Mamba ransomware virus: what it is and how to remove it
Mamba ransomware is a file locking virus that deviated from Phobos ransomware, which incorporates a lot of similarities with Dharma/CrySiS virus. The malware mostly uses weak RDP connections to propagate, although other methods, like spam emails, exploit kits, fake updates, etc., might be used as well.
Facts checked October 7, 2026. Removal steps tested on Windows 11 (26H2) and checked against Microsoft's and the browser makers' current documentation. Sections marked as our earlier report are the original text: they describe the threat as it was then and have not been reviewed since. The 2026 status, the removal steps and the questions are current.
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Mamba ransomware virus: summary
| Detection names | No Microsoft detection name is known |
|---|---|
| Ransom note | info.txt; the text is quoted in full below |
| Contact | fileb@protonmail.com, back7@protonmail.ch, w889901665@yandex.com |
| Encrypted file extension | .phobos |
| Decryptor | No free decryptor is known for this variant; check No More Ransom (nomoreransom.org) for updates |
| Distribution | Not recorded in the old report |
| Removal | Scan the PC with security software to find and remove the malware and anything installed with it. Fortect scans Windows for malware and repairs the system files and settings it damaged. Remove it nowTo use the full-featured product, you have to purchase a license for Fortect. The scan is free. |
Show 10 more facts
| Damage | Not recorded in the old report |
|---|---|
| Name | Mamba ransomware virus |
| Type | File-encrypting ransomware |
| Symptoms | Files renamed with a new extension and a ransom note left in folders |
| Evidence | 11 write-ups by security sites; no sample analysed yet |
| Encrypted files | .phobos |
| Attacker contacts | fileb@protonmail.com |
| Free decryptor | No free decryptor is known (checked 7 October 2026) |
| First seen | 20 May 2019 |
| Facts checked | 7 October 2026 |
- File extension:
.phobos - Note file:
info.txt - Contact:
fileb@protonmail.com
From our report of May 2019 · not reviewed since
More from our earlier report on Mamba ransomware virus
- Personal files inaccessible, lock screen displayed at boot
- Can cause permanent data loss and system's crach
- 2016 against San Francisco's Municipal Transportation Agency 2017 attacked corporations in Brazil and Saudi Arabia New strains detected in 2018, though attacks haven't yet been executed
- At the beginning of April 2018, ransomware researchers found out an unusual ransomware sample, which has been recognized as HDDCrypt by BitDefender, Emsisoft, Symantec, ESET-NOD32, and other reputable AV engines.
The Mamba ransomware virus ransom note
"You are Hacked !
H.D.D.
Encrypted , Contact Us For Decryption Key (w889901665@yandex.com)
YOURID: [Victim's ID]"
How to remove Mamba ransomware virus
Tools you'll need
All of these are free except where noted. Download them on a clean device if the infected PC is offline.
- A USB stick: to keep the ransom note, two or three encrypted files and screenshots off the infected PC.
- Microsoft Defender Offline: built into Windows 11 and Windows 10; scans before Windows starts, so running malware cannot hide.
- Microsoft Safety Scanner: a second, portable scanner with current signatures; each download works for 10 days.
- ID Ransomware: identifies the family from the note and one encrypted file and says whether a decryptor exists.
- No More Ransom: the free decryptors from police and security companies; check it again every few months.
- Fortect (optional): scans Windows for malware and repairs the system files and settings it damaged. The free scan is in the box above.
How to remove Mamba ransomware virus and get your files back
Work in this order.
Disconnecting comes first, removal comes before any restore, and nothing here asks you to contact the attackers.
Step 1: Disconnect the PC and unplug backup drives
Unplug the network cable or turn off Wi-Fi, and disconnect USB drives, external disks and network shares, so Mamba ransomware virus cannot reach more files. Pause OneDrive, Google Drive or Dropbox sync, because synced folders upload the encrypted copies over the good ones.
Leave the PC on but offline while you read the next steps, since a restart can let the ransomware run again. This applies to Windows 11 and Windows 10 alike.
