Snatch ransomware – reboots Windows computers into Safe Mode then encrypts victims’ files – how to remove it

0
507

Cybersecurity researchers have spotted a new variant of the Snatch ransomware that first reboots infected Windows computers into Safe Mode and only then encrypts victims’ files to avoid antivirus detection.

Unlike traditional malware, the new Snatch ransomware chooses to run in Safe Mode because in the diagnostic mode Windows operating system starts with a minimal set of drivers and services without loading most of the third-party startup programs, including antivirus software.

Snatch has been active since at least the summer of 2018, but SophosLabs researchers spotted the Safe Mode enhancement to this ransomware strain only in recent cyber attacks against various entities they investigated.

“SophosLabs researchers have been investigating an ongoing series of ransomware attacks in which the ransomware executable forces the Windows machine to reboot into Safe Mode before beginning the encryption process,” the researchers say.

“The ransomware, which calls itself Snatch, sets itself up as a service [called SuperBackupMan with the help of Windows registry] that will run during a Safe Mode boot.”

“When the computer comes back up after the reboot, this time in Safe Mode, the malware uses the Windows component net.exe to halt the SuperBackupMan service, and then uses the Windows component vssadmin.exe to delete all the Volume Shadow Copies on the system, which prevents forensic recovery of the files encrypted by the ransomware.”

What makes Snatch different and dangerous from others is that in addition to ransomware, it’s also a data stealer.

Snatch includes a sophisticated data-stealing module, allowing attackers to steal vast amounts of information from the target organizations.

Though Snatch is written in Go, a programming language known for cross-platform app development, the authors have designed this ransomware to run only on the Windows platform.

“Snatch can run on most common versions of Windows, from 7 through 10, in 32- and 64-bit versions. The samples we’ve seen are also packed with the open source packer UPX to obfuscate their contents,” the researchers say.

Besides this, the attackers behind Snatch ransomware also offer partnership opportunities to other cybercriminals and rogue employees who possess credentials and backdoors into large organizations and can exploit it to deploy the ransomware.

As shown in the screenshot taken from an underground forum, one of the group members posted an offer “looking for affiliate partners with access to RDP \ VNC \ TeamViewer \ WebShell \ SQL injection in corporate networks, stores, and other companies.”

Snatch Ransomware Attack

Using brute-forced or stolen credentials, attackers first gain access to the company’s internal network and then run several legitimate system administrators and penetration testing tools to compromise devices within the same network without raising any red flag.

“We also found a range of otherwise legitimate tools that have been adopted by criminals installed on machines within the target’s network, including Process Hacker, IObit Uninstaller, PowerTool, and PsExec.

The attackers typically use them to try to disable AV products,” the researchers say.

Coveware, a company that specializes in extortion negotiations between attackers and ransomware victims, told Sophos that they negotiated with the Snatch criminals “on 12 occasions between July and October 2019 on behalf of their clients” with the ransom payments ranging between $2,000 to $35,000 in bitcoins.

To prevent ransomware attacks, organizations are recommended not to expose their critical services and secure ports to the public Internet, and if required, secure them using a strong password with multi-factor authentication.

STEALING CUSTOMER DATA

Furthermore, Sophos says that unlike most ransomware gangs who are primarily focused on encrypting files and asking for ransoms, they also found evidence the Snatch crew also enganged in data theft.

This makes the Snatch crew unique and highly dangerous, as companies also stand to lose from their data being sold or leaked online at a later date, even if they paid the ransom fee and decrypted their files.

This type of behavior is highly unusual and is likely to push Snatch at the top of many lists of today’s most dangerous ransomware strains.

But combing a company’s internal network for files to steal takes time, and a reason why Snatch has not made the same amount of victims as other “big game hunting” strains/gangs. The number of Snatch victims is very small.

Coverware, a company that specializes in extortion negotiations between ransomware victims and attackers, told Sophos they’ve privately handled ransom payments for Snatch ransomware infections on 12 occasions between July and October 2019. The payments ranged from $2,000 to $35,000, Coverware said.

Until today, the only known public case of a Snatch ransomware infection was SmarterASP.NET, a web hosting company that boasted to have around 440,000 customers.

Sophos recommends that companies secure ports and services that are exposed on the internet with either strong passwords or with multi-factor authentication.

Since the Snatch crew is also interested in experimenting with VNC, TeamViewer, or SQL injections, securing a company’s network for these attack points is also a must.

ATTACK HAPPENED ON SATURDAY

The attack didn’t just hit customer data, but also SmarterASP.NET itself. The company’s website was down all day on Saturday, coming back online earlier today on Sunday morning.

Server recovery efforts are going slow. Many customers still don’t have access to their accounts and data. Those who do say their data is still encrypted, including website files but also backend databases.

