Get free scan and check if your device is infected.
Remove it nowTo use full-featured product, you have to purchase a license for Combo Cleaner. Seven days free trial available. Combo Cleaner is owned and operated by RCS LT, the parent company of PCRisk.com.
What is Herrco ransomware?
Cybercriminals behind Herrco ransomware target computers owned by commercial businesses (companies). Although, they may target computers owned by separate individuals as well. This ransomware blocks access to files by encrypting them and changes their filenames by appending the ".herrco" extension.
For example, Herrco renames a file named "1.jpg" to "1.jpg.herrco", "2.jpg" to "2.jpg.herrco", and so forth. Also, this ransomware creates the "How to decrypt files.txt" text file - a ransom note that contains instructions on how to contact the attackers and some other information.
Screenshot of a message encouraging users to pay a ransom to decrypt their compromised data:
Herrco ransom note overview
As stated in the "How to decrypt files.txt" text file, the only way to quickly and reliably regain access to files is to contact the attackers and follow the provided instructions. It is also stated that the price of data decryption depends on how fast victims will contact the attackers.
Victims are instructed to contact the attackers via the provided Tor website. They have to enter their ID (which can be found at the top of the ransom note) and email address on the provided website and then follow the instructions. Additionally, victims are offered free decryption of several files that do not contain any valuable information.
In the last paragraph of the ransom note, victims are warned not to try to decrypt files with third-party software because it may cause permanent data loss or the price of data decryption may become higher. In conclusion, "How to decrypt files.txt" instructs victims to use the provided Tor website to contact cybercriminals and then follow their instructions.
More information about ransomware
Typically, victims cannot decrypt files without the right decryption tools, and the attackers are the only ones who have them. Although, victims often do not receive any decryption tools even if they pay for them. Therefore, it is not recommended to pay any cybercriminals a ransom (even if they decrypt some files for free).
In most cases, the only free data recovery option is to restore it from a backup. However, it cannot be done if victims do not have their files backed up. Sometimes, it is possible to decrypt files with a free tool downloaded from the Internet. Unfortunately, there is no third-party tool that could decrypt files encrypted by Herrco.
Another important detail about ransomware is that it could be capable of causing further encryption - it may encrypt new files or infect computers connected to the same local network (encrypt files stored on those computers). For these reasons, it is strongly recommended to remove ransomware from infected machines as soon as possible.
Similarities with other ransomware variants
Most ransomware variants are designed to encrypt files and generate a ransom note (provide contact and payment information). Two key differences between ransomware attacks are the prices of decryption tools and cryptographic algorithms used to encrypt files. More ransomware examples are HORSEMONEY, WIZOZ, and STOLEN.
As mentioned in one of the previous paragraphs, most ransomware victims cannot recover their files without losing any money unless they have their files backed up. Therefore, it is strongly recommended always to have a data backup and store it on a remote server like Cloud or an unplugged storage device.
How did ransomware infect my computer?
Most cybercriminals use Trojans, emails, untrustworthy sources for downloading files and programs, software cracking tools, and fake software updaters to distribute malware. Trojans can cause damage only when they are already installed on computers. Once installed, certain Trojans can install their payload (install additional malware).
Malware gets installed via emails when recipients open malicious attachments or files downloaded via received website links. Usually, cybercriminals use email as a tool to trick recipients into opening malicious Microsoft Office documents, executable files (like EXE), archive files (like RAR, ZIP), JavaScript files, PDF documents.
Examples of unreliable sources to download files (and programs) are Peer-to-Peer networks (such as torrent clients, eMule, and so on), third-party downloaders, free file hosting websites, freeware download pages. Users infect computers when they download and open malicious files (usually, those files are disguised as legitimate, harmless files).
Software cracking tools are supposed to activate licensed software (illegally). However, not all cracking tools function as their users expect them to. Users unknowingly infect their computers when they use cracking tools that are bundled with malware (which is pretty common).