Windows 11: turn off Wi-Fi to take the PC offline. Full procedure with screenshots: Ransomware: first steps, finding a decryptor and recovering files
Step 2: Save the ransom note and confirm the family
Your files now end in
.phobosand the instructions are ininfo.txt. Save both to a USB stick, a copy of the note and two small encrypted files, before anything else.On another device, check them with ID Ransomware or Crypto Sheriff: the family name decides which decryptor, if any, can help. Keep the note's ID and contact line for your report.
Windows 11: the ransom note and encrypted files to copy for identification. Full procedure with screenshots: Ransomware: first steps, finding a decryptor and recovering files
Step 3: Check for a free decryptor
Our last check found that for Mamba ransomware virus, no free decryptor is known (checked 7 October 2026). Look again yourself in the No More Ransom list and the free decryptor pages of Emsisoft, Avast and Kaspersky, which add new families every year.
A decryptor needs the ransomware gone first, or it encrypts the files again. Keep at least one copy of the encrypted files on an external drive, even if no tool works yet.
Full procedure with screenshots: Ransomware: first steps, finding a decryptor and recovering files
Step 4: Remove the ransomware before you restore or decrypt
Removing Mamba ransomware virus does not bring the files back, but it has to come first. Start with Defender's Full scan, then the offline scan from the same Scan options page, which checks the disk before Windows loads.
If the scan cannot start, use Safe Mode with Networking. Delete the ransom notes only after you have saved a copy, because removal tools sometimes leave them behind on Windows 11 and Windows 10.
Windows 11: Windows Security > Virus & threat protection > Scan options. Full procedure with screenshots: Run a Microsoft Defender Offline scan
Step 5: Look for shadow copies of the files
Windows keeps shadow copies for restore points and backups, and some ransomware fails to delete them.
vssadmin list shadowsin an administrator Command Prompt tells you at once whether any exist.If they do, right-click the folder that held your files, open Properties > Previous Versions, select a version from before the attack, and click Open to check it before you Restore or copy the files out. Windows 11 and Windows 10 both have the tab.
Windows 11: vssadmin list shadows shows whether shadow copies exist. Full procedure with screenshots: Ransomware: first steps, finding a decryptor and recovering files
Step 6: Restore the files from a backup or recover deleted originals
A backup made before the attack is the surest way back. Connect it only once the PC is clean, then restore from File History, Windows Backup, OneDrive's Restore your OneDrive or your own external copies.
Without a backup, try file recovery: the originals that Mamba ransomware virus deleted may still be on the disk until something overwrites them. Install nothing new on the drive you want to recover from on the Windows 11 or Windows 10 PC.
Full procedure with screenshots: Recover deleted files (Recycle Bin, backups, OneDrive) On uGetFix
Instructions for each browser and system
The detailed steps for every browser and system this guide covers. Open the one you use.
Manual removal using Safe Mode
Important! →
Manual removal guide might be too complicated for regular computer users. It requires advanced IT knowledge to be performed correctly (if vital system files are removed or damaged, it might result in full Windows compromise), and it also might take hours to complete. Therefore, we highly advise using the automatic method provided above instead.
Step 1. Access Safe Mode with Networking
Manual malware removal should be best performed in the Safe Mode environment.
Windows 7 / Vista / XP
- Click Start > Shutdown > Restart > OK.
- When your computer becomes active, start pressing F8 button (if that does not work, try F2, F12, Del, etc. - it all depends on your motherboard model) multiple times until you see the Advanced Boot Options window.
- Select Safe Mode with Networking from the list.
Windows 10 / Windows 8
- Right-click on Start button and select Settings.
- Scroll down to pick Update & Security.
- On the left side of the window, pick Recovery.
- Now scroll down to find Advanced Startup section.
- Click Restart now.
- Select Troubleshoot.
- Go to Advanced options.
- Select Startup Settings.
- Press Restart.
- Now press 5 or click 5) Enable Safe Mode with Networking.
Step 2. Shut down suspicious processes
Windows Task Manager is a useful tool that shows all the processes running in the background. If malware is running a process, you need to shut it down:
- Press Ctrl + Shift + Esc on your keyboard to open Windows Task Manager.
- Click on More details.
- Scroll down to Background processes section, and look for anything suspicious.
