingrain a file-encrypting virus into a new version that was about to come out. Therefore, users inadvertently caught a malware attack by updating the previously installed application. The affected release was 2.90 after which, developers placed an urgent warning on their website that you should instantly upgrade to 2.92 which will ensure that KeRanger Ransomware is correctly removed from your computer. Of course, this damaged the reputation of Transmission significantly and appeared in a dramatic customer loss. Although KeRanger Ransomware splashed up a long time ago, it still can be downloaded via untrustworthy channels around the web.

KeRanger Ransomware (ransom note)

KeRanger Ransomware installer

How KeRanger Ransomware infected your Mac

Once the virus settles on the system, it drops an executable file disguised as General.rtf that initiates the process of encryption. KeRanger ciphers a wide range of files such as documents, images, videos, and others by appending a new .encrypted extension to each item. For example, standard 1.mp4 will be replaced by 1.mp4.encrypted and restrict access as a result. After encryption ransomware leaves a ransom note called README_FOR_DECRYPT.txt.

Unfortunately, laboratories have not identified the appropriate measure to decrypt the inflicted data. Instead, victims offer a paid solution which is buying a decryption program. The transaction has to be made via the Tor browser by paying 1 BTC (around 407 at that time), now Bitcoin accounts for roughly $5,260. Extortionists also claim that they will answer any of your questions if you are really motivated to pay a ransom. You can also decrypt 1 file via the Tor page linked in the note. As mentioned, third-parties tools are currently unable to decipher the locked data. But you can certainly delete KeRanger Ransomware from your Mac and remove quarantine folders/files. We will show how to do this below.

1. Download KeRanger Ransomware Removal Tool
2. Get decryption tool for .encrypted files
3. Recover encrypted files with Stellar Data Recovery Professional
4. Restore encrypted files with Windows Previous Versions
5. Restore files with Shadow Explorer
6. How to protect from threats like KeRanger Ransomware

KeRanger Ransomware files:


~/Desktop/README_FOR_DECRYPT.txt
~/Library/.kernel_complete
~/Library/.kernel_pid
~/Library/.kernel_time
~/Applications/Transmission.app/Contents/Resources/General.rtf
/Applications/Transmission.app/Contents/Resources/General.rtf
/Volumes/Transmission/Transmission.app/Contents/Resources/General.rtf
{randomfilename}


KeRanger Ransomware registry keys:

no information

How to decrypt and restore .encrypted files

Use automated decryptors

Download Trend Micro Ransomware Decryptor for macOS

Use following tool from Trend Micro called Ransomware Decryptor for macOS, that can decrypt .encrypted files. Download it here:

There is no purpose to pay the ransom because there is no guarantee you will receive the key, but you will put your bank credentials at risk.

Dr.Web Rescue Pack

Famous antivirus vendor Dr. Web provides free decryption service for the owners of its products: Dr.Web Security Space or Dr.Web Enterprise Security Suite. Other users can ask for help in the decryption of .encrypted files by uploading samples to Dr. Web Ransomware Decryption Service. Analyzing of files will be performed free of charge and if files are decryptable, all you need to do is purchase a 2-year license of Dr.Web Security Space worth $120 or less. Otherwise, you don’t have to pay.

If you are infected with KeRanger Ransomware and removed it from your computer you can try to decrypt your files. Antivirus vendors and individuals create free decryptors for some crypto-lockers. To attempt to decrypt them manually you can do the following:

Use Stellar Data Recovery Professional to restore .encrypted files

1. Download Stellar Data Recovery Professional for Mac.
2. Click Recover Data button.
3. Select type of files you want to restore and click Next button.
4. Choose location where you would like to restore files from and click Scan button.
5. Preview found files, choose ones you will restore and click Recover.

Using Time Machine:

If the Time Machine on your Mac is set up and running, do the following to restore your files.

1. Open Launchpad go to Other folder and choose Time Machine.
2. Scroll through the history of backups on the right until you find lost files.
3. Choose files you want to restore and click Restore button.

Using Terminal:

1. Open Applications > Utilities > Terminal.app.
2. In opened window type cd .Trash command and press Enter (Return).
3. Type mv {filename} ../ and press Enter. Please note, {filename} stands for the name of the file you want to restore.

If you are using Dropbox:

1. Login to the DropBox website and go to the folder that contains encrypted files.
2. Right-click on the encrypted file and select Previous Versions.
3. Select the version of the file you wish to restore and click on the Restore button.

How to protect computer from viruses, like KeRanger Ransomware, in future

1. Get special anti-ransomware software

Use RansomWhere? App

RansomWhere? is a small free utility for MacOS, that runs in the background and constantly monitors your system for the presence of processes that may encrypt your files. In case ransomware is detected, it shows you related alert and allows you to stop or block the malicious process immediately. RansomWhere?, if used properly, will save a major part of the data on your Mac. Download it below:

2. Back up your files

As an additional way to save your files, we recommend online backup. Local storages, such as hard drives, SSDs, flash drives, or remote network storages can be instantly infected by the virus once plugged in or connected to. KeRanger Ransomware uses some techniques to exploit this. One of the best services and programs for easy automatic online backup is iDrive. It has the most profitable terms and a simple interface. You can read more about iDrive cloud backup and storage here.

3. Do not open spam e-mails and protect your mailbox

Malicious attachments to spam or phishing e-mails are the most popular method of ransomware distribution. Using spam filters and creating anti-spam rules is good practice. One of the world leaders in anti-spam protection for Mac is SpamSieve. It works with Apple Mail and various third-party applications and provides a very high level of anti-spam protection. Download it here:

Summary

As statistics shows, Mac users are getting attacked by ransomware much more rarely in comparison to Windows. This is true evidence that Mac is well-protected from such infiltrations even without appendant anti-malware software. Although users downloaded KeRanger Ransomware unwillingly since it is a fault lying on Transmission developer’s shoulders, we still recommend being cautious of clicking on dubious ads and downloading unfamiliar software disguised under legitimate. This will ensure that your data is safe and not spied by third-parties remotely.