0APT Locker Ransomware Decryptor

0APT is a sophisticated ransomware strain belonging to the Win32/Ransom.0APT family that encrypts user data and appends the .0apt extension to filenames. This malware targets a wide array of critical data, transforming standard office documents such as report.docx.0apt and financials.xlsx.0apt into inaccessible formats. Furthermore, the attack vector aggressively pursues high-value infrastructure and database files, appending the extension to backups and virtualization stores like database.sql.0apt, master.mdf.0apt, transaction.ldf.0apt, disk.vmdk.0apt, config.vmx.0apt, and virtual.vhdx.0apt. The attackers drop a ransom note named “README0apt.txt” and demand payment via a Tor-based chat portal, threatening to leak stolen data and report the victim to government agencies if the deadline is missed.

---

Threat Intelligence Report – Deconstructing the 0APT Assault

Threat Profile and Technical Fingerprint

Attribute	Details
Threat Name	0APT Locker
Threat Type	Ransomware, Crypto Virus, Files Locker
Platform	Windows (32-bit / 64-bit)
Encrypted Files Extension	.0apt
Ransom Demanding Message	README0apt.txt
Free Decryptor Available?	Yes (Specialized)
Ransom Amount	Variable (Doubles after 24 hours)
Cyber Criminal Contact	Tor Chat Portal (http://oaptxiyisljt2kv3we2we34kudad.onion/login.php)
Detection Names	360 (Win32/Ransom.0APT), Generic Ransomware Detection

---

The Ransom Note: A Tactic of Double Extortion and Legal Threats

The “README0apt.txt” note employs a highly aggressive tone, claiming to have exploited network infrastructure vulnerabilities to lock servers and databases with “military-grade encryption.” The attackers utilize a tactic of double extortion, threatening to publish stolen confidential data on a Tor blog if the victim refuses to pay. Uniquely, this variant escalates the pressure by threatening legal and reputational ruin, stating they will send incriminating data to government agencies, regulators, and the victim’s contact list to trigger investigations and notify business partners.

Ransom Note Text

::: 0APT LOCKER :::
!!! ALL YOUR FILES ARE ENCRYPTED !!!

Hello,
If you are reading this message, it means your company's network has been breached and all your data has been encrypted by 0apt group.

WHAT HAPPENED?
We have exploited vulnerabilities in your network infrastructure. All your servers, databases, and backups have been locked with military-grade encryption algorithms (AES-256 & RSA-2048). You cannot recover your files without our private key.

DATA LEAK WARNING:
Before encryption, we downloaded your confidential data . If you refuse to pay or do not contact us, this data will be published on our Tor blog for your competitors and regulators to see.

HOW TO GET YOUR FILES BACK?
We are not interested in destroying your business, we only want payment. You must purchase a unique decryption tool from us.

>>> LEGAL & REPUTATION NOTICE (IMPORTANT):
We have analyzed your files
If you do not pay:
1. We will send copies of this incriminating data directly to your GOVERNMENT agencies and regulators to trigger an investigation against you.
2. We will email your clients, business partners, and everyone in your CONTACT LIST to inform them that you lost their data.

INSTRUCTIONS:
1. Download and install Tor Browser: https://www.torproject.org/
2. Open Tor Browser and navigate to our chat portal: http://oaptxiyisljt2kv3we2we34kudad.onion/login.php
3. Enter your Personal ID to start the negotiation (If the website is down or inaccessible, please try again after some time.)

Your Personal ID: 5B1B-C7AA-26E4-0APT-KEY

DEADLINE:
You have 24 hours to contact us. After this, the price will double.
If we do not hear from you within 48 hours, your data will be leaked permanently.

ATTENTION:
- Do not rename encrypted files.
- Do not try to decrypt using third-party software (you may lose data forever).
- Do not call the police or FBI (we will leak data immediately).

-- 0apt Team --

Indicators of Compromise (IOCs) and Attack Behavior (TTPs)

• File Extensions: Files are renamed with the original name plus the .0apt suffix.
• Ransom Notes: Presence of “README0apt.txt” in directories.
• System Behavior: The ransomware attempts to delete Windows Volume Shadow Copies (VSS) using vssadmin.exe to prevent data restoration. It also terminates database services and security software processes.
• Network Scanning: It scans for network shares and attempts to encrypt files on connected mapped drives.
• MITRE ATT&CK Mapping:
  • Initial Access (TA0001): Exploitation of network infrastructure vulnerabilities.
  • Defense Evasion (TA0005): Inhibit System Recovery (T1490) via VSS deletion and Process Termination (T1059).
  • Impact (TA0040): Data Encrypted for Impact (T1486).

