Skip to content
Cyber Threat
CTI Academy Sponsor CTI Academy
Ransomware victim Healthcare

Topcon Healthcare

Listed by Everest on · organisation based in Japan

Disclosed
Oct 13, 2026
Leak-site listing date
Threat group
Everest
284 victims listed
Country
Japan
#11 most targeted
Sector
Healthcare

ThreatAI analysis

Compiled from this incident record and the threat intelligence profile for Everest. Figures and technique mappings are quoted from the source data, not inferred.

About the Everest group

Everest ransom group collects and analyzes information about their victims. They specialize in customer privacy data, financial information, databases, credit card information, and more. The Everest ransom group leaks the victim's data to the darknet and they announced that any victim that will not contact them will suffer from a data leak and they will not delete hist files for future usage. Everest has listed 409 victims since September 2021.

How Everest is documented to operate

Obfuscated Files or Information T1027 Stealth

Adversaries may attempt to make an executable or file difficult to discover or analyze by encrypting, encoding, or otherwise obfuscating its contents on the system or in transit. This is common behavior that can be used across different platforms and the network to evade defenses. Payloads may be compressed, archived, or encrypted in order to avoid detection. These payloads may be used during Initial Access or later to mitigate detection. Sometimes a user's action may be required to open and Deobfuscate/Decode Files or Information for User Execution. The user may also be required to input a password to open a password protected compressed/encrypted file that was provided by the adversary.

Mitigations: User Training, Behavior Prevention on Endpoint, Antivirus/Antimalware, Audit

MITRE ATT&CK reference
Modify Registry T1112 Defense Impairment Persistence

Adversaries may interact with the Windows Registry as part of a variety of other techniques to aid in defense evasion, persistence, and execution. Access to specific areas of the Registry depends on account permissions, with some keys requiring administrator-level access. The built-in Windows command-line utility Reg may be used for local or remote Registry modification. Other tools, such as remote access tools, may also contain functionality to interact with the Registry through the Windows API. The Registry may be modified in order to hide configuration information or malicious payloads via Obfuscated Files or Information.

Mitigations: Restrict Registry Permissions

MITRE ATT&CK reference
Deobfuscate/Decode Files or Information T1140 Stealth

Adversaries may use Obfuscated Files or Information to hide artifacts of an intrusion from analysis. They may require separate mechanisms to decode or deobfuscate that information depending on how they intend to use it. Methods for doing that include built-in functionality of malware or by using utilities present on the system. One such example is the use of certutil to decode a remote access tool portable executable file that has been hidden inside a certificate file. Another example is using the Windows <codecopy /b</code or <codetype</code command to reassemble binary fragments into a malicious payload.

MITRE ATT&CK reference
Execution Guardrails T1480 Stealth

Adversaries may use execution guardrails to constrain execution or actions based on adversary supplied and environment specific conditions that are expected to be present on the target. Guardrails ensure that a payload only executes against an intended target and reduces collateral damage from an adversary’s campaign. Values an adversary can provide about a target system or environment to use as guardrails may include specific network share names, attached physical devices, files, joined Active Directory (AD) domains, and local/external IP addresses. Guardrails can be used to prevent exposure of capabilities in environments that are not intended to be compromised or operated within.

Mitigations: Do Not Mitigate

MITRE ATT&CK reference

MITRE ATT&CK techniques attributed to Everest across its recorded activity, not a finding about how Topcon Healthcare was reached.

Incident analysis

Topcon Healthcare was listed by Everest ransomware, a group with 284 victims recorded in this database. The listing appeared on the group's leak site on October 13, 2026.

Topcon Healthcare is based in Japan and operates in the Healthcare sector. Japan ranks #11 worldwide for ransomware disclosures, with 297 victims in this database.

Sector context. Healthcare organisations are high-value ransomware targets because patient data is extremely sensitive, regulatory penalties for breaches are severe, and operational downtime can threaten patient safety — all factors that increase ransom payment pressure.

Everest typically follows a double extortion model: data is exfiltrated from the victim's systems before files are encrypted, so the victim faces two demands at once — pay to restore access, and pay to keep stolen data unpublished. The leak site, where this listing appeared, is the lever for the second demand.

Source. Public leak-site disclosures aggregated via the ransomware.live API. The disclosure date is when the listing was published, which can differ from the date of compromise. This site does not publish or link to stolen data. Last updated .

Frequently asked questions

Was Topcon Healthcare attacked by ransomware?

Yes. Topcon Healthcare was listed as a victim of the Everest ransomware group on October 13, 2026. The organisation is based in Japan and operates in the Healthcare sector. The disclosure appeared on the group's dark web leak site.

Which ransomware group attacked Topcon Healthcare?

Topcon Healthcare was attacked by Everest ransomware. Everest is one of the most active ransomware groups, having claimed 284 victims globally. The group typically employs a double-extortion model: encrypting the victim's files and threatening to publish stolen data.

When did the Topcon Healthcare ransomware attack occur?

The ransomware attack on Topcon Healthcare was disclosed on October 13, 2026. This date reflects when the victim was published on the threat group's leak site, which may differ from the actual date of initial compromise.

What data was stolen in the Topcon Healthcare ransomware attack?

The specific data stolen from Topcon Healthcare has not been independently verified by this platform. Ransomware groups typically exfiltrate data before encrypting systems and use the threat of publication to pressure victims. As a Healthcare organisation, Topcon Healthcare likely held patient records, medical data, and personally identifiable information (PII).

How can organisations protect against Everest attacks?

To defend against Everest and similar threat actors, organisations should: maintain regular offline backups tested for restoration; implement network segmentation to limit lateral movement; deploy multi-factor authentication on all remote access; use endpoint detection and response (EDR) tools; conduct regular phishing and security awareness training; and monitor threat intelligence feeds for indicators of compromise (IOCs) associated with active groups.