Fake software updaters can cause damage by installing malicious software instead of updates, fixes, or exploiting bugs, flaws of outdated software installed on a computer. In one way or the other, fake updaters do not update or fix any software. Usually, those updaters are distributed by disguising them as legitimate installers.
| Name | Herrco virus |
| Threat Type | Ransomware, Crypto Virus, Files locker |
| Encrypted Files Extension | .herrco |
| Ransom Demanding Message | How to decrypt files.txt |
| Cyber Criminal Contact | Tor website (link is provided in the ransom note) |
| Detection Names | Avast (Win32:Dh-A [Heur]), Combo Cleaner (Gen:Heur.Ransom.REntS.Gen.1), ESET-NOD32 (A Variant Of Win32/Filecoder.OHO), Kaspersky (HEUR:Trojan-Ransom.Win32.Generic), Microsoft (Ransom:Win32/GarrantDecrypt.PA!MTB), Full List Of Detections (VirusTotal) |
| Symptoms | Cannot 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. |
| Additional Information | Cybercriminals behind Herrco target companies |
| Distribution methods | Infected email attachments (macros), torrent websites, malicious ads. |
| Damage | All 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. |
| Malware Removal (Windows) |
To eliminate possible malware infections, scan your computer with legitimate antivirus software. Our security researchers recommend using Combo Cleaner. Download Combo CleanerTo use full-featured product, you have to purchase a license for Combo Cleaner. 7 days free trial available. Combo Cleaner is owned and operated by RCS LT, the parent company of PCRisk.com. |
How to protect yourself from ransomware infections?
It is strongly recommended not to open attachments or files in emails when they are not relevant and sent from unknown, suspicious addresses. It is important to mention that cybercriminals behind emails used to deliver malware pretend to be legitimate companies, organizations, or other entities.
Applications and files should be downloaded from official, legitimate pages. Files downloaded from unreliable sources could be designed to install unwanted and even malicious software. Third-party, unofficial tools should not be used to activate or update any software as well.
Quite often, third-party activation and updating tools are bundled with malware. Another reason not to use cracking tools is that it is illegal. The operating system and software installed on it have to be updated with tools or implemented functions provided by their official developers.
A computer should have a reputable antivirus or anti-spyware suite installed on it. It should be scanned for malware and other threats on a regular basis. It is also important to keep the installed security solution up to date. If your computer is already infected with Herrco, we recommend running a scan with Combo Cleaner Antivirus for Windows to automatically eliminate this ransomware.
Appearance of the "How to decrypt files.txt" file (GIF):
Text presented in Herrco ransomware's text file ("How to decrypt files.txt"):
Your personal identifier: ***********
All files on ***************************** network have been encrypted due to insufficient security.
The only way to quickly and reliably regain access to your files is to contact us.
The price depends on how fast you write to us.
In other cases, you risk losing your time and access to data. Usually time is much more valuable than money.In addition, we have ~170 gb of data from your network.
We can see your partners and if you don't get in contact, we will let them know that you were the source of the data leak.
We are aware of the strictness of the European data protection law (GPRD) and we are sure that you are not interested in publishing it.FAQ
Q: How to contact us
A: * Download Tor Browser - hxxps://www.torproject.org/
* Open link in Tor Browser hxxp://eghv5cpdsmuj5e6tpyjk5icgq642hqubildf6yrfnqlq3rmsqk2zanid.onion/contact
* Follow the instructions on the website.Q: What guarantees?
A: Before paying, we can decrypt several of your test files. Files should not contain valuable information.Q: Can I decrypt my data for free or through intermediaries?
A: Use third party programs and intermediaries at your own risk. Third party software may cause permanent data loss.
Decryption of your files with the help of third parties may cause increased price or you can become a victim of a scam.
