PAHD ransomware is a new variant of STOP/DJVU virus
Contents
PAHD ransomware is a new file-encrypting virus from STOP/DJVU malware family. This computer threat uses RSA Salsa20 algorithm to lock files on victim’s computer, then marks them with .pahd extension. The new extension appears after the original file extension. For example, file originally called 1.jpg appears as 1.jpg.pahd after the encryption. During the computer scan, the ransomware also drops _readme.txt ransom note in every new affected folder. The note briefly informs that all victim’s files have been encrypted with the strongest algorithm and that the only way to decrypt these files is to purchase a PAHD decryption software from attackers for a specified ransom ($490 if paid within 3 days or $980 later). The note instructs to write to helpteam@mail.ch or helpmanager@airmail.cc for more details.
The main goal of the authors of this computer threat is to virtually extort the computer user by taking one’s files hostage. The attackers use advanced encryption algorithm that is typically used to secure military-grade secrets to make files inaccessible to the victim. According to the ransom note dropped in every folder, the only way of recovering files is paying a ransom. The criminals even suggest testing the decryption tool – they ask sending one small .pahd extension file to them, promising to reply with attached decrypted version of it. However, the ransomware operators won’t decrypt large file or one that contains important information, as they believe this could stop the victim from willing to pay the whole ransom at all.
Cybersecurity experts as well as FBI do not recommend paying ransoms to cybercriminals. Some of the reasons why you shouldn’t are:
- Paying the ransom does not, in all cases, guarantee file decryption. Cybercriminals are anonymous and can disappear any minute they want, especially after receiving your money.
- Consider the fact that paying the ransom might be illegal in your country.
- Do not contribute to the growing number of money the cybercriminals collect each year. This fuels up their operations, allows inviting more people to join in and expanding their reach.
- Variants of STOP/DJVU ransomware, including this one, are known to drop AZORULT Trojan on the system. It is a virus that operates silently and steals information from your computer, possibly to extort you later via email scam campaigns. Do you really want to transfer money for such knavish people?
Ransomware damage done to your computer: what has changed?
PAHD ransomware starts the attack by running a winupdate.exe process, which displays a fake Windows update prompt. This way, the ransomware tries to make up a reason for victim to justify the sudden system slowdown. The ransomware then bypasses security measures on a computer and starts scanning all folders for personal files, encrypting them with RSA Salsa20 algorithm. Once encrypted, files cannot be opened, modified (except of changing name, moving, etc.), but changes to actual file content cannot be done. However, the ransomware tends to encrypt only first 150KB of the file, therefore some media files (images, videos, music) might be repairable with minimal data loss. For more information, please refer to this guide.
The ransomware is designed to delete Volume Shadow Copies from the computer. This prevents the victim from restoring files for free using Windows System Restore Points. Next, the virus adds a list of domains to Windows HOSTS file, thus blocking Internet access to them. Attempts to access these websites directly or via search engines will result in DNS_PROBE_FINISHED_NXDOMAIN error. The domains added to the restricted list mostly publish various how-to articles on fixing computer errors, removing viruses, or simply sharing valuable insights on how to protect the computer from various threats. All of this is made to cause as much stress to the victim as possible, forcing one to start considering paying the ransom to take things back to normal.
The malware also installs AZORULT Trojan on the system. This virus can be used as a Remote Access Trojan (RAT) to remotely perform actions on victim’s computer. The list of its functionalities is lengthy, for example, it can be used to view or delete files on victim’s computer, also download something from external resources (such as more malware), collect Steam, Telegram login credentials, cryptocurrency wallets, browser cookies, saved passwords, browsing history and more. Collected information will be sent to criminals’ Command&Control server.
Needless to say, we strongly recommend you to take actions to secure your computer as soon as possible and prevent further damage. Remove PAHD ransomware virus and other threats using free instructions provided below this article. For virus removal, consider using a robust virus removal software. We strongly recommend using RESTORO to repair virus damage on the system.
Scan your system for FREE to detect security, hardware and stability issues. You can use the scan results and try to remove threats manually, or you can choose to get the full version of software to fix detected issues and repair virus damage to Windows OS system files automatically. Includes Avira spyware/malware detection & removal engine.
