Mobef Ransomware Encrypts With .KEYZ Extension and Uses DES and AES Ciphers

by Ventsislav Krastev | May 4, 2016 | 0 Comments Crypto-Malware, file-encryption, ransomware, Windows

Ransomware that uses different encryption techniques, named Mobef has been reported to ask ransom money to give infected users access to the files it encrypts on their computers. Unlike other ransomware infections, Mobef may employ the DES encryption algorithm, suggesting that the malware writers behind it wanted to create a virus that is different and less familiar to researchers and users. However, users should know that unlike AES, the DES algorithm is weaker against brute forcing attacks and file decryption may be possible.

Threat Summary

Name	Mobef
Type	Ransomware
Short Description	The ransomware encrypts files with the RSA algorithm and AES-128 ciphers and asks a ransom for decryption.
Symptoms	Files are encrypted and become inaccessible. A ransom note with instructions for paying the ransom shows as a .txt file.
Distribution Method	Spam Emails, Email Attachments, File Sharing Networks.
Detection Tool	See If Your System Has Been Affected by malware Download Malware Removal Tool
User Experience	Join our forum to Discuss Mobef Ransomware.
Data Recovery Tool	Windows Data Recovery by Stellar Phoenix Notice! This product scans your drive sectors to recover lost files and it may not recover 100% of the encrypted files, but only few of them, depending on the situation and whether or not you have reformatted your drive.

Mobef Ransomware – Distribution

To spread across the web, Mobef is believed to utilize an exploit kit which is quite dangerous. Examples of different exploit kit attacks you may see by visiting the following article. This is why users with non regularly patched software and without experience in browsing and using e-mails safely may be the most likely victims. This may happen via a drive by download when the user has clicked on a malicious web link, such as the one on an example spam e-mail below:

Mobef Ransomware – The Threat In Detail

Once the ransomware has been executed on your computer, it may have the following executables:

33.tmp.exe
Ransom.Mobef.A.exe
Tmp.exe

Those files may be the executables which encrypt the user data, and this very ransomware may create custom registry entries for them in the following Windows Registry Key:

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run\

After doing so, upon system boot, Mobef ransomware may begin to encrypt files that are most widely and commonly used. The encrypted data is with a strong AES and a bit outdated DES encryption algorithms. The ransomware is reported by Symantec Researchers to scan for and encrypt files with the following file extensions:

→ .3ds .4db .4dd .7z .7zip .accdb .accdt .aep .aes .ai .alk .arj .axx .bak .bpw .cdr .cer .crp .crt .csv .db .dbf .dbx .der .doc .docm .docx .dot .dotm .dotx .drc .dwfx .dwg .dwk .dxf .eml .enz .fdb .flk .flka .flkb .flkw .flwa .gdb .gho .gpg .gxk .hid .hid2 .idx .ifx .iso .k2p .kdb .kdbx .key .ksd .max .mdb .mdf .mpd .mpp .myo .nba .nbf .nsf .nv2 .odb .odp .ods .odt .ofx .ost .p12 .pdb .pdf .pfx .pgp .ppj .pps .ppsx .ppt .pptx .prproj .psd .pst .psw .qba .qbb .qbo .qbw .qfx .qif .rar .raw .rfp .rpt .rsa .rtf .saj .sdc .sdf .sef .sko .sql .sqlite .sxc .tar .tax .tbl .tc .tib .txt .wdb .xbrl .xls .xlsm .xlsx .xml .zip

Furthermore, Mobef uses a text file to notify the user and may drop it on the user’s desktop. The text file name contains the date of the infection after which the ”-INFECTION” part is added to the name of the file. It contains the following ransom instructions:

