Kaspersky Lab researchers have discovered a new ransomware family deployed in targeted attacks against organizations. There are a couple of interesting things about this operation the payload of which is a slightly different Petya ransomware the researchers dubbed PetrWrap.
Threat Summary
| Name | PetrWrap |
| Type | Ransomware |
| Short Description | According to Kaspersky, PetrWrap is written in C and compiled in MS Visual Studio. It contains a sample of Petya v3 ransomware which is the payload of the operation. |
| Symptoms | Victim’s files are encrypted. The criminals used their own private and public keys. |
| Distribution Method | Organizations have been victimized in targeted attacks. |
| Detection Tool |
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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. |
| User Experience | Join Our Forum to Discuss PetrWrap. |
Update June 2017! Learn more about the latest variant of Petya ransomware – Petya.A/ WannaCry – known to use the EternalBlue exploit deployed in the WannaCry outbreak. This new variant is currently active so be sure to inform yourself about its specifics.
Once in an organization’s network, the attackers used the PsExec tool to install the ransomware payload – on all endpoints and servers. But it’s not your typical Petya RaaS payload. PetrWrap has a special module that “patches the original Petya ransomware on the fly”.
Related: Mischa Ransomware Bonds with Petya Ransomware
PetrWrap Ransomware: Technical Overview
Kaspersky’s report indicates that the ransomware is written in C and compiled in MS Visual Studio. It contains a sample of Petya v3 ransomware which is the payload of the whole operation.
PetrWrap uses its own cryptographic routines and alters the code of Petya on runtime. This is done so that the execution is controlled and Petya is concealed during the infection process.
After being launched PetrWrap delays its execution (sleeps for 5400 seconds = 1.5 hours). Then it decrypts the main DLL of Petya from its data section and gets ready to call its exported function ZuWQdweafdsg345312. This function normally prepares Petya for further operations and starts the MBR overwrite process. PetrWrap, however, needs to hook a couple of Petya’s functions first, so it replaces the instructions that call Petya’s DllEntryPoint with NOPs (hex bytes 0x90). This prevents Petya from proceeding on its own and allows PetrWrap to make all the necessary computations and preparations before letting it continue.
PetrWrap Cryptography
In a normal Petya ransomware infection the ransomware would deploy a 16-byte key and the Salsa20 cipher to encrypt the MFT of the NTFS partitions on local drives. In the case of PetrWrap, the criminals used their own private and public keys. As a result, the ransomware uses the following cryptographic routines, as explained by Kaspersky’s researchers:
- PetrWrap contains an embedded public key master_pub;
- Upon each individual infection, the ransomware generates a new pair of session keys ec_session_priv + ec_session_pub;
- The ransomware computes ecdh_shared_digest = SHA512(ECDH(master_pub, ec_session_priv));
- Then it ‘Intercepts’ the salsa key generated by Petya and encrypts it using ecdh_shared_digest;
- Then it constructs user_id, a string representation that contains the encrypted salsa key and the ec_session_pub;
- Finally, it passes this user_id to Petya, which uses it as if it was its own data.
In a nutshell, PetrWrap accomplishes the following list of activities:
1. The victim’s machine is locked and the MFT of NTFS partitions is encrypted securely (because Petya v3 which is used in this attack doesn’t have flaws of the earlier versions and implements Salsa20 correctly);
2. The lockscreen doesn’t show the flashing skull animation and doesn’t contain any mentions of Petya which makes it harder to assess the situation and determine the extent of the caused damage;
3. The developers of PetrWrap didn’t have to write the low-level bootloader code and risk making mistakes similar to the ones observed in earlier versions of Petya.
PetrWrap Decryption
Unfortunately, the strong encryption used by PetrWrap gets in the way of encryption. As Kaspersky researchers put it, “a decryption key is out of the question”. Victims of the ransomware are currently organizations but individuals may also be targeted. Ransomware is known to know no boundaries. If you have been victimized by PetrWrap, you could try and restore your files with third-party solutions but there is no guarantee they could work.
In the future, always remember to keep your system protected and your data properly backed up.
Spy Hunter scanner will only detect the threat. If you want the threat to be automatically removed, you need to purchase the full version of the anti-malware tool.Find Out More About SpyHunter Anti-Malware Tool / How to Uninstall SpyHunter
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Step 1: Scan for PetrWrap with SpyHunter Anti-Malware Tool
Ransomware Automatic Removal - Video Guide
Step 2: Uninstall PetrWrap and related malware 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:
Follow the instructions above and you will successfully delete most unwanted and malicious programs.
Step 3: Clean any registries, created by PetrWrap 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 PetrWrap there. This can happen by following the steps underneath:
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.
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: Boot Your PC In Safe Mode to isolate and remove PetrWrap
Step 5: Try to Restore Files Encrypted by PetrWrap.
Method 1: Use STOP Decrypter by Emsisoft.
Not all variants of this ransomware can be decrypted for free, but we have added the decryptor used by researchers that is often updated with the variants which become eventually decrypted. You can try and decrypt your files using the instructions below, but if they do not work, then unfortunately your variant of the ransomware virus is not decryptable.
Follow the instructions below to use the Emsisoft decrypter and decrypt your files for free. You can download the Emsisoft decryption tool linked here and then follow the steps provided below:
1 Right-click on the decrypter and click on Run as Administrator as shown below:
2. Agree with the license terms:
3. Click on "Add Folder" and then add the folders where you want files decrypted as shown underneath:
4. Click on "Decrypt" and wait for your files to be decoded.
Note: Credit for the decryptor goes to Emsisoft researchers who have made the breakthrough with this virus.
