Gachimuchi virus: what it is and how to remove it
Gachimuchi ransomware is a data-encrypting virus that targets Windows machines. The malware was first observed making rounds in the middle of June 2022, although it does not seem to belong to either of the bigger ransomware strains.
Facts checked October 6, 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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Gachimuchi virus: summary
| Name | Gachimuchi virus |
|---|---|
| Type | Ransomware, file-locking malware |
| File extension | [ID].[BillyHerrington].Gachimuchi |
| Ransom note | #HOW_TO_DECRYPT#.txt |
| Contact | @Gachimuchi on ICQ or gachimuchi@onionmail.org |
| File Recovery | The only secure way to restore files is by using data backups. If such is not available or were encrypted as well, options for recovery are very limited – we provide all possible solutions below |
| 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 12 more facts
| Detection names | No Microsoft detection name is known |
|---|---|
| Encrypted file extension | .gachimuchi |
| Decryptor | No free decryptor is known for this variant; check No More Ransom (nomoreransom.org) for updates |
| Distribution | Not recorded in the old report |
| Damage | Not recorded in the old report |
| Symptoms | Files renamed with a new extension and a ransom note left in folders |
| Evidence | 4 write-ups by security sites; no sample analysed yet |
| Encrypted files | .gachimuchi |
| Attacker contacts | gachimuchi@onionmail.org |
| Free decryptor | No free decryptor is known (checked 6 October 2026) |
| First seen | 14 June 2022 |
| Facts checked | 6 October 2026 |
- File extension:
.gachimuchi - Note file:
HOW_TO_DECRYPT#.txt - Contact:
gachimuchi@onionmail.org
From our report of Jun 2022 · not reviewed since
More from our earlier report on Gachimuchi virus
- Disconnect the computer from the network and internet and then perform a full system scan with security software
- Once installed on the system, malware might seriously damage some system files, resulting in crashes, errors, and other stability issues.
- You can employ PC repair to fix any of such damage automatically by replacing system corruption
- Free Ransomware Decryptors by Kaspersky
How Gachimuchi virus behaves
From our report of Jun 2022 · not reviewed since
Gachimuchi ransomware encrypts your files to later ask for a ransom from you
Gachimuchi ransomware is a data-encrypting virus that targets Windows machines.
The malware was first observed making rounds in the middle of June 2022, although it does not seem to belong to either of the bigger ransomware strains.
Once on the system, the virus would encrypt pictures, videos, music, documents, databases, and other valuable files by using a strong encryption algorithm, making the data completely useless. During this time, each of the personal files acquires a ".Gachimuchi" extension, along with additional affixes consisting of personal ID and "BillyHerrington."
It is worth noting that files affected by ransomware are not corrupted (even if it may seem so) but rather locked behind a special, unique password based on a long string of alphanumeric characters. It is impossible to guess it or acquire it in any other way - it is stored on cybercriminals' servers.
It is not surprising that Gachimuchi ransomware authors are unwilling to give the decryption key for free, and demand a ransom to be paid in exchange. According to the #HOW_TO_DECRYPT#.txt ransom note, victims should contact crooks via @Gachimuchi on ICQ or using the gachimuchi@onionmail.org email. Avoid any contact with ransomware developers and instead, use alternative solutions we provide below.
From our report of Jun 2022 · not reviewed since
Ransom note explained
The ransom note has become an integral part of ransomware's operation.
It provides all the crucial information that victims should know; it includes an explanation of what happened to their files, what they need to do to retrieve them, and how to contact the attackers. Usually, the note is delivered in a simple TXT format for users to easily access the important information - as is the case with the Gachimuchi virus.
The data encryption process usually lasts mere seconds before its complete and after assigning a unique ID to the affected machine, malware delivers the #HOW_TO_DECRYPT#.txt ransom note, which reads:
It is interesting how the attackers claim they value the "reputation of the company," completely disregarding the fact that infecting users' machines with malware is despicable and illegal. Communicating with crooks only assures them that their illegal business works as intended and only prompts them to infect more victims in the future. This is one of many reasons why the FBI and other authorities recommend not paying the ransom.