Screenshot of Herrco's Tor website:
Screenshot of files encrypted by Herrco (".herrco" extension):
Herrco ransomware removal:
Instant automatic malware removal:
Manual threat removal might be a lengthy and complicated process that requires advanced IT skills. Combo Cleaner is a professional automatic malware removal tool that is recommended to get rid of malware. Download it by clicking the button below:
DOWNLOAD Combo CleanerBy downloading any software listed on this website you agree to our Privacy Policy and Terms of Use. To use full-featured product, you have to purchase a license for Combo Cleaner. 7 days free trial available. Combo Cleaner is owned and operated by RCS LT, the parent company of PCRisk.com.
Removal and file recovery procedure
If your files are encrypted with a new extension and a ransom note has appeared, you've been hit by ransomware. Don't pay. The procedure below works in order: contain the infection, identify the variant, remove the ransomware itself (so anything you restore doesn't get re-encrypted), and try to recover files using free decryption tools, Windows Volume Shadow Copies, or backups. Run a full system scan with Combo Cleaner to remove the infection - then move on to file recovery.
Common ransomware behaviors
VisibleEncrypts your files and renames them
The ransomware reads each file, encrypts the contents with the attacker's public key, and writes the encrypted bytes back to disk. Most variants also rename the file by appending a new extension - .net, .locked, .crypt, .lockbit, .djvu, etc. Without the matching private key, the encrypted files cannot be opened normally. Recovery depends on a free decryption tool, a recoverable Volume Shadow Copy, or a clean backup.
VisibleDrops a ransom note in every encrypted folder
A text or HTML file (usually named HOW_TO_DECRYPT.txt, README.txt, _readme.txt, or similar) is placed in every folder that contains encrypted files. The note explains the situation, lists a payment amount in cryptocurrency, gives a deadline, and provides a contact email or .onion site. Save the note - don't delete it. Its exact wording, the email address, and the bitcoin wallet are how you identify the variant in the next phase.
VisibleReplaces the desktop wallpaper
Many ransomware variants change the Windows wallpaper to a black or red image with the ransom message and instructions. The wallpaper is just a visual scare tactic - it doesn't add any actual capability and reverts to normal once the ransomware is removed. Photograph it before removal in case the contact details are useful for variant identification or for reporting to authorities.
HiddenDeletes Volume Shadow Copies
One of the first things modern ransomware does after launching is run vssadmin delete shadows /all /quiet to wipe Windows' built-in Volume Shadow Copies - the snapshots that Previous Versions and System Restore rely on. Some ransomware doesn't fully succeed (especially on systems where the user lacks full admin rights), leaving partial shadow copies recoverable. Phase 4 step 11 covers how to check what survived.
HiddenDisables Windows Defender and other security tools
Before encrypting, the ransomware tries to silence anything that could alert you or block it - Windows Defender real-time protection, third-party antivirus services, backup agents (Veeam, Acronis), and sometimes the Windows Event Log service. It often modifies Group Policy or registry keys to keep these off after reboot. Phase 3 step 9 explicitly turns Tamper Protection back on so the next ransomware attempt can't repeat the trick.
HiddenSpreads laterally to other PCs on the network
Network-aware ransomware (LockBit, Conti, BlackCat, Akira families) doesn't stop at the first machine. It scans for SMB shares, mapped drives, and other PCs on the same network, then encrypts whatever it can reach. On Windows domains, a single compromised user with admin rights can lead to all-domain encryption. This is why Phase 1 step 2 disconnects the network as the very first action - it stops the spread immediately.
HiddenSteals data before encrypting (double extortion)
Modern ransomware (LockBit, BlackCat / ALPHV, Akira, Cl0p, Royal) almost always exfiltrates data before encrypting. The attacker then runs a "double extortion" play: pay the ransom for decryption, plus pay again to prevent the stolen data from being leaked on the group's leak site. Paying the first ransom does not get the leaked data back - assume that anything the ransomware could read was uploaded. This is one more reason not to pay: the data is already out.