- Right-click and select Open file location.
- Go back to the process, right-click and pick End Task.
- Delete the contents of the malicious folder.
Step 3. Check program Startup
- Press Ctrl + Shift + Esc on your keyboard to open Windows Task Manager.
- Go to Startup tab.
- Right-click on the suspicious program and pick Disable.
Step 4. Delete virus files
Malware-related files can be found in various places within your computer. Here are instructions that could help you find them:
- Type in Disk Cleanup in Windows search and press Enter.
- Select the drive you want to clean (C: is your main drive by default and is likely to be the one that has malicious files in).
- Scroll through the Files to delete list and select the following:
Temporary Internet Files
Downloads
Recycle Bin
Temporary files - Pick Clean up system files.
- You can also look for other malicious files hidden in the following folders (type these entries in Windows Search and press Enter):
%AppData%
%LocalAppData%
%ProgramData%
%WinDir%
After you are finished, reboot the PC in normal mode.
From our report of May 2019 · not reviewed since
Mamba ransomware is a file locking virus that not only locks up files but also rewrites Master Boot Record, preventing victims from entering the computer
Mamba ransomware is a file locking virus that deviated from Phobos ransomware, which incorporates a lot of similarities with Dharma/CrySiS virus.
The malware mostly uses weak RDP connections to propagate, although other methods, like spam emails, exploit kits, fake updates, etc., might be used as well.
Once inside, Mamba ransomware encrypts files on the local as well networked drives with the help of AES-2048 cipher. Initial variant of the virus used .phobos appendix, although other extensions were used later - .fendi, .phoenix, and others.
The latest version incorporates .id .[fileb@protonmail.com].mamba file extension, and drops info.txt/info.hta ransom note. After encrypting data, Mamba virus reboots the machine and prevents users from accessing the machine, as Master Boot Record is rewritten.
To decrypt data or even be able to enter the device, hackers behind Mamba ransomware ask victims to contact them via a variety of different emails, depending on the virus variant - the latest one asks users to write to fileb@protonmail.com or back7@protonmail.ch.
Unfortunately, there is currently no decryptor for this version available, but users can use alternative methods for data restore. Before that, however, the infected victims should remove Mamba ransomware from their device.
Mamba virus attacked San Francisco's Municipal Transportation Agency in November 2016 and asked to pay $73,000 ransom. In August 2017, ransomware came back and attacked several corporations in Brazil and Saudi Arabia.
Exhibiting modus operandi traits similar to Petya, Mamba ransomware targets data taking advantage of the DiskCryptor software. It is also known as HDD Cryptor, while the latest version known is dubbed as HDDCrypt. Detected at the end of March 2018, the virus does not deviate from its ancestors.
Reportedly, the virus drops 152.exe or 141.exe files on the computer, which are responsible for carrying out the encryption process. After encrypting victim's files, the virus reboots the computer and displays the following message on the boot screen:
The victim can enter the decryption password on the boot screen; however, he or she needs to get one first. Victims have to get in touch with malware authors and get information on how to decrypt data and get access to the computer again. This virus asks to pay a ransom of 1BTC per 1 host. The money should be transferred to a provided Bitcoin wallet.
However, we always recommend users NOT to pay the ransom since it gives no guarantee that files will be decrypted . Mamba removal is at utmost importance, and it should be completed using anti-malware tools, for example, or .
From our report of May 2019 · not reviewed since
2019: latest Mamba ransomware variants exploit weak RDPs for propagation
Mamba ransomware is based on Dharma, so its primary distribution method remains manual - breaking into the computers via RDP and installing the malware is something that hackers practice every time they detect a potential victim.
Once again, after several months of a break, Mamba ransomware returned at the end of 2018 and is being actively distributed since. Hackers use a variety of contact addresses and ask for a different amount of ransom inside ransom notes.
The latest variant of Mamba ransomware uses .id .[fileb@protonmail.com].mamba file extension and demands an unknown amount of payment in Bitcoin, which is declared once the victim contacts crooks via fileb@protonmail.com or back7@protonmail.ch email addresses. Additionally, hackers also offer a free decryption service for 5 files that cannot contain important information.
