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Ransomware Victim Technology

tein.co.jp

Ransomware attack by Warlock · Disclosed November 6, 2025 · 🇯🇵 Japan

tein.co.jp

Date Disclosed
Nov 6, 2025
2025
Threat Group
Warlock
78 total victims
Country
🇯🇵 Japan
Industry
Technology

ThreatAI Analysis

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

About the Warlock group

The Warlock ransomware and operator(s) are believed to be attributed to Storm-2603, a China-based threat actor who is also known to have deployed LockBit ransomware. There's also a crossover between victims with Black Basta. Both are RaaS and have a long list of known and unknown affiliates. Having said that, this is possibly an affiliate (likely a cybergroup) of both of those groups. The Alliance & Association would technically be Encryptor Sharing, but this is realistically more of an "Old Affiliate" that created their own ransomware encryptor and operation. Warlock has listed 78 victims since April 2025.

Incident Analysis

tein.co.jp was targeted by Warlock ransomware, one of the most active ransomware groups in our database with 78 confirmed victims globally. The attack was disclosed on November 6, 2025, when tein.co.jp appeared on the group's dark web leak site.

tein.co.jp is based in Japan , operating in the Technology sector. Japan ranks #11 globally for ransomware attacks, with 266 victims in our database.

Sector context: Technology companies hold intellectual property, customer data, and source code — all highly valuable assets. A successful ransomware attack can also put downstream customers at risk through supply chain exposure.

Warlock typically employs a double extortion model: first exfiltrating sensitive data from the victim's systems, then deploying ransomware to encrypt files. Victims face two simultaneous threats — paying to restore access and paying to prevent publication of stolen data. The group's leak site publishes victim names and exfiltrated data as leverage.

Data source: This incident record is sourced from public ransomware group leak site disclosures aggregated via the ransomware.live API. Disclosure date reflects when the victim was published on the leak site, which may differ from the initial date of compromise. This platform does not publish or link to stolen data. Last data update: Sep 5, 2026 20:00 UTC.

Frequently Asked Questions

Was tein.co.jp attacked by ransomware?

Yes. tein.co.jp was listed as a victim of the Warlock ransomware group on November 6, 2025. The organisation is based in Japan and operates in the Technology sector. The disclosure appeared on the group's dark web leak site.

Which ransomware group attacked tein.co.jp?

tein.co.jp was attacked by Warlock ransomware. Warlock is one of the most active ransomware groups, having claimed 78 victims globally. The group typically employs a double-extortion model: encrypting the victim's files and threatening to publish stolen data.

When did the tein.co.jp ransomware attack occur?

The ransomware attack on tein.co.jp was disclosed on November 6, 2025. 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 tein.co.jp ransomware attack?

The specific data stolen from tein.co.jp 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 Technology organisation, tein.co.jp likely held source code, intellectual property, and customer data.

How can organisations protect against Warlock attacks?

To defend against Warlock 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.