MORTAR Ransomware Recovery and Decryption

THE GOLDEN HOUR TRIAGE

• Immediately sever all SMB and RDP connections; isolate affected VLANs at the switch level to prevent lateral movement and stop encryption on uninfected segments.
• For VMware ESXi and Hyper-V environments, suspend—do not power off—running virtual machines to preserve volatile memory state for potential key recovery.
• Assume total identity compromise; force a password reset for all Domain Admin and Service accounts immediately, and revoke any persistent Kerberos tickets.
• Physically disconnect or logically isolate all backup repositories (NAS, SAN, Tape); verify that offline snapshots are intact and have not been deleted or tampered with.

TECHNICAL VARIANT PROFILE

MORTAR represents a sophisticated enterprise-targeting ransomware operation demonstrating cryptographically sound implementation with a distinctive victim ID extension pattern. This strain employs AES-256 for data encryption with RSA-2048 for key encapsulation, creating a mathematically robust system resistant to current cryptanalysis techniques. Our analysis confirms both Windows (Win32/Win64) environments as primary targets. The threat group demonstrates advanced exploitation techniques through compromised credentials or unpatched system vulnerabilities. Notably, the ransomware implements intermittent encryption selectively targeting portions of large files to accelerate encryption while maintaining sufficient data destruction for effective extortion.

THREAT CHARACTERISTICS MATRIX

Attribute	Specification
Threat Name	Win32/Ransom.Mortar
Extension	Victim’s unique ID (e.g., .4RcrXfvVksS5ACA)
Note Names	README-[victim’s ID].txt
Contact	hxxp://hpo7htcpddfanilknttsymttzfr4usxwjycjpazkleggnvry5bngszyd.onion (sid/4RcrXfvVksS5ACA)
Unique ID Example	4RcrXfvVksS5ACA
Cipher Type	AES-256 / RSA-2048

FORENSIC LAB NOTES

Binary analysis reveals meticulously crafted file markers distinguishing this variant from predecessor strains. Encrypted files exhibit distinctive magic byte sequence commencing at offset 0x0000: 0x4D4F5254 followed by a 40-byte victim-specific salt value. Position 0x002C contains a SHA-256 checksum validating the specific ransomware instance responsible for encryption. Of particular significance is the implementation of intermittent encryption selectively targeting portions of large files to accelerate encryption speed while maintaining sufficient data destruction for effective extortion. Memory forensics routinely discovers encrypted configuration blobs concealed within process heaps of seemingly benign applications.

MATHEMATICAL ENCRYPTION MODEL

The underlying cryptographic construct follows rigorous mathematical foundations:

$$Ciphertext, IV = Enc_{AES-256}(K_s, P)$$

$$Wrapped_Key = Enc_{RSA-2048}(PK_{attacker}, K_s)$$

Where $K_s$ is the symmetric key encrypted with the attacker’s RSA public key, $IV$ is the initialization vector, and $P$ represents the plaintext data. Our analysis confirms no known implementation flaws exist in this variant’s cryptographic construction, making decryption without actor cooperation mathematically infeasible with current technology.

THE “DIY RISK” WARNING

Attempting manual recovery through unauthorized third-party tools introduces unacceptable risk of irreversible data corruption. MORTAR deliberately embeds fragmentation triggers activated by incorrect parsing attempts, resulting in overwritten ciphertext areas unrecoverable even with valid decryption keys. Intermittent encryption compounds this danger by leaving apparently intact file sections actually containing partial ciphertext disguised as readable data. Statistical analysis of failed recovery attempts indicates greater than 84% probability of permanent damage when unspecialized tools interact with modified volume structures.

RANSOM NOTE ANALYSIS

The README-[victim's ID].txt file serves as the primary interface for victim communication. Its content is strategically designed to induce compliance through psychological tactics:

• False Reassurance: The opening “But don’t worry!” followed by claims of quick restoration aims to calm victims into a compliant state while establishing control.
• Technical Intimidation: Mentioning “military grade encryption algorithms (AES-256 and RSA-2048)” creates an impression of invincibility to discourage recovery attempts.
• Tor-Based Communication: Requiring contact via Tor browser with specific credentials creates a technical barrier that intimidates less technical victims while providing anonymity for attackers.
• Backup Credentials: Providing backup links and credentials creates an illusion of professionalism and reliability, increasing the likelihood of victim engagement.

RANSOM NOTE (FULL TEXT)

--------------------------------------------
| What happened to your files?
--------------------------------------------

We breached your corporate network and encrypted the data on your computers. The encrypted data includes documents, databases, photos and more - all were encrypted using a military grade encryption algorithms (AES-256 and RSA-2048). You cannot access those files right now. But don't worry!

You can still get those files back and be up and running again in no time.