Nevertheless, the ransom should not be paid, as users should instead remove Mamba ransomware and use alternative file recovery methods.
From our report of May 2019 · not reviewed since
Experts warn about expected Mamba ransomware comeback in 2018
Mamba is not typical ransomware.
Its developers organize an outbreak against organizations and demand for huge ransom. Once collected, goes idle for a while. Silent since 2017 August, Mamba is expected to come back in the form of HDDCrypt ransomware.
The current version rewrites PC's Master Boot Record sectors and locks the user out of his or her PC. As we have already mentioned, the modus operandi of Mamba ransomware reminds the infamous Petya, as well as Satana. It uses AES-256-06 cipher to lock victims PCs and activates a pirated copy of the open source software DiskCryptor.
Luckily, Mamba ransomware HDDCrypt variant did not go wild. Most probably the ransomware is currently in the development phase, though people should be cautious. Do not download standalone file installers from suspicious sources, as well as freeware without checking the installation setup carefully. Finally, don't forget to install the latest updates for your OS and update the anti-virus program regularly.
From our report of May 2019 · not reviewed since
Mamba ransomware launched new attacks in August 2017
Mamba virus uses PSEXEC utility to install and run ransomware on the network.
The same behavior we have seen in NotPetya operation. When it compromises the network, it creates a C: \xampp\http folder where it installs DiskCryptor components. This utility is used for executing ransomware on the local computer.
This tool also generates unique passwords for each computer that are connected to the same network by executing this command:
One of the sneakiest features of the malware is that it installs itself as a Windows Service and hides itself under the DefragmentationService name. It also gets LocalSystem privileges, so Mamba gets full control over the computer.
When preparatory work is over, and all malicious components are installed on the system, malware reboots the affected device. Then it configures bootloader to Master Boot Record (MBR) and starts data encryption with DiskCryptor.
Mamba encrypts disk partitions and shows an unusual ransom note. Cyber criminals demand to contact them by one of the provided emails in order to get decryption key:
The ransom note also includes ransom unique victim's ID number. However, we highly recommend not wasting your time with communicating with criminals and following their demands. You should remove Mamba automatically and restore your files from backups or use alternative recovery methods.
- mcrytp2017@yandex.com
- citrix2234@protonmail.com
From our report of May 2019 · not reviewed since
Mamba hit public transit system of San Francisco in November 2016
At the end of November of 2016, Mamba ransomware managed to find its way to San Fransisco Municipal railway system servers and corrupt essential records with unbreakable encryption.
According to reports, the virus did hit 2,112 computers out of 8,656, blocking the email system, payment system and also railway scheduling system.
The virus displayed the same message on all railway system computers:
- You hacked
- all data encrypted
- contact for a key (cryptom27@yandex.ru)
Ransomware managed to take down ticket dispensers, too.
What is more, the author of the Mamba malware has responded to some journalists from San Fransisco newspaper, saying that he didn't intend to infect the railway system, but since it has already happened, the organization has to pay 100 Bitcoin ($73,000) to get the decryption software.
The author calls himself Any Saolis, but obviously, that is not the real perpetrator's name. What is more, the attacker disclosed that he has gained access to private company's documents and that he is going to publish them online if the railway company refuses to pay the ransom .
However, the company has already restored the system and confirmed that attackers didn't manage to access any sensitive data at all . The ransom wasn't paid.
From our report of May 2019 · not reviewed since
Distribution methods of the ransomware virus
The virus spreads like a Trojan horse, so the user can install it while thinking that it is a harmless file.
Consequently, it is highly recommended to stay away from sites that provide questionable downloads or show pop-up alerts stating that you need to update your software urgently. Such bogus updates typically contain malware.
Besides, ransomware threats frequently spread with the help of exploit kits. To prevent ransomware attacks, users should:
- protect their computers in advance by installing anti-malware programs,
- creating data backups,
- bypassing questionable sites on the Internet.
From our report of May 2019 · not reviewed since
Elimination instructions for the Mamba ransomware
To remove Mamba virus, just as we have said, it is strongly advisable to use anti-malware utility, such as or .