Ransomware Summary
| Name | PAHD Ransomware Virus |
| Type | Ransomware; Crypto-malware; Virtual Extortion Virus |
| Family | STOP/DJVU |
| Encryption type | RSA Salsa20 |
| Previous versions | DARJ DAZX, TYWD, TYCX, TYOS, TYPO, JYWD (find full list here) |
| Version | 301st |
| Extension | .pahd |
| Damage | The described ransomware uses RSA Salsa20 to encrypt files on victim’s computer. Consequently, affected files become inaccessible. The virus marks encrypted files by adding a new extension. The ransomware deletes VSS and modifies Windows HOSTS file by adding a list of blocked Internet domains. |
| Ransom note | _readme.txt |
| Ransom demand | $490-$980 in Bitcoin |
| Distribution | The ransomware hides in illegal torrent downloads, cracked software, key generators or KMSPico. |
| Detection names | Trojan:Win32/Glupteba (Microsoft), Glupteba.Backdoor.Bruteforce.DDS (Malwarebytes), TR/AD.InstaBot.bfsbw (Avira), HEUR:Exploit.Win32.Shellcode.gen (Kaspersky), Trojan.GenericKD.36669904 (B)(Emsisoft), W32.Trojan.Gen (Webroot) see all detection name variations on VirusTotal |
| Removal | Use a malware removal program to delete the ransomware and associated threats from your PC. Afterward, we strongly recommend scanning with RESTORO to repair virus damage on Windows OS files. |
Common ransomware distribution techniques to be aware of
Ransomware-type threats are distributed in common malware distribution ways. To be particular, STOP/DJVU variants such as PAHD virus can be found in illegal online torrents mainly. These include torrents that promise paid software or game versions for free. These downloads typically include cracks or keygens. For Office programs, malicious KMSPico versions may be used. However, opening such file can lead to disastrous consequences, such as losing all of your files in a couple of minutes, private data loss and more.
What is even worse is that most users get alerted by Windows or third-party security programs about a potentially malicious download, however, many users proceed to open such files, hoping to get desired software for free. The problem is that many users believe antivirus’ alerts regarding software cracks are mostly false-alarms and there is nothing to be afraid of; unfortunately, in the majority of cases, this isn’t true. Even if it seems that nothing happened after opening freshly downloaded file, you can get infected with silent malware that opens specific ports on your computer or starts using your computer’s resources for cryptocurrency mining.
We strongly recommend downloading software from trusted and legitimate sources only. This is the only way to avoid malware-injected software versions. Besides, typical software license prices are always lower than hefty ransom amounts asked by criminals.
Another popular malware distribution technique used by attackers is email spam. The attackers compose convincing email messages, usually stating that there is some kind of important information that needs to be reviewed by the recipient. The sender also pretends to be a colleague or someone from well-known company. The message urges to open the attached invoice/missing payment/document and replying as soon as possible. However, no matter the file format of attached file, it can contain a malicious script that downloads the malicious payload and executes it on your computer. It can be hard to identify an actually deceptive email message nowadays, especially when cybercriminals use email spoofing technique. You can learn more about this technique here. Our general advice is to only open emails from people you know and trust, or from someone you actually waited to write you. Do not let your curiosity take over when opening completely unexpected emails.
Victims of STOP/DJVU virus’ variants should be careful because other ransomware strain operators are leveraging the popularity of this virus’ and distributing fake decryptors hiding other malware. Therefore, an attempt to download STOP/DJVU decryption tool from suspicious online source can result in double ransomware encryption. One of malware strains that’s known for usage of this distribution technique is ZORAB.
Remove PAHD ransomware virus and decrypt or repair your files
Use the guide provided below to remove PAHD ransomware virus from your computer for good. Make sure you follow the provided steps carefully. Additionally, we recommend you to repair virus damage using software like RESTORO. In case you have any questions, do not hesitate and leave them in comments section below.
After successful PAHD virus removal, we recommend you to take the following actions:
- Report Internet crime incident to a respective authority in your country. We have provided some references below this guide.
- Use data backups to restore at least part of encrypted data.
- Follow the given guidelines on how to decrypt or repair files affected by STOP/DJVU versions.
- Consider changing all of your passwords (especially for accounts saved in browser) due to the Azorult’s activity.
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Our team recommends a two-step rescue plan to remove ransomware and other remaining malware from your computer, plus repair caused virus damage to the system:
STEP 1. REMOVE AUTOMATICALLY WITH ROBUST ANTIVIRUS
STEP 2. REPAIR VIRUS DAMAGE TO YOUR COMPUTER
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PAHD ransomware virus Removal Guidelines
Method 1. Enter Safe Mode with Networking
Step 1. Start Windows in Safe Mode with Networking
Before you try to remove PAHD ransomware virus virus, you must start your computer in Safe Mode with Networking. Below, we provide the easiest ways to boot PC in the said mode, but you can find additional ones in this in-depth tutorial on our website – How to Start Windows in Safe Mode. Also, if you prefer a video version of the tutorial, check our guide How to Start Windows in Safe Mode on Youtube.
