A new variant of the Jaff ransomware is out that appends the .wlu extension to enciphered files, presents itself as Jaff Decryptor and uses new ransom notes.
It took the makers of the Jaff file-encrypting virus less than two weeks to contrive and launch a fresh edition of their nasty program. The bad news is that the upgrade appears to have brought about a significant refinement of the infection’s look and feel. As far as the functional stuffing goes, the ransomware in question is still uncrackable, just like its precursor. Let’s first take a look at what has changed. To begin with, victims’ files are now suffixed with the .wlu extension, which has taken over the previously used .jaff string. Also, the ransom how-to components that provide a walkthrough for data recovery are now named README_TO_DECRYPT.html, README_TO_DECRYPTl.txt, and README_TO_DECRYPTl.bmp. The latter, which is an image file, now replaces the desktop background with a warning followed by decryption steps.
One of the hallmarks that the two Jaff editions share is the distribution vector. The contagion is still malicious spam accompanied by a great deal of social engineering. The threat actors apparently rent a botnet, most likely a big one called Necurs, which spews out thousands of rogue emails in one hit. These booby-trapped emails are usually disguised as invoices from an inexistent customer service department. When a recipient tries to open the attached random-named PDF file, a dialog pops up with a recommendation to use Microsoft Word to proceed. Ultimately, the pseudo invoice turns out to be a .docm file that doesn’t render any content because it is allegedly protected. To read what’s inside, the unsuspecting user is instructed to click the Enable Content button on a security warning at the top of the window. This single click suffices for a VBA macro script to instantly install Jaff Decryptor onto the PC.
As soon as the bad code has been deposited onto the target system, it starts its foul play with an inconspicuous scan for hundreds of different file types that are subject to encryption. Then, it utilizes the AES cipher to lock all of these personal items down. This symmetric cryptosystem, the Advanced Encryption Standard, isn’t the strongest one imaginable. However, it still poses an unsurmountable obstacle to recovery as long as it’s implemented professionally – which unfortunately is the case with the Jaff virus. So the victim will discover that his or her important data is out of bounds. Again, a side effect of this scrambling routine is that files get appended with the .wlu extension, while the original filenames do not undergo any tweaks.
By navigating to the Tor gateway whose address is included in the README_TO_DECRYPT.html or README_TO_DECRYPTl.txt/bmp ransom notes, the infected user ends up on a Locky-style “Jaff Decryptor System” payment page. It provides tip on ways to purchase Bitcoins and indicates the size of the ransom, which can range from 0.35 BTC to as much as 2 BTC. This attack is certainly a serious predicament that requires urgent action. Whereas no effective free decryptor is available for the .wlu variant of Jaff ransomware at the time of this writing, it’s imperative to get rid of the perpetrating code proper. Furthermore, the data recovery methods below are also worthwhile as they may revive some files if the ransomware didn’t complete its crypto job.
Jaff .wlu files ransomware automated removal and data recovery
Owing to an up-to-date database of malware signatures and intelligent behavioral detection, the recommended software can quickly locate the infection, eradicate it and remediate all harmful changes. So go ahead and do the following:
1. Download and install the antimalware tool. Open the solution and have it check your PC for PUPs and other types of malicious software by clicking the Start Computer Scan button
2. Rest assured the scan report will list all items that may harm your operating system. Select the detected entries and click Fix Threats to get the troubleshooting completed.
Data recovery toolkit to the rescue
Some strains of ransomware are known to delete the original files after the encryption routine has been completed. As hostile as this activity appears, it can play into your hands. There are applications designed to revive the information that was obliterated because of malfunctioning hardware or due to accidental removal. The tool called Data Recovery Pro by ParetoLogic features this type of capability therefore it can be applied in ransom attack scenarios to at least get the most important files back. So download and install the program, run a scan and let it do its job.
.Wlu ransomware manual removal and file recovery
Some ransomware strains terminate themselves after completing the encryption job on a computer, but some don’t. Furthermore, the .wlu file virus may prevent victims from using popular antimalware tools in order to stay on board for as long as possible. Under the circumstances, it may be necessary to utilize the Safe Mode with Networking or System Restore functionality.