Unless you are an advanced IT expert, you should not try to carry out Mamba removal manually, because you risk to delete wrong files, leave virus' components and other unwanted components on the computer system.
Currently, the free Mamba decryption tool has not been found; therefore, the only way to restore files is to copy and paste them on the computer from a backup.
[GI=method-1]If you cannot run automatic Mamba elimination, follow these steps:
Although there is no free decryption tool released, please, do not panic and do not rush to pay the ransom. Criminals might send you an infectious file together with the decryption software, or provide no decryption tool at all.
You can wait, if you want - sometimes security experts manage to come up with free decryption tools in case they succeed to crack the ransomware code. Of course, you can recover files from backup disk or drive - just remove Mamba virus first.
Install this program using these instructions:
Mamba decryptor is not available yet
Report it and recover your files
Report it
Report the attack even if you do not expect the files back: insurers and banks ask for the report number, and police use the contacts in the note to link cases.
- United States
- FBI IC3 · FTC ReportFraud
- United Kingdom
- Report Fraud (formerly Action Fraud) · NCSC
- Australia
- ReportCyber (ASD)
- EU countries
- Europol: national reporting sites
Give the victim ID, the note and the date the files were encrypted. A business that holds personal data may also have to notify its data protection authority, in the EU within 72 hours.
Protect the files you restore
Restore only after the scans are clean and the PC no longer shows files that end in .phobos and no longer open; otherwise the restored copies can be damaged again.
Then build a backup that survives the next infection:
- one copy in the cloud with version history
- one on an external drive that is disconnected between backups
- the working copy on the PC
Version history matters because a backup that syncs damaged files overwrites the good ones.
How to do this with the tools built into Windows: the 3-2-1 backup rule on Windows.
Do not let government spy on you
The government has many issues in regards to tracking users' data and spying on citizens, so you should take this into consideration and learn more about shady information gathering practices.
Avoid any unwanted government tracking or spying by going totally anonymous on the internet.
You can choose a different location when you go online and access any material you want without particular content restrictions. You can easily enjoy internet connection without any risks of being hacked by using VPN.
Control the information that can be accessed by government any other unwanted party and surf online without being spied on. Even if you are not involved in illegal activities or trust your selection of services, platforms, be suspicious for your own security and take precautionary measures by using the VPN service.
Backup files for the later use, in case of the malware attack
Computer users can suffer from data losses due to cyber infections or their own faulty doings.
Ransomware can encrypt and hold files hostage, while unforeseen power cuts might cause a loss of important documents. If you have proper up-to-date backups, you can easily recover after such an incident and get back to work. It is also equally important to update backups on a regular basis so that the newest information remains intact - you can set this process to be performed automatically.
When you have the previous version of every important document or project you can avoid frustration and breakdowns. It comes in handy when malware strikes out of nowhere. Use for the data restoration process.
Questions about Mamba ransomware virus
How do I open .phobos files?
You cannot open them by renaming or with another program, because the content of files ending in .phobos has been encrypted. The only ways back are a working decryptor for the family, or clean copies from elsewhere:
- OneDrive versions
- File History
- an offline backup drive
- Previous Versions if the ransomware did not delete them
Identify the family first by uploading the ransom note and one encrypted file to ID Ransomware or No More Ransom. Avoid websites and programs that promise to open any encrypted file; they do not work and some are scams.
Is there a free Mamba ransomware virus decryptor?
We last checked on 7 October 2026, and for Mamba ransomware virus no free decryptor is known. We check No More Ransom, which collects free tools from police and security companies, and the decryptor pages of the major antivirus vendors. A working decryptor exists only when the encryption has a flaw or the keys were leaked or seized.
Ignore sites and videos that offer a "Mamba ransomware virus decryptor" for download or for a fee: these are usually scams or malware. Real decryptors are free and come from known security companies or law enforcement. Keep the encrypted files in case a tool appears later.
Should I pay the ransom?
We advise against it, and so do the FBI, Europol and national cyber agencies. Payment does not guarantee a working tool: some attackers never reply, some tools damage files, and some variants have no decryptor at all. Paying also funds further attacks and can make you a target again.