While most users where using SmarterASP.NET for hosting ASP.NET sites, some were using the company’s serves as app backends, where they were synchronizing or backing up important data. The fact that backend databases have also been hit, and not just public-facing web servers, has prevented many from moving impacted services to alternative IT infrastructure.

According to screenshots posted on Twitter, all customer files have been encrypted by a version of the Snatch ransomware that encrypts files with a “.kjhbx” file extension.

smartaspnet-ransom-extension.png
Image via Twitter user @calamitatum
smartaspnet-ransom-note-text.jpg
Image via Twitter user Ailin Albertoni (@ailinalbertoni)

SmarterASP.NET is the third hosting provider that was hit this year. The first was A2 Hosting in May. A2, a well-known provider of Windows Servers, had servers in Asia and North America encrypted by a version of the GlobeImposter 2.0 ransomware strain.

The second web hosting provider hit this year was iNSYNQ, a cloud computing provider of virtual desktop environments. The company was infected in mid-July by a version of the MegaCortex ransomware.

Both A2 and iNSYNQ took weeks to restore and fully recover customer data. Due to the sheer size of its customer base, SmarterASP.NET seems to be on point for a similar recovery timeline.

It should be no surprise that ransomware gangs are looking to infect web hosting providers. To this day, the largest ransomware payment ever made came from a web hosting provider.

This “honor” goes to South Korean web hosting firm Internet Nayana, which paid 1.3 billion won ($1.14 million) worth of bitcoins to a hacker following a ransomware incident in June 2017.


Snatch ransomware removal instructions

What is Snatch?

Discovered by Michael Gillespie, Snatch is high-risk computer infection categorized as ransomware. Programs of this type are developed by cyber criminals. They use ransomware to encrypt data stored on computers and blackmail victims by demanding ransom payments. Snatch creates a ransom message within a text file called “Readme_Restore_Files.txt” and renames encrypted files by adding the “.snatch” extension. For example, “1.jpg” becomes “1.jpg.snatch“.

Snatch developers (cyber criminals) claim in the “Readme_Restore_Files.txt” that all data stored on the victim’s computer is encrypted. They warn victims not to modify any encrypted files. The [email protected] email address is provided to contact developers of Snatch ransomware. No other statements are made within the ransom message. Once contacted, cyber ransomware developers generally demand payment of a ransom.

They state the cost of a decryption tool and send a cryptocurrency wallet address to make the transaction. Ransomware-type programs commonly encrypt data using cryptography algorithms (symmetric or asymmetric) that cannot be ‘cracked’ without using a specific decryption tool. Unfortunately, in most cases, only ransomware developers can provide victims with a tool capable of decryption.

Note that they do not provide these tools free of charge. Generally, cyber criminals cannot be trusted – they send no decryption tools, even if their ransom demands are met. There are no free tools capable of decrypting files encrypted by Snatch (at least, not at the moment). If you have a data backup created before the computer was infected by this ransomware, we recommend that you use it to restore your files.

Screenshot of a message encouraging users to pay a ransom to decrypt their compromised data:

Snatch decrypt instructions

Snatch is one of many ransomware-type programs. Other examples include SEED LOCKER, GANDCRAB 5.2 (one of many versions), and Cammora. 

Generally, these programs encrypt data and display ransom demand messages. Any differences are cost of decryption and cryptography algorithm used for encryption. Most encryptions are impossible to crack without using the tools owned by specific ransomware developers.

Decryption is only possible in rare cases when ransomware-type programs are not fully developed, contain bugs/flaws, and so on. To avoid data loss caused by ransomware in the future, create data backups and store them on remote servers or unplugged storage devices.

How did ransomware infect my computer?

Ransomware-type programs and other computer infections are usually distributed using spam campaigns (emails), untrustworthy software download channels, Trojans, software cracking tools, and fake updaters. Cyber criminals proliferate these infections by presenting malicious email attachments (or links) as legitimate.

The main goal is to trick recipients into opening malicious attachments or website links that leads to them. Opening these attachments leads to installation of malicious programs. Attached files are usually Microsoft Office documents, executables (.exe), archives (RAR and other), JavaScript files, and so on. Untrustworthy software download sources such as Peer-to-Peer networks (torrent clients, eMule and other), freeware download and free file hosting websites, third party software downloaders/installers type are also used to proliferate malware.

Cyber criminals use them to present malicious files as legitimate. By downloading and running them, users often install various viruses. Trojans are malicious programs that proliferate other computer infections.

If a trojan is installed, other infections are caused. To proliferate ransomware, cyber criminals use software cracking tools – these often install malicious programs rather than activating any software free of charge. Fake software updaters usually infect systems by exploiting outdated software bugs/flaws or by downloading infections rather than updates or fixes.