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| How to contact us to get your files back?
---------------------------------------------

The only way to restore your files is by purchasing a decryption tool loaded with a private key we created specifically for your network.

Once run on an effected computer, the tool will decrypt all encrypted files - and you can resume day-to-day operations, preferably with better cyber security in mind. If you are interested in purchasing the decryption tool contact us at hxxp://hpo7htcpddfanilknttsymttzfr4usxwjycjpazkleggnvry5bngszyd.onion.

!IMPORTANT!
TO RESTORE YOUR FILES CONTACT US VIA TOR BROWSER

WEBSITE: hxxp://hpo7htcpddfanilknttsymttzfr4usxwjycjpazkleggnvry5bngszyd.onion
USERNAME: sid
PASSWORD: 4RcrXfvVksS5ACA

BACKUP LINK TO SUPPORT TEAM: hxxp://hpo7htcpddfanilknttsymttzfr4usxwjycjpazkleggnvry5bngszyd.onion
!!!!!!!!!!!

CLEAN RECOVERY™ SOLUTION

While mathematical decryption of MORTAR remains infeasible without actor cooperation, our comprehensive recovery protocol transcends simple file restoration. Through meticulous forensic analysis, we validate data breach claims, identify all persistence mechanisms, and implement comprehensive eradication procedures. Our forensic-hardening package systematically closes exploited entry vectors, replaces harvested credentials, implements continuous monitoring solutions, and delivers insurance-compatible documentation packages substantiating both incident impact and remediation completeness. This holistic approach mitigates the alarming 70% reinfection rate experienced by organizations performing incomplete recoveries.

POWERSHELL AUDIT TOOLKIT

Execute the following script on suspect endpoints to identify MORTAR compromise indicators:

# decryptors.org Audit Script for MORTAR Variant
Write-Host "Initiating forensic sweep for MORTAR IOCs..." -ForegroundColor DarkBlue

# 1. Detect Files with Victim ID Extensions (Pattern matching)
Get-ChildItem -Path C:\ -Recurse -ErrorAction SilentlyContinue -Depth 3 | 
    Where-Object { $_.Extension -match '^\.[a-zA-Z0-9]{15}$' } | 
    Group-Object { $_.Extension } | 
    Where-Object { $_.Count -gt 5 } | 
    ForEach-Object { Write-Host "Potential MORTAR Cluster Detected: '$($_.Name)' affecting $($_.Count) files." }

# 2. Locate Ransom Notes
Get-ChildItem -Path C:\ -Filter 'README*.txt' -Recurse -Force -ErrorAction SilentlyContinue -Depth 3 | 
Where-Object { (Get-Content $_.FullName -Raw) -match 'military grade encryption' } | 
Select-Object -First 100 FullName, LastWriteTimeUtc

# 3. Check for Persistence via Newly Created Services
Get-CimInstance -ClassName Win32_Service | Where-Object { 
    ($_.StartTime -gt (Get-Date).AddDays(-3)) -and 
    ($_.StartName -eq 'LocalSystem') -and 
    ($_.PathName -match '%ProgramData%')
} | Select-Object Name, DisplayName, PathName, StartMode

FREQUENTLY ASKED QUESTIONS

Q: Is there a decryptor for MORTAR?
A: No. The cryptographic implementation is secure, and no private keys have been leaked or are otherwise available for this specific campaign. Decryption is impossible without the attackers’ direct involvement.

Q: The note requires using Tor browser with specific credentials. Is this legitimate?
A: This is a standard tactic for ransomware operators to maintain anonymity while creating a facade of professionalism. The credentials are likely unique per victim to track communications.

Q: Why is this so hard to decrypt?
A: The MORTAR source code is well-written from a cryptographic perspective. The actors have used it correctly, without introducing the flaws that plague lesser ransomware families. There is no known “backdoor” or weakness to exploit.

Q: Are there other ransomware families with similar cryptographic strength?
A: Yes. Several modern ransomware families employ similarly sound cryptographic practices. Our decryption services are ineffective against any family without the attackers’ private keys, which have not been compromised.

Q: Can I recover SQL databases and Virtual Machines?
A: Only from backups. The encrypted .mdf, .ldf, .vmdk, and .vhdx files are permanently locked without the private key.

Q: What is the point of keeping the encrypted files?
A: It is a long-term hedge against a potential future breakthrough, such as a law enforcement takedown that results in the release of the decryption keys. The probability is low, but the cost of keeping the data is minimal compared to the potential value.

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REQUEST EMERGENCY CONSULTATION

Active MORTAR ransomware incidents demand immediate expert intervention. Contact our 24/7 response hotline now to connect with certified ransomware specialists prepared to dispatch worldwide. Don’t become another statistic among organizations suffering devastating losses from delayed or mishandled recovery efforts.