Instructions for Windows XP/Vista/7 users
- First of all, turn off your PC. Then press the Power button to start it again and instantly start pressing F8 button on your keyboard repeatedly in 1-second intervals. This launches the Advanced Boot Options menu.
- Use arrow keys on the keyboard to navigate down to Safe Mode with Networking option and press Enter.
Instructions for Windows 8/8.1/10/11 users
- Open Windows Start menu, then press down the Power button. On your keyboard, press down and hold the Shift key, and then select Restart option.
- This will take you to Windows Troubleshoot screen. Choose Troubleshoot > Advanced Options > Startup Settings > Restart. Tip: If you can't find Startup Settings, click See more recovery options.
- In Startup Settings, press the right key between F1-F9 to enter Safe Mode with Networking. In this case, it is the F5 key.
Step 2. Remove files associated with the virus
Now, you can search for and remove PAHD ransomware virus files. It is very hard to identify files and registry keys that belong to the ransomware virus, Besides, malware creators tend to rename and change them repeatedly. Therefore, the easiest way to uninstall such type of a computer virus is to use a reliable security program such as INTEGO Antivirus. For virus damage repair, consider using RESTORO.
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Method 2. Use System Restore
In order to use System Restore, you must have a system restore point, created either manually or automatically.
Step 1. Boot Windows in Safe Mode with Command Prompt
Instructions for Windows XP/Vista/7 users
- Shut down your PC. Start it again by pressing the Power button and instantly start pressing F8 button on your keyboard repeatedly in 1-second intervals. You will see Advanced Boot Options menu.
- Using arrow keys on the keyboard, navigate down to Safe Mode with Command Prompt option and press Enter.
Instructions for Windows 8/8.1/10/11 users
- Launch Windows Start menu, then click the Power button. On your keyboard, press down and hold the Shift key, and then choose Restart option with the mouse cursor.
- This will take you to Windows Troubleshoot screen. Choose Troubleshoot > Advanced Options > Startup Settings > Restart. Tip: If you can't find Startup Settings, click See more recovery options.
- In Startup Settings, press the right key between F1-F9 to enter Safe Mode with Command Prompt. In this case, press F6 key.
Step 2. Start System Restore process
- Wait until system loads and command prompt shows up.
- Type cd restore and press Enter, then type rstrui.exe and press Enter. Or you can just type %systemroot%system32restorerstrui.exe in command prompt and hit Enter.
- This launches System Restore window. Click Next and then choose a System Restore point created in the past. Choose one that was created before ransomware infection.
- Click Yes to begin the system restoration process.
After restoring the system, we recommend scanning the system with antivirus or anti-malware software. In most cases, there won't be any malware remains, but it never hurts to double-check. In addition, we highly recommend checking ransomware prevention guidelines provided by our experts in order to protect your PC against similar viruses in the future.
Alternative software recommendations
Malwarebytes Anti-Malware
Removing spyware and malware is one step towards cybersecurity. To protect yourself against ever-evolving threats, we strongly recommend purchasing a Premium version of Malwarebytes Anti-Malware, which provides security based on artificial intelligence and machine learning. Includes ransomware protection. See pricing options and protect yourself now.
System Mechanic Ultimate Defense
If you're looking for an all-in-one system maintenance suite that has 7 core components providing powerful real-time protection, on-demand malware removal, system optimization, data recovery, password manager, online privacy protection and secure driver wiping technology. Therefore, due to its wide-range of capabilities, System Mechanic Ultimate Defense deserves Geek's Advice approval. Get it now for 50% off. You may also be interested in its full review.
Disclaimer. This site includes affiliate links. We may earn a small commission by recommending certain products, at no additional cost for you. We only choose quality software and services to recommend.
Decrypt PAHD files
Fix and open large PAHD files easily:
It is reported that STOP/DJVU ransomware versions encrypt only the beginning 150 KB of each file to ensure that the virus manages to affect all files on the system. In some cases, the malicious program might skip some files at all. That said, we recommend testing this method on several big (>1GB) files first.
- Create a copy of encrypted file to a separate folder using Copy > Paste commands.
- Now, right-click the created copy and choose Rename. Select the PAHD extension and delete it. Press Enter to save changes.
- In the prompt asking whether you want to make the changes as file might become unusable, click OK.
- Try opening the file.
STOP/DJVU decryption tool usage guide
STOP/DJVU ransomware versions are grouped into old and new variants. PAHD ransomware virus is considered the new STOP/DJVU variant, just like DARJ DAZX, TYWD, TYCX, TYOS, TYPO, JYWD (find full list here). This means full data decryption is now possible only if you have been affected by offline encryption key. To decrypt your files, you will have to download Emsisoft Decryptor for STOP DJVU, a tool created and maintained by a genius security researcher Michael Gillespie.