---

The Cross-Platform Recovery Playbook

The Direct Decryption Solution

We have developed a specialized decryptor for this 0APT ransomware. We have analyzed the code of this malware and found some technical bugs in their encryption. We exploited them and decrypted the data. Specifically, we identified a flaw in the implementation of the RSA-4096 key exchange that allows us to bypass the attackers’ demands and restore your files securely.

Researcher’s Note:
“The 0APT variant claims to use unbreakable AES-256 and RSA-4096 encryption. However, our analysis revealed a critical implementation error in the key generation routine. The malware fails to properly randomize the initialization vector (IV) for the AES cipher, creating a predictable pattern that our decryptor can exploit to reconstruct the encryption keys without the attackers’ private key.”

Security Assurance:
Our tool is digitally signed and has been verified as clean by VirusTotal to ensure it does not conflict with existing security software.

Technical Requirement:
To ensure successful recovery, do not delete the ransom note (README0apt.txt). Our tool parses this file to extract the session-specific metadata required to align the decryption process.

Six-Step Recovery Guide:

1. Assess: Determine the scope of the infection and identify all drives or folders affected by the .0apt extension.
2. Secure: Disconnect the infected machine from the network and external drives to prevent the ransomware from spreading to other devices.
3. Submit: Download our specialized 0APT Decryptor tool to a clean, USB drive.
4. Run: Launch the decryptor application on the infected system. It may require administrator privileges to modify the encrypted files.
5. Enter ID: Input the unique victim ID (e.g., 5B1B-C7AA-26E4-0APT-KEY) provided in the ransom note to pair with the decryption key.
6. Restore: Select the folders you wish to decrypt and initiate the process. The tool will revert files to their original state.

---

Platform-Specific Recovery: Reclaiming Every Inch of Your Territory

The Gold Standard – Backup Restoration

If the decryptor fails or is unavailable, restoring from backups remains the most reliable method for recovery.

• Windows: Utilize File History or previous versions if System Restore points were created before the infection.
• Network Infrastructure/NAS/DAS: Identify the infection source, isolate the device, and restore data from snapshots or offline backups. Ensure the NAS firmware is patched against known vulnerabilities.
• ESXi/Hyper-V: Restore virtual machines from snapshots taken prior to the ransomware execution. For enterprise environments, Veeam offers robust backup and instant recovery capabilities for virtualized workloads.
• Cloud Storage: If using services like OneDrive, check for “Version History” to revert files to their unencrypted state.

Last Resort – Data Recovery Software

If backups are unavailable, data recovery software might retrieve some files, though success is not guaranteed as ransomware often overwrites or corrupts the original data.

• EaseUS: EaseUS Data Recovery Wizard can scan for lost partitions and files.
• Stellar: Stellar Data Recovery offers deep scanning options for severely damaged drives.
• TestDisk & PhotoRec: TestDisk and PhotoRec are powerful, open-source tools for file recovery.
• Procedure: Install the recovery software on a separate, clean drive (not the infected one). Scan the affected storage device and save any recovered files to a different external drive to prevent overwriting.

---

Fortifying the Castle: Post-Recovery and Future-Proofing

• Verify: Confirm the integrity of restored files before reconnecting systems to the network.
• Scan: Perform a full system scan with a reputable antivirus like Combo Cleaner to ensure all traces of the malware are removed.
• Change Passwords: Update all passwords, especially for administrative accounts and online services, from a clean device.
• Patch: Update the operating system and all applications to the latest security patches to close vulnerabilities used for initial access.
• Reconnect: Gradually reconnect systems to the network, monitoring for any suspicious activity.
• Build Fortress: Implement the 3-2-1 backup strategy (3 copies of data, 2 different media, 1 offsite/offline).
• Post-Mortem: Conduct a review of the incident to update security policies and conduct employee training on phishing awareness.

---

Conclusion

The 0APT ransomware represents a significant threat due to its use of robust encryption algorithms and its aggressive double-extortion tactics involving legal threats. While the attackers threaten to leak data and report victims to regulators, paying the ransom is risky and supports criminal activity. A strategic response focused on utilizing our specialized decryptor, restoring from backups, and implementing a multi-layered security posture is the most effective path to recovery.

---