→ “YourID: {CUSTOM NUMERICAL USER ID}
PC: {PC NAME}
USER: {USERNAME}
Hey
Your files are now encrypted. I have the key to decrypt them back. I will give you a decrypter if you pay me. Email me at: momsbestfriend@protonmail.com or torrenttracker@india.com
If you don’t get a reply or if both emails die, then contact me using a guaranteed, foolproof
Bitmessage: download it form here https://github.com/mailchuck/PyBitmessage/releases/download/v0.5.8/Bitmessage-
0.5.8.exe
Run it, click New Identity and then send me a message at {BITMESSAGE BITCOIN ADDRESS}
Cheers”Source:Bleeping Computer

Not only this, but the ransomware may change the wallpaper of the infected user with the very same ransom message:

Users who have had their files encrypted report seeing two types of files in the folders where their files were encrypted:

The ransom note text file.
A .key file which most likely contains either the public or the private key for the files.

Remove Mobef Ransomware and Restore the Encrypted Files

The removal of Mobef may be rather simple if done via an anti-malware software which will automatically discover the malicious files and remove them. There is also the manual option of finding the malicious .tmp, .exe and other files and deleting them permanently. But then again, you should also make sure to clean up your registry entries.

The decryption of files encoded with DES and AES algorithms is almost impossible, not before a flaw in the code is found. This is why we advise you to follow the step-by-step restoration instructions below that contain alternative methods which go around the direct decryption. In the meantime, you can follow our security forum or updates on our blog in case a free decryption method surfaces.

Ventsislav Krastev

Ventsislav is a cybersecurity expert at SensorsTechForum since 2015. He has been researching, covering, helping victims with the latest malware infections plus testing and reviewing software and the newest tech developments. Having graduated Marketing as well, Ventsislav also has passion for learning new shifts and innovations in cybersecurity that become game changers. After studying Value Chain Management, Network Administration and Computer Administration of System Applications, he found his true calling within the cybersecrurity industry and is a strong believer in the education of every user towards online safety and security.

How to Remove Mobef from Windows.

Step 1: Boot Your PC In Safe Mode to isolate and remove Mobef

OFFER

Manual Removal Usually Takes Time and You Risk Damaging Your Files If Not Careful!

We Recommend To Scan Your PC with SpyHunter

Keep in mind, that SpyHunter’s scanner is only for malware detection. If SpyHunter detects malware on your PC, you will need to purchase SpyHunter's malware removal tool to remove the malware threats. Read our SpyHunter 5 review. Click on the corresponding links to check SpyHunter's EULA, Privacy Policy and Threat Assessment Criteria

1. Hold Windows key() + R

2. The "Run" Window will appear. In it, type "msconfig" and click OK.

3. Go to the "Boot" tab. There select "Safe Boot" and then click "Apply" and "OK".

Tip: Make sure to reverse those changes by unticking Safe Boot after that, because your system will always boot in Safe Boot from now on.

4. When prompted, click on "Restart" to go into Safe Mode.

5. You can recognise Safe Mode by the words written on the corners of your screen.

Step 2: Uninstall Mobef and related software from Windows

Here is a method in few easy steps that should be able to uninstall most programs. No matter if you are using Windows 10, 8, 7, Vista or XP, those steps will get the job done. Dragging the program or its folder to the recycle bin can be a very bad decision. If you do that, bits and pieces of the program are left behind, and that can lead to unstable work of your PC, errors with the file type associations and other unpleasant activities. The proper way to get a program off your computer is to Uninstall it. To do that:

1. Hold the Windows Logo Button and "R" on your keyboard. A Pop-up window will appear.

2. In the field type in "appwiz.cpl" and press ENTER.

3. This will open a window with all the programs installed on the PC. Select the program that you want to remove, and press "Uninstall"

Follow the instructions above and you will successfully uninstall most programs.

Step 3: Clean any registries, created by Mobef on your computer.