Before considering payment, try every recovery option in this guide and report the attack. Companies must involve their legal adviser and insurer, because payments to sanctioned groups can be illegal. If files are truly irreplaceable, store the encrypted copies and wait; decryptors sometimes appear later.
Can a data-recovery company decrypt my files for a fee?
Only if a decryptor already exists or the company pays the attackers for you. Some "ransomware recovery" services advertise that they can decrypt families with no known flaw; in practice they negotiate with the attackers and add their own fee. Others use the same free tools listed on No More Ransom.
Before you hire anyone, ask in writing how they will recover the files, whether they will contact the attackers and what happens if they fail. A legitimate service answers clearly. If a free decryptor exists for your family, you can run it yourself.
How did Mamba ransomware virus get on my computer?
The way Mamba ransomware virus spreads has not been documented yet, so look at your own recent activity. On home PCs, ransomware most often comes with cracked programs, game cheats, key generators and fake updates, or with an e-mail attachment that was opened. On business networks, attackers usually log in through Remote Desktop with a stolen or guessed password.
Think back to what was downloaded or installed in the days before files that end in .phobos and no longer open, and check the Downloads folder and Installed apps sorted by date. Keep anything suspicious for your report, but do not run it again.
Did Mamba ransomware virus steal my files or passwords?
We do not know yet. Nothing published so far shows data theft by Mamba ransomware virus, but the only confirmed sign is files that end in .phobos and no longer open, which says nothing about what happened before. Many current ransomware attacks copy files or run a password stealer first, so it is wise to act as if they did.
From a clean device, change the passwords that were saved in the browsers on this PC, starting with e-mail and banking, sign out of all sessions and turn on two-step verification. Watch bank statements and account activity for the next few weeks.
Is Mamba ransomware virus the same as other ransomware with a similar name?
Not necessarily. Ransomware names come from the file extension, the note or a word in the code, so unrelated families often end up with similar names, and one family can appear under several names. The difference matters: a decryptor or advice for one family does not fit another and can damage files.
Compare the ending added to your files and the exact name of the note with the summary table at the top of this guide, then upload the note and one encrypted file to ID Ransomware from a clean device. If the result names another family, follow the guide for that family instead.
What does info.txt tell me about the ransomware?
Quite a lot. The file name info.txt, the wording, the contact addresses and the format of the personal ID are typical for each family. Uploading the note together with one encrypted file to ID Ransomware or No More Ransom's Crypto Sheriff usually names the family within seconds.
That name decides your options: some families have free decryptors, some can be partially recovered, and some cannot be decrypted at all. The note's claims about stolen data should be taken seriously but not at face value.
Should I reinstall Windows after the .phobos attack?
Reinstalling removes the ransomware but not the encryption: your files ending in .phobos stay encrypted afterwards. So first copy the encrypted files and the ransom note to a separate drive, in case a decryptor appears later. Then decide:
- a clean-up with an offline scan is often enough for home PCs
- while a full reset is safer if remote access was involved
- scans keep finding new items
Restore your backups only after the PC is clean, and change passwords from another device.
Will Fortect remove Mamba ransomware virus?
Fortect scans Windows for malware and unwanted programs and repairs the system files and settings they change, and its free scan shows what it finds on your PC before you decide anything.
For Mamba ransomware virus, follow the plan above as well: the browser steps take back permissions and settings that no scanner treats as a threat, and uninstalling the program that brought it removes the source.
Run Microsoft Defender's full scan and, if anything was found, its offline scan as a second opinion. If the symptoms are gone after the plan and both scans are clean, there is nothing more to do.
Sources
- Twitter: #Phobos #Ransomware new extension (read October 7, 2026)
- SecureList: The return of Mamba ransomware (read October 7, 2026)
- Kaspersky Blog: Hospital learns the hard way why you don't pay ransomware crooks (read October 7, 2026)
- ZDNet: New Phobos ransomware exploits weak security to hit targets around the world (read October 7, 2026)
- Twitter: HDDCrypt (or Mamba) ransomware (read October 7, 2026)
- VirusTotal: File name bff29fd7fcc923087977aacec721e37e analysis (read October 7, 2026)