NameSnatch virus
Threat TypeRansomware, Crypto Virus, Files locker
Encrypted Files Extension.snatch, .wvtr0
Ransom Demanding MessageReadme_Restore_Files.txt, RESTORE_WVTR0_FILES.txt
Cyber Criminal Contact[email protected], [email protected]
Cyber Criminal Cryptowallet Address1HsobDYQrg6U1X8uDjQFFFjoSAFVFhHgKU (Bitcoin)
Detection Names (updated variant)
Avast (Win64:Malware-gen), BitDefender (Gen:Variant.Ransom.Snatch.1), ESET-NOD32 (A Variant Of Win64/Filecoder.AM), Kaspersky (Trojan.Win32.DelShad.ea), Full List Of Detections (VirusTotal)
Rogue Process Namewvtr0x64.exe (the process name may vary)
SymptomsCannot open files stored on your computer, previously functional files now have a different extension (for example, my.docx.locked). A ransom demand message is displayed on your desktop. Cyber criminals demand payment of a ransom (usually in bitcoins) to unlock your files.
Distribution methodsInfected email attachments (macros), torrent websites, malicious ads.
DamageAll files are encrypted and cannot be opened without paying a ransom. Additional password-stealing trojans and malware infections can be installed together with a ransomware infection.
RemovalTo eliminate Snatch virus our malware researchers recommend scanning your computer with Spyhunter.
Free scanner checks if your computer is infected. To remove malware, you have to purchase the full version of Spyhunter.

How to protect yourself from ransomware infections?

Avoid opening attachments or links that are presented in emails received from unknown, untrustworthy or suspicious email addresses. These emails are usually presented as important and official, however, do not open any attachments or click website links. Download software using direct links and trustworthy, official sources. Do not use Peer-to-Peer networks, third party downloaders, installers, or other dubious sources.

These sources are often used to promote rogue apps capable of causing computer infections or other serious problems. Installed software or operating systems should be updated using tools or implemented functions provided by official software developers. Software cracking tools cannot be trusted, since they are illegal (using them is a cyber crime) and they often cause computer infections. To keep your computer safe, have a reputable anti-virus or anti-spyware suite installed and keep it enabled at all times.

These tools usually detect and eliminate threats before they can do any damage. If your computer is already infected with Snatch, we recommend running a scan with Spyhunter for Windows to automatically eliminate this ransomware.

Text presented in Snatch ransomware text file (“Readme_Restore_Files.txt“):

All your files are encrypted
Do not try modify files
My email [email protected]

Screenshot of files encrypted by Snatch (“.snatch” extension):

Files encrypted by Snatch

Update November 28, 2019 – Crooks have recently released an updated version of Snatch ransomware which now appends “.wvtr0” extension and drops a completely different ransom note –  “RESTORE_WVTR0_FILES.txt“.

Screenshot of updated Snatch ransomware’s text file (“RESTORE_WVTR0_FILES.txt“):

Updated Snatch ransomware ransom note
Text presented within this file: 
Attention!
Do not rename the ciphered files
Do not try to decrypt your data of the third-party software, it can cause constant data loss
You do not joke with files

To restore your files visit "hxxp://mydatasuperhero.com" website. This website is safe
If this website is not available use reserve website "hxxp://snatch24uldhpwrm.onion" in a TOR network. This website is safe. For visit of this website it is necessary to install Tor browser (hxxps://www.torproject.org)

Your login: -
Your password: -
Your BTC address: 1HsobDYQrg6U1X8uDjQFFFjoSAFVFhHgKU

If all websites are not available write to us on email of [email protected]

You keep this information in secret

Screenshot of files encrypted by the updated Snatch ransomware (“.wvtr0” extension):

Files encrypted by the updated Snatch ransomware

Process (“wvtr0x64.exe“) of updated Snatch ransomware in Windows Task Manager:

Process of updated Snatch ransomware in Windows Task Manager

Snatch ransomware removal:

Instant automatic removal of Snatch virus:Manual threat removal might be a lengthy and complicated process that requires advanced computer skills.

Spyhunter is a professional automatic malware removal tool that is recommended to get rid of Snatch virus.

Quick menu:

  • What is Snatch?
  • STEP 1. Snatch virus removal using safe mode with networking.
  • STEP 2. Snatch ransomware removal using System Restore.

Step 1

Windows XP and Windows 7 users: Start your computer in Safe Mode. Click Start, click Shut Down, click Restart, click OK. During your computer start process, press the F8 key on your keyboard multiple times until you see the Windows Advanced Option menu, and then select Safe Mode with Networking from the list.