The usually targeted registries of Windows machines are the following:

HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\RunOnce
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\RunOnce

You can access them by opening the Windows registry editor and deleting any values, created by Mobef there. This can happen by following the steps underneath:

1. Open the Run Window again, type "regedit" and click OK.

2. When you open it, you can freely navigate to the Run and RunOnce keys, whose locations are shown above.

3. You can remove the value of the virus by right-clicking on it and removing it.

Tip: To find a virus-created value, you can right-click on it and click "Modify" to see which file it is set to run. If this is the virus file location, remove the value.

IMPORTANT!
Before starting "Step 4", please boot back into Normal mode, in case you are currently in Safe Mode.
This will enable you to install and use SpyHunter 5 successfully.

Step 4: Scan for Mobef with SpyHunter Anti-Malware Tool

1. Click on the "Download" button to proceed to SpyHunter's download page.

Download

Malware Removal Tool

It is recommended to run a scan before purchasing the full version of the software to make sure that the current version of the malware can be detected by SpyHunter. Click on the corresponding links to check SpyHunter's EULA, Privacy Policy and Threat Assessment Criteria.

2. After you have installed SpyHunter, wait for it to update automatically.

3. After the update process has finished, click on the 'Malware/PC Scan' tab. A new window will appear. Click on 'Start Scan'.

4. After SpyHunter has finished scanning your PC for any files of the associated threat and found them, you can try to get them removed automatically and permanently by clicking on the 'Next' button.

If any threats have been removed, it is highly recommended to restart your PC.

Step 5 (Optional): Try to Restore Files Encrypted by Mobef.

Ransomware infections and Mobef aim to encrypt your files using an encryption algorithm which may be very difficult to decrypt. This is why we have suggested a data recovery method that may help you go around direct decryption and try to restore your files. Bear in mind that this method may not be 100% effective but may also help you a little or a lot in different situations.

1. Download the reccomended Data Recovery software by clicking on the link underneath:

EaseUS Data Recovery Software

Simply click on the link and on the website menus on top, choose Data Recovery - Data Recovery Wizard for Windows or Mac (depending on your OS), and then download and run the tool.

Windows Mac OS X

Get rid of Mobef from Mac OS X.

Step 1: Uninstall Mobef and remove related files and objects

OFFER

Manual Removal Usually Takes Time and You Risk Damaging Your Files If Not Careful!

We Recommend To Scan Your Mac with SpyHunter for Mac

Keep in mind, that SpyHunter for Mac needs to purchased to remove the malware threats. Click on the corresponding links to check SpyHunter’s EULA and Privacy Policy

1. Hit the ⇧+⌘+U keys to open Utilities. Another way is to click on “Go” and then click “Utilities”, like the image below shows:

2. Find Activity Monitor and double-click it:

3. In the Activity Monitor look for any suspicious processes, belonging or related to Mobef:

Tip: To quit a process completely, choose the “Force Quit” option.

4. Click on the "Go" button again, but this time select Applications. Another way is with the ⇧+⌘+A buttons.

5. In the Applications menu, look for any suspicious app or an app with a name, similar or identical to Mobef. If you find it, right-click on the app and select “Move to Trash”.

6: Select Accounts, after which click on the Login Items preference. Your Mac will then show you a list of items that start automatically when you log in. Look for any suspicious apps identical or similar to Mobef. Check the app you want to stop from running automatically and then select on the Minus (“-“) icon to hide it.

7: Remove any left-over files that might be related to this threat manually by following the sub-steps below:

Go to Finder.
In the search bar type the name of the app that you want to remove.
Above the search bar change the two drop down menus to “System Files” and “Are Included” so that you can see all of the files associated with the application you want to remove. Bear in mind that some of the files may not be related to the app so be very careful which files you delete.
If all of the files are related, hold the ⌘+A buttons to select them and then drive them to “Trash”.

In case you cannot remove Mobef via Step 1 above:

In case you cannot find the virus files and objects in your Applications or other places we have shown above, you can manually look for them in the Libraries of your Mac. But before doing this, please read the disclaimer below:

Disclaimer! If you are about to tamper with Library files on Mac, be sure to know the name of the virus file, because if you delete the wrong file, it may cause irreversible damage to your MacOS. Continue on your own responsibility!