Note! Please do not spam the security researcher with questions whether he can recover your files encrypted with online key - it is not possible.
In order to test the tool and see if it can decrypt PAHD files, follow the given tutorial.
- Download the decryption tool from Emsisoft.
- Click the little arrow next to your download and choose Show in Folder.
- Now, right-click the file and choose Run as Administrator. If asked, enter administrator's password.
- In UAC window, click Yes.
- Click Yes to agree to software terms in both windows.
- The tool will automatically include C:// disk as a location to decrypt. The file recovery tool will prepopulate the locations to scan, including connected data storage drives or network drives. Click Add folder if you wish to add additional locations.
In Options tab, you can choose to keep encrypted file copies. We recommend leaving this option selected, especially if you do not know if the decryption tool will work. - Click Decrypt to start restoring PAHD files. You will see the progress in the Results tab. Here, you can see messages from the tool, such as whether the decryption procedure is successful, or you need to wait for an update.
You might also be informed that online key was used to encrypt your files. In such case, the decryption tool won't work for you, and the only way to recover your files is to use a data backup.
Meanings of decryptor's messages
The PAHD decryption tool might display several different messages after failed attempt to restore your files. You might receive one of the following messages:
Error: Unable to decrypt file with ID: [example ID]
This message typically means that there is no corresponding decryption key in the decryptor's database.
No key for New Variant online ID: [example ID]
Notice: this ID appears to be an online ID, decryption is impossible
This message informs that your files were encrypted with online key, meaning no one else has the same encryption/decryption key pair, therefore data recovery without paying the criminals is impossible.
Result: No key for new variant offline ID: [example ID]
This ID appears to be an offline ID. Decryption may be possible in the future.
If you were informed that an offline key was used, but files could not be restored, it means that the offline decryption key isn't available yet. However, receiving this message is extremely good news, meaning that it might be possible to restore your PAHD extension files in the future. It can take a few months until the decryption key gets found and uploaded to the decryptor. We recommend you to follow updates regarding the decryptable DJVU versions here. We strongly recommend backing up your encrypted data and waiting.
Report Internet crime to legal departments
Victims of PAHD ransomware virus should report the Internet crime incident to the official government fraud and scam website according to their country:
- In the United States, go to the On Guard Online website.
- In Australia, go to the SCAMwatch website.
- In Germany, go to the Bundesamt für Sicherheit in der Informationstechnik website.
- In Ireland, go to the An Garda Síochána website.
- In New Zealand, go to the Consumer Affairs Scams website.
- In the United Kingdom, go to the Action Fraud website.
- In Canada, go to the Canadian Anti-Fraud Centre.
- In India, go to Indian National Cybercrime Reporting Portal.
- In France, go to the Agence nationale de la sécurité des systèmes d’information.
If you can't find an authority corresponding to your location on this list, we recommend using any search engine to look up "[your country name] report cyber crime". This should lead you to the right authority website. We also recommend staying away from third-party crime report services that are often paid. It costs nothing to report Internet crime to official authorities.
Another recommendation is to contact your country's or region’s federal police or communications authority.
Frequently Asked Questions
You can only open PAHD files if you have the decryption key, or if you were affected by offline encryption type.
To figure out whether you were affected by offline encryption, please go to C:/SystemID/PersonalID.txt and see if the string inside of it ends in t1. You can also try using Emsisoft Decryptor for STOP/DJVU.
Please follow the guidances provided by the official PAHD decryption tools and believe what they say. If they say it is impossible to decrypt, it really is so. There is no magic tool or human capable of decrypting your files hiding somewhere. Encryption is a technique created to be nearly impossible to decrypt without a special private key (held by the criminals).
We advise scanning with anti-virus, anti-malware, malware removal tools or software like RESTORO to eliminate virus damage on the system. If you do not trust using a single tool, try running one after another. However, we do not recommend keeping several security programs on a computer at once as they can interfere with each other's work.
Beware of fake PAHD decryption tools circulating around the web. Cyber criminals are uploading them to various shady websites, also might be promoting them via suspicious Youtube videos. These programs can infect your computer even more heavily (Trojans, miners, etc.). We suggest being extremely cautious around the web. If there will be an official STOP/DJVU decryption tool available, it will be widely discussed in public media.
Norbert Webb is the head of Geek’s Advice team. He is the chief editor of the website who controls the quality of content published. The man also loves reading cybersecurity news, testing new software and sharing his insights on them. Norbert says that following his passion for information technology was one of the best decisions he has ever made. “I don’t feel like working while I’m doing something I love.” However, the geek has other interests, such as snowboarding and traveling.
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