The Gachimuchi virus ransom note
ALL YOUR DOCUMENTS PHOTOS DATABASES AND OTHER IMPORTANT FILES HAVE BEEN ENCRYPTED!
========================
Your files are NOT damaged! Your files are modified only. This modification is reversible.
The only 1 way to decrypt your files is to receive the private key and decryption program.
Any attempts to restore your files with the third party software will be fatal for your files!
========================
To receive the private key and decryption program follow the instructions below:
1. Write to our skype - Gachimuchi DECRYPTION
Also you can write ICQ live chat which works 24/7 @Gachimuchi
Install ICQ software on your PC https://icq.com/windows/ or on your mobile phone search in Appstore / Google market ICQ
Write to our ICQ @Gachimuchi https://icq.im/Gachimuchi
If we not reply in 6 hours you can write to our mail but use it only if previous methods not working - gachimuchi@onionmail.org
2. Our company values its reputation. We give all guarantees of your files decryption,such as test decryption some of them
We respect your time and waiting for respond from your side
tell your MachineID: and LaunchID:
========================
How to remove Gachimuchi 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 Gachimuchi 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 Gachimuchi 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
.gachimuchiand the instructions are inHOW_TO_DECRYPT#.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 Gachimuchi virus, no free decryptor is known (checked 6 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 Gachimuchi 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 Gachimuchi 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
From our report of Jun 2022 · not reviewed since
Gachimuchi ransomware removal
The first task is to make sure that the malware and all its components are removed from the system thoroughly, and for that, you need , , or another powerful anti-malware solution.
Manual elimination is possible, although it is not recommended, as it requires extensive IT knowledge. Besides, failing to remove all ransomware components might result in incoming data encryption and system reinfection.
If Gachimuchi virus removal is being tampered with, you should access Safe Mode and eliminate the infection from there. Please follow the following steps to reach the mode where malware's operation is temporarily suspended:
Windows 7 / Vista / XP
Windows 10 / Windows 8
- Click Start > Shutdown > Restart > OK.
- When your computer becomes active, start pressing the 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.
- Right-click on the Start button and select Settings.
- On the left side of the window, pick Recovery.
- Click Restart now.
- Select Troubleshoot.
- Go to Advanced options.
- Select Startup Settings.
- Click Restart.
- Press 5 or click 5) Enable Safe Mode with Networking.
From our report of Jun 2022 · not reviewed since
Data recovery
Some users believe that Gachimuchi files can be restored as soon as the computer scan with security software is performed.
However, it is not the case, as data encryption is rather permanent - at least until a unique key is applied. It is also not correct to believe that the files are damaged or corrupted, as encryption does not essentially damage files.
As we already mentioned, it is not recommended to contact crooks. Instead, alternative methods could help you restore at least some of the lost data. Before proceeding, make sure you make backups of the encrypted files, as tampering with them might corrupt them for good.
Security experts are known to work on decryption tools for major ransomware strains. In some cases, flaws within the encryption process can be found or criminals' servers seized by the lay authority agencies. In any case, you could look for decryptors on the following pages, although keep in mind it might take a while until there's a working one made.
- Download .
- Double-click the installer to launch it.
- Follow on-screen instructions to install the software.
- As soon as you press Finish, you can use the app.
- Select Everything or pick individual folders which you want the files to be recovered from.
- Press Next.
- At the bottom, enable Deep scan and pick which Disks you want to be scanned.
- Press Scan and wait till it is complete.
- You can now pick which folders/files to recover - don't forget you also have the option to search by the file name!
- Press Recover to retrieve your files.
- No More Ransom Project
- Free Ransomware Decryption Tools from Emsisoft
From our report of Jun 2022 · not reviewed since
Other tips
There are two basic ways of protecting yourself against ransomware attacks effectively - employing powerful anti-malware and having it on at all times and backing your files on a separate medium.