Don't pay the ransom
Paying the ransom does not guarantee you'll get your files back. Major ransomware response studies consistently show that a meaningful percentage of paying victims either receive a non-working decryptor, only partial decryption, or no decryptor at all. Beyond that:
- Paying confirms you as a willing target - re-attack rates within 12 months are high
- Several ransomware groups have been sanctioned (US OFAC, UK OFSI). Paying these groups may be illegal under sanctions law in your country
- The ransom funds the next attack - on you or someone else
- Modern ransomware almost always exfiltrates data first, so paying doesn't get the leaked data back. Assume anything the malware could read was uploaded
- Decryptors, even when they work, often leave files corrupted because the encryption itself was buggy or rushed
The path below tries every legal, free recovery option first. Pay only as an absolute last resort, after consulting a lawyer and your country's cyber crime authority.
Disconnect from the network and log out of cloud storage
Pull the Ethernet cable and turn off Wi-Fi on the affected PC. If multiple computers share the network, do the same on every machine you suspect could be affected, including any servers and NAS units.
Then sign out of cloud storage clients (OneDrive, Dropbox, Google Drive, iCloud) from their app settings. If you can, pause the sync. Some ransomware uses the running sync client to push encrypted versions over your clean cloud copies.
Modern ransomware spreads laterally across SMB shares, mapped drives, RDP, and reachable network neighbors. Disconnecting stops the spread the moment you do it. Logging out of cloud sync clients prevents the ransomware from encrypting the cloud copies of your files via the sync API.
Unplug external drives and USB storage
Safely eject any external drives, USB sticks, SD cards, and network-attached storage shares - then unplug them. If a drive was connected when the ransomware ran, the files on it may already be encrypted, but unplugging stops further damage.
Critically: don't reconnect any drive (including your most recent backup) to this PC until the ransomware is removed in Phase 3. Reconnecting an external backup to an actively-infected PC is the most common way that backup gets encrypted too.
Save the ransom note and a sample encrypted file
Copy the ransom note and one small encrypted file (under 1 MB) to a USB stick, or photograph the note with your phone. You'll need both for the variant identification step.
The ransom note is usually one of:
- A
.txtfile in every encrypted folder (typicallyHOW_TO_DECRYPT.txt,README.txt, or_readme.txt) - An
.htmlfile with the same purpose - A changed desktop wallpaper - photograph it
- A lock-screen interrupt that runs at startup - rarer
Don't delete the note. Variant identification depends on its exact wording, the contact email, and the bitcoin wallet address. The note is also evidence if you report to authorities.
Identify the variant with ID Ransomware
From a clean device (your phone is fine, or another PC that wasn't on the affected network), visit id-ransomware.malwarehunterteam.com. Upload the ransom note and the sample encrypted file. The site identifies the variant family and tells you whether a free decryptor exists.
ID Ransomware is run by the Malware Hunter Team. Files you upload are kept private - they're used for analysis, not published. If you're concerned about uploading data anyway, you can paste the contact email and bitcoin wallet from the note - those are often enough for identification.
The ransomware itself must be removed before any file recovery. If it's still active, anything you restore in Phase 4 gets re-encrypted within minutes.
Boot to Safe Mode with Networking and download the scanners
Safe Mode loads only the minimal Windows drivers, which prevents most ransomware from auto-running while you set up the scanners.
Windows 11: open , click Restart now next to Advanced startup. After the restart, click , then press 5 or F5.
Windows 10: click the Windows logo, hold Shift, click the Power icon and choose Restart. From the Choose-an-option screen, click , then press F5.
Once Safe Mode has loaded, turn Wi-Fi back on and download Combo Cleaner (used in step 8) and Microsoft Safety Scanner (used in step 9). Save both installers to your Desktop, then disconnect Wi-Fi again before scanning.
Run Microsoft Defender Offline
Reboot to normal Windows. Open . Select Microsoft Defender Antivirus (offline scan) and click Scan now. The PC restarts into a stripped-down environment and scans the disk before Windows fully loads.
