GOTHAM Ransomware Decryptor
GOTHAM is a ransomware threat that stems from the GlobeImposter family. This strain is crafted to encrypt a victim’s files and lock them behind the .GOTHAM extension. Once the encryption stage is completed, the malware leaves a ransom instruction file named how_to_back_files.html. Inside, victims are directed to purchase Bitcoin and contact the attackers for file recovery. As part of their pressure tactics, the criminals allow one small file to be decrypted for free as “proof of service.” They also stress that victims must avoid renaming files or using unverified decryption tools.
Visual changes on infected machines
When GOTHAM runs on a system, it alters files so that each one ends with .GOTHAM. For example, project.docx becomes project.docx.GOTHAM. Alongside these changes, an HTML ransom message appears in the system, usually titled how_to_back_files.html. This note not only explains the demand but also provides step-by-step instructions for buying cryptocurrency and communicating with the cybercriminals.
Removal versus data recovery
Clearing GOTHAM from a computer halts new files from being encrypted, but it does not restore the files already locked. To regain access to the affected content, one of the following must occur:
- A valid decryption key is acquired, either from the attackers or through a specialized decryptor.
- The victim restores data from safe backups or uncorrupted snapshots.
Pathways to data recovery: free, on-premise, and professional services
Free possibilities
Backups: If backups exist on secure, offline, or immutable storage, administrators can roll systems back after verifying their integrity. All backups should be scanned thoroughly before restoration.
Weak variants check: In rare cases, earlier or flawed versions of ransomware leave exploitable weaknesses. Victims can explore whether their encrypted files fall into this category, though this is uncommon.
Localized and on-premise recovery
Hypervisor snapshots: If hypervisors such as VMware ESXi still hold clean snapshots taken before infection, those can be restored. Administrators must first confirm that snapshots have not been tampered with or encrypted.
Brute-force or research approaches: Only feasible if a cryptographic vulnerability exists. This is resource-intensive and rarely effective against GlobeImposter-based threats.
Paid and vendor-assisted methods
Ransom payment: Strongly discouraged — even if payment is made, attackers may fail to send valid keys. Moreover, this finances further criminal activity.
Negotiation services: Professional negotiators sometimes step in to lower ransom demands, but their fees are high and success is never guaranteed.
Our professional GOTHAM Decryptor service:
- Victim ID mapping: Our decryptor leverages the personal ID found in the ransom note to pinpoint the exact encryption set.
- Cloud sandbox verification: Files are processed in an isolated environment, with every action tracked in a tamper-evident ledger.
- Free trial decryption: Victims receive one verified file decryption as confirmation of tool effectiveness.
- Premium analysis option: If the ransom note is unavailable, our advanced service attempts variant correlation to identify a recovery route.
- Requirements: The ransom note, encrypted samples, administrator-level access, and either internet connectivity or an offline transfer process.
- Caution: Always confirm vendor legitimacy with references, technical documentation, and successful test decrypts before proceeding.
Step-by-Step GOTHAM Decryptor User Guide
Assess the Infection
Verify that files end with .GOTHAM and check for the presence of how_to_back_files.html.
Secure the Environment
Disconnect infected devices immediately and confirm that no further encryption tasks are running.
Engage Our Specialists
Send sample encrypted files along with the ransom note for variant confirmation. We will run an analysis and share a recovery timeline.
Run Our Decryptor
Execute the GOTHAM Decryptor with administrator rights for best results. Internet connectivity is required to link with our secure servers.
Enter the Victim ID
Copy the unique ID from the ransom note into the tool for targeted decryption.
Start Decryption
Begin the process and allow the decryptor to restore files to their original, accessible state.
Early signs of compromise
Victims typically discover an infection when previously functional files fail to open. File names suddenly carry the .GOTHAM suffix, and ransom instructions appear either on the desktop or in affected folders. Infected systems may also display high CPU/disk activity during the encryption phase. Shadow copies are often deleted, and attempts to restore using built-in tools may fail.
Anatomy of the ransom note
The ransom message instructs victims to buy Bitcoin and contact the attackers via the following addresses:
The note warns against third-party tools and renaming files. Victims are told they can decrypt one file under 1 MB at no cost as a demonstration.