While the system must be remediated in order to be usable again, file recovery completely negates the need to contact the attackers and pay them money.
Otherwise, you may experience Blue Screens, program errors, crashes, and similar stability issues after malware removal completion.
Reporting the incident to your local authorities dealing with cybercrime can be a great help with catching criminals behind the attack. Contact your local branch with as many details as possible - here are a few links that could be useful to you:
You should contact the local police department or communications center if your country is not listed above.
- USA - Internet Crime Complaint Center IC3
- United Kingdom - ActionFraud
- Canada - Canadian Anti-Fraud Centre
- Australia - ScamWatch
- New Zealand - ConsumerProtection
- Germany - Polizei
- France - Ministère de l'Intérieur
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 .gachimuchi 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.
Access your website securely from any location
When you work on the domain, site, blog, or different project that requires constant management, content creation, or coding, you may need to connect to the server and content management service more often. The best solution for creating a tighter network could be a dedicated/fixed IP address.
If you make your IP address static and set to your device, you can connect to the CMS from any location and do not create any additional issues for the server or network manager that needs to monitor connections and activities. VPN software providers like can help you with such settings and offer the option to control the online reputation and manage projects easily from any part of the world.
Recover files after data-affecting malware attacks
While much of the data can be accidentally deleted due to various reasons, malware is one of the main culprits that can cause loss of pictures, documents, videos, and other important files.
More serious malware infections lead to significant data loss when your documents, system files, and images get encrypted. In particular, ransomware is is a type of malware that focuses on such functions, so your files become useless without an ability to access them.
Even though there is little to no possibility to recover after file-locking threats, some applications have features for data recovery in the system. In some cases, can also help to recover at least some portion of your data after data-locking virus infection or general cyber infection.
Questions about Gachimuchi virus
How do I open .gachimuchi files?
You cannot open them by renaming or with another program, because the content of files ending in .gachimuchi 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 Gachimuchi virus decryptor?
We last checked on 6 October 2026, and for Gachimuchi 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 "Gachimuchi 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.
Are ransomware recovery services legitimate?
Some are, but read the offer carefully. Genuine data-recovery firms recover deleted originals from disks or rebuild damaged files, and they say so. Others promise to "decrypt any ransomware" for a fixed price, which is impossible without the key; they quietly pay the attackers and keep a margin, sometimes without telling the victim.
Be especially careful with services that contact you after you post about the attack online. Ask for references, a written method and a no-result-no-fee clause, and check the free tools on No More Ransom first.
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.
How did Gachimuchi virus get on my computer?
The way Gachimuchi 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 .gachimuchi 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 Gachimuchi virus steal my files or passwords?
We do not know yet. Nothing published so far shows data theft by Gachimuchi virus, but the only confirmed sign is files that end in .gachimuchi 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 Gachimuchi 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 HOW_TO_DECRYPT#.txt tell me about the ransomware?
Quite a lot. The file name HOW_TO_DECRYPT#.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.
My files got .gachimuchi overnight. What happened?
Ransomware often runs at night or when the PC is idle, so the encryption finishes before anyone notices. It usually entered earlier through a cracked program, a fake installer, an e-mail attachment or remote desktop with a weak password.
The .gachimuchi extension marks every file it reached. Start by disconnecting the PC from the network, then identify the family from the ransom note and one encrypted file, check for a decryptor, and look for copies in backups and OneDrive before you consider anything else.
Will Fortect remove Gachimuchi 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 Gachimuchi 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
- Insurance Journal: FBI Chief Wray Warns Cyber-Attacked Firms Not to Pay Ransoms (read October 6, 2026)
- CISA: StopRansomware (read October 6, 2026)
- No More Ransom (read October 6, 2026)
- FTC: How to recognize, remove and avoid malware (read October 6, 2026)
- Microsoft Learn: Microsoft Defender Offline (read October 6, 2026)