- Restart the machine. When the system begins loading back up, keep pressing the F8 key with short intervals. The Windows Advanced Options Menu (Advanced Boot Options) screen will appear.
- Use arrow keys to select Safe Mode with Networking and hit Enter. Log on with the user account infected by the ransomware.
- Click on the Search icon next to the Start menu button. Type msconfig in the search field and select the System Configuration option in the results. Go to the Boot tab in the upper part of the GUI.
- Under Boot options, select Safe boot and click the Apply button. A prompt will appear to reboot the computer so that the changes take effect. Select the Restart option and wait for the system to load into Safe Mode. Again, log on with the ransomware-stricken user account.
In Safe Mode, the ransom Trojan won’t keep security software from running or otherwise thwart troubleshooting. Open your preferred web browser, download and install an antimalware tool of choice and start a full system scan. Have all the detected ransomware components removed in a hassle-free way.
- Open Windows Advanced Options Menu as described in the previous section: hit F8 repeatedly when the PC is starting up. Use arrow keys to highlight the Safe Mode with Command Prompt entry. Hit Enter.
- In the Command Prompt window, type cd restore and hit Enter
- Type rstrui.exe in the new command line and press Enter
- When the System Restore screen pops up, click Next, select a restore point that predates the contamination, and use the application’s controls to roll back the system to this earlier state.
Be advised that even after the ransomware is removed, files will still be encrypted and inaccessible. The malicious code cleanup part, however, is important because it keeps a relapse of the infection from occurring further on and eliminates all opportunistic malware.
Ways of non-ransom recovery of .wlu extension files
Cracking the crypto used by this ransom Trojan is more of a science fiction thing rather than an attainable prospect for the masses. This is why the troubleshooting in predicaments of this sort is a matter of two approaches: one is to pay the ransom, which isn’t an option for many victims; and the other is to apply instruments that take advantage of the ransomware’s possible weaknesses. If the latter is your pick, the advice below is a must-try.
Checking one’s options regarding this workaround is doable in two ways: through the Properties menu of each file or by means of the remarkable open-source tool called Shadow Explorer. We recommend the software-based way because it’s automated, hence faster and easier. Just install the app and use its intuitive controls to get previous versions of the encrypted objects reinstated.
Alternatively, you can leverage the Previous Versions feature, which is native to Windows operating system. This method is more cumbersome that the use of ShadowExplorer, but it can help restore the most important individual files on condition that the ransomware failed to disable the Volume Snapshot Service on the computer. Right-click on a file of choice and select Properties. Then, go to the Previous Versions tab as illustrated below.
Go ahead and pick the file’s latest backup version on the list. Use the Copy or Restore buttons to reinstate this object to a new path or to its original folder, respectively.
Ransomware Prevention Tips
To avoid Jaff .wlu ransomware and other file-encrypting infections in the future, follow several simple recommendations:
- Toggle your email provider’s anti-spam settings to filter out all the potentially harmful incoming messages. Raising the bar beyond the default protection is an important countermeasure for ransom Trojans.
- Define specific file extension restrictions in your email system. Make sure that attachments with the following extensions are blacklisted: .js, .vbs, .docm, .hta, .exe, .cmd, .scr, and .bat. Also, treat ZIP archives in received messages with extreme caution.
- Rename the vssadmin.exe process so that ransomware is unable to obliterate all Shadow Volume Copies of your files in one shot.
- Keep your Firewall active at all times. It can prevent crypto ransomware from communicating with its C&C server. This way, the threat won’t be able to obtain cryptographic keys and lock your files.
- Back up your files regularly, at least the most important ones. This recommendation is self-explanatory. A ransomware attack isn’t an issue as long as you keep unaffected copies of your data in a safe place.
- Use an effective antimalware suite. There are security tools that identify ransomware-specific behavior and block the infection before it can do any harm.
These techniques are certainly not a cure-all, but they will add an extra layer of ransomware protection to your security setup.
Revise your security status
Post-factum assessment of the accuracy component in malware removal scenarios is a great habit that prevents the comeback of harmful code or replication of its unattended fractions. Make sure you are good to go by running an additional safety checkup.