Method 2: Use data recovery software
Ransomware infections and PetrWrap 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.
Simply click on the link and on the website menus on the top, choose Data Recovery - Data Recovery Wizard for Windows or Mac (depending on your OS), and then download and run the tool.
PetrWrap-FAQ
What is PetrWrap Ransomware?
PetrWrap 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 algorithms 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.
What Does PetrWrap Ransomware Do?
Ransomware in general is a malicious software that is designed to block access to your computer or files until a ransom is paid.
Ransomware viruses can also damage your system, corrupt data and delete files, resulting in the permanent loss of important files.
How Does PetrWrap Infect?
Via several ways.PetrWrap Ransomware infects computers by being sent via phishing emails, 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.
Another way you may become a victim of PetrWrap 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 .PetrWrap files?
You can't without a decryptor. At this point, the .PetrWrap files are encrypted. You can only open them once they are decrypted using a specific decryption key for the particular algorithm.
What to Do If a Decryptor Does Not Work?
Do not panic, and backup the files. If a decryptor did not decrypt your .PetrWrap files successfully, then do not despair, because this virus is still new.
Can I Restore ".PetrWrap" Files?
Yes, sometimes files can be restored. We have suggested several file recovery methods that could work if you want to restore .PetrWrap files.
These methods are in no way 100% guaranteed that you will be able to get your files back. But if you have a backup, your chances of success are much greater.
How To Get Rid of PetrWrap Virus?
The safest way and the most efficient one for the removal of this ransomware infection is the use a professional anti-malware program.
It will scan for and locate PetrWrap ransomware and then remove it without causing any additional harm to your important .PetrWrap files.
Can I Report Ransomware to Authorities?
In case your computer got infected with a ransomware infection, you can report it to the local Police departments. It can help authorities worldwide track and determine the perpetrators behind the virus that has infected your computer.
Below, we have prepared a list with government websites, where you can file a report in case you are a victim of a cybercrime:
Cyber-security authorities, responsible for handling ransomware attack reports in different regions all over the world:
Germany - Offizielles Portal der deutschen Polizei
United States - IC3 Internet Crime Complaint Centre
United Kingdom - Action Fraud Police
France - Ministère de l'Intérieur
Italy - Polizia Di Stato
Spain - Policía Nacional
Netherlands - Politie
Poland - Policja
Portugal - Polícia Judiciária
Greece - Cyber Crime Unit (Hellenic Police)
India - Mumbai Police - CyberCrime Investigation Cell
Australia - Australian High Tech Crime Center
Reports may be responded to in different timeframes, depending on your local authorities.
Can You Stop Ransomware from Encrypting Your Files?
Yes, you can prevent ransomware. The best way to do this is to ensure your computer system is updated with the latest security patches, use a reputable anti-malware program and firewall, backup your important files frequently, and avoid clicking on malicious links or downloading unknown files.
Can PetrWrap Ransomware Steal Your Data?
Yes, in most cases ransomware will steal your information. It is a form of malware that steals data from a user's computer, encrypts it, and then demands a ransom in order to decrypt it.
In many cases, the malware authors or attackers will threaten to delete the data or publish it online unless the ransom is paid.
Can Ransomware Infect WiFi?
Yes, ransomware can infect WiFi networks, as malicious actors can use it to gain control of the network, steal confidential data, and lock out users. If a ransomware attack is successful, it could lead to a loss of service and/or data, and in some cases, financial losses.
Should I Pay Ransomware?
No, you should not pay ransomware extortionists. Paying them only encourages criminals and does not guarantee that the files or data will be restored. The better approach is to have a secure backup of important data and be vigilant about security in the first place.
What Happens If I Don't Pay Ransom?
If you don't pay the ransom, the hackers may still have access to your computer, data, or files and may continue to threaten to expose or delete them, or even use them to commit cybercrimes. In some cases, they may even continue to demand additional ransom payments.
Can a Ransomware Attack Be Detected?
Yes, ransomware can be detected. Anti-malware software and other advanced security tools can detect ransomware and alert the user when it is present on a machine.
It is important to stay up-to-date on the latest security measures and to keep security software updated to ensure ransomware can be detected and prevented.
Do Ransomware Criminals Get Caught?
Yes, ransomware criminals do get caught. Law enforcement agencies, such as the FBI, Interpol and others have been successful in tracking down and prosecuting ransomware criminals in the US and other countries. As ransomware threats continue to increase, so does the enforcement activity.
About the PetrWrap Research
The content we publish on SensorsTechForum.com, this PetrWrap how-to removal guide included, is the outcome of extensive research, hard work and our team’s devotion to help you remove the specific malware and restore your encrypted files.
How did we conduct the research on this ransomware?
Our research is based on an independent investigation. We are in contact with independent security researchers, and as such, we receive daily updates on the latest malware and ransomware definitions.
Furthermore, the research behind the PetrWrap ransomware threat is backed with VirusTotal and the NoMoreRansom project.
To better understand the ransomware threat, please refer to the following articles which provide knowledgeable details.
As a site that has been dedicated to providing free removal instructions for ransomware and malware since 2014, SensorsTechForum’s recommendation is to only pay attention to trustworthy sources.
How to recognize trustworthy sources:
- Always check "About Us" web page.
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