Some ransomware variants drop bootkit components or kernel hooks that hide from any scanner running on the same Windows session that's already infected. A pre-boot offline scan sees the disk before the malware can load itself.
VB100 certified. Includes anti-trojan, registry/persistence scanning, and anti-spyware in one pass. The 7-day free trial is available.
Download Combo CleanerRun a full Combo Cleaner scan
Run the installer you downloaded in step 6 and start a full system scan (not the quick scan). Let it complete, review what it detected, and apply the recommended actions. Combo Cleaner quarantines the ransomware executable and the registry / scheduled-task entries that re-launch it on reboot.
Run Microsoft Safety Scanner and re-enable Defender
Run Microsoft Safety Scanner (MSERT.exe) as a second-opinion full scan. The binary expires every 10 days so the copy you downloaded has the latest signatures.
Once it finishes, open and confirm Real-time protection, Cloud-delivered protection, and Tamper Protection are all on. Many ransomware variants disable Defender during the attack - this is where you switch it back on so the next attempt can't repeat the trick.
Different scanning engines catch different threats. Running an additional Microsoft scan after Combo Cleaner is the most underused verification step in malware removal - and free.
Try the steps in order. The first decryptor that works ends the recovery process - no need to do all four.
Check the No More Ransom Project for a free decryptor
Visit nomoreransom.org and search the Decryption Tools list for the variant name returned by ID Ransomware. The project is run by Europol, the Dutch Police, and security vendors - everything listed is legitimate and free.
If a decryptor exists, download it onto a clean PC, copy it across, and follow its instructions exactly. Decryptors usually want you to point them at a sample encrypted file plus its known unencrypted version (sometimes any image you previously had a backup of works).
Free decryptors exist for parts of the STOP/Djvu, GandCrab, REvil, Avaddon, Conti and Hive families, among others. Most modern variants don't have public decryptors - if yours isn't listed, that's expected; move to the next step.
Try Windows Volume Shadow Copies
Windows automatically creates Volume Shadow Copies of files when System Restore points are made or scheduled backups run. Most ransomware tries to wipe these (vssadmin delete shadows /all /quiet), but the deletion sometimes fails partially - especially if the running user doesn't have full admin rights. When it does fail, snapshots survive that contain pre-encryption versions of your files.
First, check what's there. Open Command Prompt as Administrator and run:
vssadmin list shadows
If you see entries listed, shadow copies survived. To restore from them:
- Built-in: right-click any folder → Properties → Previous Versions tab. Pick a snapshot dated before the infection and restore.
- Better tool for browsing: install Shadow Explorer (free). It shows all snapshots as a normal file tree and lets you copy out only the files you want.
Shadow Copies recover the original files exactly, with no risk of decryption errors. If they survived, this is faster and cleaner than running a decryptor on the encrypted set.
Restore from cloud or external backup
If you have a backup that pre-dates the infection, this is the cleanest recovery available. Important precautions:
- Don't reconnect a backup drive until Phase 3 is complete. If the ransomware is still active, plugging in the backup encrypts it too.
- For cloud backups (OneDrive, Dropbox, Google Drive, iCloud), use the Version History feature to roll individual files back to pre-encryption versions.
- OneDrive specifically has a "Restore your OneDrive" feature: if it detected mass file changes, you can roll back the entire account up to 30 days. Sign in at OneDrive on the web, click the Settings gear, and choose Restore your OneDrive. Microsoft 365 subscribers also get ransomware detection alerts; non-subscribers get one free recovery.
- Verify the restored files open correctly before you delete the encrypted set. Test a few documents, photos, and any database / project files.
Try Recuva as a last-resort recovery
Recuva is a long shot, not a primary recovery tool. Most modern ransomware encrypts files in place - it reads the original, encrypts the data, and writes the encrypted bytes back to the same disk location. In that case, the original isn't deleted, just rewritten - and Recuva has nothing to find.