Extracted text highlights:
All your files have been encrypted!
Your personal ID
–
All your files have been encrypted due to a security problem with your PC.
If you want to restore them, write us to the e-mail:[email protected]
Additional Mailing Address e-mail:[email protected]
How to obtain Bitcoins
The easiest way to buy bitcoins is LocalBitcoins site. You have to register, click ‘Buy bitcoins’, and select the seller by payment method and price.
hxxps://localbitcoins.com/buy_bitcoins
Also you can find other places to buy Bitcoins and beginners guide here:
hxxp://www.coindesk.com/information/how-can-i-buy-bitcoins/
Free decryption as guarantee
Before paying you can send to us up to 1 files for free decryption. Please note that files must NOT contain valuable information and their total size must be less than 1Mb
Attention!
Do not rename encrypted files.
Do not try to decrypt your data using third party software, it may cause permanent data loss.
Decryption of your files with the help of third parties may cause increased price (they add their fee to our) or you can become a victim of a scam.
Encryption family and its challenges
Belonging to the GlobeImposter ransomware line, GOTHAM likely uses hybrid or symmetric encryption. Keys are controlled by the threat actors, making recovery without their cooperation nearly impossible. The malware’s removal does not decrypt files — it only prevents further damage.
Infection channels
Attackers deliver GOTHAM through a variety of methods, such as:
- Phishing emails carrying infected documents or macros.
- Software cracks and counterfeit installers.
- Drive-by downloads and malicious ads.
- Trojan loaders and backdoors.
- Occasionally, propagation across network shares or portable drives.
Security product detection names
Different antivirus engines flag GOTHAM under varying names, including:
- Avast: Other:Malware-gen [Trj]
- Combo Cleaner: Generic.Ransom.GlobeImposter.359DD48C
- ESET-NOD32: Win32/Filecoder.FV
- Kaspersky: Trojan-Ransom.Win32.Purgen.gc
- Microsoft: Ransom:Win32/Ergop.A
Indicators of Compromise (IOCs)
- File extension: .GOTHAM
- Ransom note: how_to_back_files.html
- Attacker emails: [email protected], [email protected]
- Text fragments to scan: “All your files have been encrypted!”, “Your personal ID”, LocalBitcoins references
Techniques, tactics, and procedures (TTPs)
Mapped to MITRE ATT&CK:
- Initial Access (T1566): Phishing with attachments.
- Execution (T1204): User-initiated execution of disguised software.
- Persistence (T1547): Registry keys or scheduled tasks.
- Privilege Escalation (T1548): Exploit or credential use.
- Defense Evasion (T1562): Disabling security tools and wiping shadow copies.
- Credential Access (T1003): Possible trojan pairing for credential theft.
- Lateral Movement (T1021): Spread via SMB or remote services.
- Exfiltration (T1041): Potential in GlobeImposter campaigns.
- Impact (T1486): File encryption and ransom demand.
Common utilities include generic loaders, trojans, password stealers, and tools to remove shadow copies.
Containment and urgent response steps
- Isolate compromised devices from networks.
- Preserve ransom notes and encrypted file samples unmodified.
- Collect volatile evidence like running processes, memory, and network data.
- Avoid renaming encrypted files or using unverified decryptors.
Long-term defense strategies
Security best practices against ransomware include:
- Enforce multi-factor authentication.
- Regularly patch firewalls, VPNs, and exposed services.
- Disable unused RDP or restrict with strict rules.
- Deploy immutable, air-gapped backups.
- Train staff to spot phishing attempts.
- Avoid pirated or unverified downloads.
- Implement endpoint detection and continuous threat hunting.
Victim Data Insights
Countries Affected
Sectors Targeted
Timeline of Incidents
Conclusion
GOTHAM employs the same core techniques seen in many ransomware families: encrypting files, demanding cryptocurrency, and leveraging fear to force payments. The priority actions are containment, preserving evidence, and carefully validating recovery options. Victims without functional backups may require a professional decryptor service, but ransom payments should be avoided unless all legal, ethical, and practical alternatives are exhausted.
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