1: Click on "Go" and Then "Go to Folder" as shown underneath:

2: Type in "/Library/LauchAgents/" and click Ok:

3: Delete all of the virus files that have similar or the same name as Mobef. If you believe there is no such file, do not delete anything.

You can repeat the same procedure with the following other Library directories:

→ ~/Library/LaunchAgents
/Library/LaunchDaemons

Tip: ~ is there on purpose, because it leads to more LaunchAgents.

Click the button below below to download SpyHunter for Mac and scan for Mobef:

Download

SpyHunter for Mac

Step 3 (Optional): Try to Restore Files Encrypted by Mobef.

1. Download the reccomended Data Recovery software by clicking on the link underneath:

EaseUS Data Recovery Software

Simply click on the link and on the website menus on top, choose Data Recovery - Data Recovery Wizard for Windows or Mac (depending on your OS), and then download and run the tool.

Mobef FAQ

What is Mobef ransomware and how does it work?

Mobef is a ransomware infection - the malicious software that enters your computer silently and blocks either access to the computer itself or encrypt your files.

Many ransomware viruses use sophisticated encryption algorithm how to make your files inaccessible. The goal of ransomware infections is to demand that you pay a ransom payment to get access to your files back.

How does Mobef ransomware infect my computer?

Via several ways.Mobef Ransomware infects computers by being sent via phishing e-mails, containing virus attachment.

This attachment is usually masked as an important document, like an invoice, bank document or even a plane ticket and it looks very convincing to users.

After you download and execute this attachment, a drive-by download occurs and your computer is infected with the ransomware virus.

Another way, you may become a victim of Mobef is if you download a fake installer, crack or patch from a low reputation website or if you click on a virus link. Many users report getting a ransomware infection by downloading torrents.

How to open .Mobef files?

You can't. At this point the .Mobef files are encrypted. You can only open them once they are decrypted.

Decryptor did not decrypt my data. What now?

Do not panic and backup the files. If a decryptor did not decrypt your .Mobef files successfully, then do not despair, because this virus is still new.

One way to restore files, encrypted by Mobef ransomware is to use a decryptor for it. But since it's a new virus, advised that the decryption keys for it may not be out yet and available to the public. We will update this article and keep you posted as soon as this decryptor is released.

How Do I restore ".Mobef" files (Other Methods)?

Yes, sometimes files can be restored. We have suggested several file recovery methods that could work if you want to restore .Mobef files.

These methods are in no way 100% guarantee that you will be able to get your files back. But if you have a backup, your chances of success are much greater.

How do I get rid of Mobef ransomware virus?

The safest way and the most efficient one for the removal of this ransomware infection is the use a professional anti malware software. It will scan for and locate Mobef ransomware and then remove it without causing any additional harm to your important .Mobef files.

Also, keep in mind that viruses like Mobef ransomware also install Trojans and keyloggers that can steal your passwords and accounts. Scanning your computer with an anti-malware software will make sure that all of these virus components are removed and your computer is protected in the future.

What to Do If nothing works?

There is still a lot you can do. If none of the above methods seem to work for you, then try these methods:

Try to find a safe computer from where you can can login on your own line accounts like One Drive, iDrive, Google Drive and so on.
Try to contact your friends, relatives and other people so that they can check if they have some of your important photos or documents just in case you sent them.
Also, check if some of the files that were encrypted it can be re-downloaded from the web.
Another clever way to get back some of your files is to find another old computer, a flash drive or even a CD or a DVD where you may have saved your older documents. You might be surprised what will turn up.
You can also go to your email account to check if you can send any attachments to other people. Usually what is sent the email is saved on your account and you can re-download it. But most importantly, make sure that this is done from a safe computer and make sure to remove the virus first.

More tips you can find on our forums, where you can also asks any questions about your ransomware problem.