But for older or simpler variants that deleted originals before creating encrypted copies (rather than encrypting in place), Recuva can sometimes pull the originals from unallocated disk space. Worth trying as a last resort, especially before you use the disk much further.
If you try it:
- Stop using the disk as much as possible - every disk write reduces recovery odds
- Run Recuva from a USB stick, not from the affected disk
- Use Deep Scan mode (slower but the only mode worth running for this scenario)
Don't skip the steps above expecting Recuva to bail you out. It works in maybe 5-20% of cases, depending on the variant and how soon you try.
Report the attack to authorities
Even if your files aren't recovered, your report helps authorities track variants, attribute groups, and warn future victims. In some jurisdictions (especially the US and UK) early reporting can sometimes help recall a wired ransom payment via banking partners.
Save the report number - banks, insurers, and credit bureaus will ask for it. If you operate a business, you may also have legal disclosure obligations (GDPR in the EU, state breach laws in the US) that run on a 72-hour clock.
Plan 3-2-1 backups going forward
The single best defense against ransomware is a tested backup. Use the 3-2-1 rule:
- 3 copies of your data
- 2 different storage media (e.g., internal drive + external drive)
- 1 offline / air-gapped copy (an external drive that isn't always connected)
Recommended cadence:
- Daily: cloud sync (OneDrive, Dropbox, Google Drive) - convenient, but vulnerable if the ransomware reaches the sync folder. The Version History feature is what saves you
- Weekly: external drive that you connect briefly, then disconnect - the air-gap is what protects against ransomware
- Monthly: a second external drive stored off-site (different physical location) - protects against fire, theft, flood
Test the backup at least once. Open a few files from it, check sizes match, restore one to a different folder. An untested backup isn't a backup - it's a hope.
Patch the entry point and monitor for 30 days
Most reinfections happen via the same vector that worked the first time. Until you've patched the entry point, watch for:
- Unusual disk activity, unexpected file modifications, or unfamiliar processes in Task Manager
- Unexpected reboots or new accounts you didn't create
- Defender or your antivirus turning itself off again
Common entry vectors and what to do about each:
- Phishing email with a malicious attachment - review email filters and train yourself / staff to recognise the patterns - see pcrisk's Phishing/Scam reference
- Exposed RDP with weak passwords - disable Remote Desktop from if you don't need it. If you do, put it behind a VPN and require a long password plus MFA
- Unpatched VPN appliances or public-facing apps - check the vendor's advisories page and apply the latest firmware
- Cracked / pirated software - was the most common vector for STOP/Djvu in particular. Don't run software from torrent sites
Run a Combo Cleaner scan weekly for the first month. Update Windows, browsers, and applications aggressively.
Important: Removing a ransomware infection requires a full system scan, not a manual file delete. If you're not confident with the manual procedure, run an automated scan with Combo Cleaner and Windows Defender and stop there - that combination removes the vast majority of consumer ransomware variants. Then move to Phase 4 for file recovery, or to Phase 5 if your files are unrecoverable and you need to start fresh from a clean Windows install.
Share:
Facebook
X.com
LinkedIn
Copy Link
Tomas Meskauskas
Expert security researcher, professional malware analyst
I am passionate about computer security and technology. I have an experience of over 10 years working in various companies related to computer technical issue solving and Internet security. I have been working as an author and editor for pcrisk.com since 2010. Follow me on Twitter and LinkedIn to stay informed about the latest online security threats.
PCrisk security portal is brought by a company RCS LT.
Joined forces of security researchers help educate computer users about the latest online security threats. More information about the company RCS LT.
Our malware removal guides are free. However, if you want to support us you can send us a donation.
DonatePCrisk security portal is brought by a company RCS LT.
Joined forces of security researchers help educate computer users about the latest online security threats. More information about the company RCS LT.
Our malware removal guides are free. However, if you want to support us you can send us a donation.
Donate
▼ Show Discussion