Safe Mode with Networking

Video showing how to start Windows 7 in “Safe Mode with Networking”:

Windows 8 users: Start Windows 8 is Safe Mode with Networking – Go to Windows 8 Start Screen, type Advanced, in the search results select Settings. Click Advanced startup options, in the opened “General PC Settings” window, select Advanced startup. Click the “Restart now” button. Your computer will now restart into the “Advanced Startup options menu”. Click the “Troubleshoot” button, and then click the “Advanced options” button. In the advanced option screen, click “Startup settings”. Click the “Restart” button. Your PC will restart into the Startup Settings screen. Press F5 to boot in Safe Mode with Networking.

Windows 8 Safe Mode with networking

Video showing how to start Windows 8 in “Safe Mode with Networking”:

Windows 10 users: Click the Windows logo and select the Power icon. In the opened menu click “Restart” while holding “Shift” button on your keyboard. In the “choose an option” window click on the “Troubleshoot”, next select “Advanced options”. In the advanced options menu select “Startup Settings” and click on the “Restart” button. In the following window you should click the “F5” button on your keyboard. This will restart your operating system in safe mode with networking.

windows 10 safe mode with networking

Video showing how to start Windows 10 in “Safe Mode with Networking”:

Step 2

Log in to the account infected with the Snatch virus. Start your Internet browser and download a legitimate anti-spyware program. Update the anti-spyware software and start a full system scan. Remove all entries detected.

Free scanner checks if your computer is infected. To remove malware, you have to purchase the full version of Spyhunter.

If you cannot start your computer in Safe Mode with Networking, try performing a System Restore.

Video showing how to remove ransomware virus using “Safe Mode with Command Prompt” and “System Restore”:

1. During your computer start process, press the F8 key on your keyboard multiple times until the Windows Advanced Options menu appears, and then select Safe Mode with Command Prompt from the list and press ENTER.

Boot your computer in Safe Mode with Command Prompt

2. When Command Prompt mode loads, enter the following line: cd restore and press ENTER.

system restore using command prompt type cd restore

3. Next, type this line: rstrui.exe and press ENTER.

system restore using command prompt rstrui.exe

4. In the opened window, click “Next”.

restore system files and settings

5. Select one of the available Restore Points and click “Next” (this will restore your computer system to an earlier time and date, prior to the Snatch ransomware virus infiltrating your PC).

select a restore point

6. In the opened window, click “Yes”.

run system restore

7. After restoring your computer to a previous date, download and scan your PC with recommended malware removal software to eliminate any remaining Snatch ransomware files.

To restore individual files encrypted by this ransomware, try using Windows Previous Versions feature. This method is only effective if the System Restore function was enabled on an infected operating system. Note that some variants of Snatch are known to remove Shadow Volume Copies of the files, so this method may not work on all computers.

To restore a file, right-click over it, go into Properties, and select the Previous Versions tab. If the relevant file has a Restore Point, select it and click the “Restore” button.

Restoring files encrypted by CryptoDefense

If you cannot start your computer in Safe Mode with Networking (or with Command Prompt), boot your computer using a rescue disk. Some variants of ransomware disable Safe Mode making its removal complicated. For this step, you require access to another computer.

To regain control of the files encrypted by Snatch, you can also try using a program called Shadow Explorer. More information on how to use this program is available here.

shadow explorer screenshot

To protect your computer from file encryption ransomware such as this, use reputable antivirus and anti-spyware programs. As an extra protection method, you can use programs called HitmanPro.Alert and EasySync CryptoMonitor, which artificially implant group policy objects into the registry to block rogue programs such as Snatch ransomware.

Note that Windows 10 Fall Creators Update includes a “Controlled Folder Access” feature that blocks ransomware attempts to encrypt your files. By default, this feature automatically protects files stored in the Documents, Pictures, Videos, Music, Favorites as well as Desktop folders.

Controll Folder Access

Windows 10 users should install this update to protect their data from ransomware attacks. Here is more information on how to get this update and add an additional protection layer from ransomware infections.

HitmanPro.Alert CryptoGuard – detects encryption of files and neutralises any attempts without need for user-intervention:

hitmanproalert ransomware prevention application

Malwarebytes Anti-Ransomware Beta uses advanced proactive technology that monitors ransomware activity and terminates it immediately – before reaching users’ files:

malwarebytes anti-ransomware
  • The best way to avoid damage from ransomware infections is to maintain regular up-to-date backups.

Other tools known to remove Snatch ransomware:

  • Malwarebytes Anti-Malware

LEAVE A REPLY

Please enter your comment!
Please enter your name here

Questo sito usa Akismet per ridurre lo spam. Scopri come i tuoi dati vengono elaborati.