A notorious data-encrypting threat is currently manifesting itself as Cerber Ransomware 5.0.1, the latest edition that creates the _README_.hta ransom note.
The Cerber ransomware keeps mutating to persevere with its successful deployment campaigns and continue to be a moving target for the IT security community. The new variant looks quite similar to its precursors on the outside, but turns out to have fundamental differences upon closer scrutiny. First of all, the desktop wallpaper with the ransom note now associates the attack with what’s called “Cerber Ransomware 5.0.1”. Secondly, the criminals have switched from using the README.hta recovery manual to one called _README_.hta.
Furthermore, Cerber 5.0.1 is being distributed through the aid of RIG-V, which is an advanced version of an infamous exploit kit available on darknet resources. This malware distribution toolset leverages the RC4 cryptographic algorithm to conceal perpetrating payloads, so it allows the ransomware to fly under the radar of antivirus suites as it’s trespassing on a computer.
One more noteworthy thing that changed in Cerber Ransomware 5.0.1 and the v5.0 series in general is the size of targeted files. Whereas the infection used to encrypt data objects as long as they were larger than 1,024 bytes, the updated version only zeroes in on files whose size is 2,560 bytes or more. Consequently, smaller entries are no longer at risk. Also, the developers of this malady have expanded the range of IP addresses applicable for transmitting UDP packets to the Command and Control server. When operating on a computer, this ransomware collects system statistics and establishes network communication to send them to the C2 so that the attackers on the backend can stay on top of all infection details.
The rest of the attack workflow is virtually the same as before. Cerber 5.0.1 contaminates Windows machines through a scheme that involves a network of compromised websites. When a user visits one of these pages, the above-mentioned RIG-V exploit kit hosted on it will find software vulnerabilities on the PC and harness them to stealthily inject the ransomware. This process is imperceptible to the naked eye, so the would-be victims don’t have much chance to notice and prevent the compromise.
Once on board a computer, the ransom Trojan finds all personal files on the hard drive, removable media and network shares. Then, it encrypts the data using a strong crypto algorithm. It also scrambles filenames according to the following pattern: [10 chars].[4-char extension]. The string of 4 hexadecimal characters, which replaces the original extension, actually matches the MachineGuid registry value. This parameter is unique for every PC. The ransom note named _README_.hta and the new desktop background instruct the victim to navigate to the Cerber Decryptor page using the Tor Browser. The page displays the amount of the ransom that the infected user has to pay to get the private decryption key. Normally, it is 1 BTC, or about $730. That’s the “special price” offer, though, which expires in 5 days. Afterward, the victim will be bound to submit 2 BTC.
In order to save yourself the trouble of redeeming your own files for that much money, keep your operating system and installed software up to date and do not browse to dubious web pages. The sections below contain some helpful tips in regards to restoring the encrypted files.
Cerber Ransomware 5.0.1 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.
Cerber 5.0.1 manual removal and file recovery
Some ransomware strains terminate themselves after completing the encryption job on a computer, but some don’t. Furthermore, Cerber v5.0.1 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 locked 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 Cerber Ransomware 5.0.1 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.