Was NTT Docomo - Japan 1st Mobile Operator hit by ransomware?

NTT Docomo - Japan 1st Mobile Operator was listed by the Ransomedvc ransomware operation (Japan), and stolen data was published on the group's leak site. Darkfield tracks this disclosure with the original leak post, screenshot and group context.

Who is the Ransomedvc ransomware group?

Ransomedvc is a ransomware operator tracked by Darkfield. See the full operator dossier for its known victims, sectors targeted, IOCs and leak-site infrastructure.

What data was leaked in the NTT Docomo - Japan 1st Mobile Operator breach?

Ransomedvc published data attributed to NTT Docomo - Japan 1st Mobile Operator, around 310.000 employees records. Darkfield captured the leak post and a screenshot of the listing.

Ransomware victim disclosure

← All victims

NTT Docomo (NTT Group)

listed as NTT Docomo - Japan 1st Mobile Operator · Claimed by Ransomedvc · listed 3 years ago

310.000 employees

Records

$1.015

Ransom

demanded

34m

Age

since listed · data leaked

Status timeline

ListedSep 26, 2023
Data leakeddate unknown

At a glance

Group: Ransomedvc
Status: Data leaked
Country: Japan
Sector: Telecommunications
Listed on leak site: Sep 26, 2023
Records: 310.000 employees
Ransom demanded: $1.015

About the victim

AI dossier — public-source company profile

NTT Docomo is Japan's largest mobile operator, operating under the NTT (Nippon Telegraph and Telephone Corporation) group, which employs approximately 310,000 people worldwide. The group provides a wide range of services including fixed-line telephony, mobile communications, internet services, and system integration. NTT is reported to serve 88% of the Fortune 500's top 100 companies globally.

Industry: Telecommunications & Mobile Services
Employees: 310000

Attack summary

Severity: high — The group claims full exfiltration from a major global telecommunications carrier serving hundreds of thousands of enterprise clients including Fortune 500 companies; however, no specific data inventory or proof files have been published, and the data size is unstated, preventing a critical classification.

RansomedVC claims to have infiltrated NTT's infrastructure and exfiltrated data, demanding a ransom of $1,015,000. The group states the attack was triggered by non-payment, and describes having extracted 'everything' from the compromised environment.

high

Data the group says was taken

AI dossier — extracted from the leak post

Exfiltrated internal data (unspecified)
Potentially corporate/enterprise client data
Potentially network/infrastructure data

What the group claims

With approximately 310,000 employees worldwide, NTT (Nippon Telegraph and Telephone Corporation) is one of the world's leading telecommunications carriers. It is chosen by as many as 88% of the top 100 companies in the Fortune Global Business Ranking "Fortune 500", an annual U.S. business magazine. We offer a wide range of services in Japan, from fixed-line and mobile phones to the Internet and system integration.We have got into their base and exfiltrated everything from there, we dont get paid.We require a ransom of $1,015,000

Sources

Victim sitenttdocomo.co.jp

Source

Indexed 3 years ago

This page surfaces a public ransomware disclosure indexed by Darkfield. Original posts come from the operator's own leak site; we cross-check against ransomware.live, RansomLook and RansomWatch where applicable. Share this URL freely.

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Disclosure context

About Ransomedvc

Ransomedvc is a financially-motivated ransomware group that emerged in August 2023, representing one of the newer entrants in the ransomware ecosystem with a documented victim count of 68 organizations. Given the group's recent emergence and limited public documentation from major cybersecurity organizations, specific details about their country of origin and operational structure remain unclear, though their targeting patterns suggest they operate as an independent group rather than a established RaaS operation. The group demonstrates a preference for targeting critical infrastructure sectors, particularly focusing on Food & Agriculture and Healthcare organizations across a geographically diverse range of countries including Bulgaria, Brazil, Japan, Australia, and Russia, indicating either a broad opportunistic approach or the use of automated scanning tools to identify vulnerable systems. While comprehensive details about their specific attack methodologies, encryption techniques, and whether they employ double or triple extortion tactics have not been extensively documented by major threat intelligence firms, their targeting of healthcare and food sector organizations suggests they may leverage the critical nature of these services to pressure victims into payment. The group's notable campaign activity appears concentrated in their operational period since mid-2023, though no major high-profile attacks or significant law enforcement actions have been publicly reported by CISA, FBI, or other authoritative sources. Ransomedvc appears to remain active as of the latest available intelligence, though their relatively recent emergence means their long-term operational patterns and potential for rebranding or law enforcement disruption remain to be observed. The group has been linked to 68 public disclosures across our corpus. First observed on a leak site on August 21, 2023; most recent post October 30, 2023. The operation is currently inactive.

Timeline of this disclosure

September 26, 2023NTT Docomo - Japan 1st Mobile Operator listed by Ransomedvcon the group's public leak site

Records: 310.000 employees
Ransom demanded: $1.015

Other recent disclosures by Ransomedvc

Ransomedvc has been linked to 68 public victims on Darkfield. A sample of the most recent:

See the full Ransomedvc dossier →

Sector and geography

This disclosure adds to ransomware activity in the Telecommunications sector, which has 87 disclosures indexed across all operators we track. Geographically, NTT Docomo - Japan 1st Mobile Operator is reported in Japan, a country with 220 ransomware disclosures in our corpus.

If your organisation is affected

A listing by Ransomedvc means NTT Docomo - Japan 1st Mobile Operator appeared on a ransomware extortion site and data attributed to it has been published. If this is your organisation, or a supplier you depend on, the priority is to confirm the intrusion and contain it before the window to act closes.

Engage your incident-response team and preserve forensic evidence before remediating — do not wipe affected systems first.
Force a password reset and revoke active sessions for exposed accounts; rotate any credentials, API keys or certificates that may have been in the stolen data.
Assess regulatory notification duties (GDPR, NIS2, sector regulators) — many carry a 72-hour reporting clock from awareness.
Report the incident to your national CERT, JPCERT/CC (Japan), as required for your jurisdiction.
Monitor for the data appearing on Ransomedvc's leak site and across paste and breach channels, and brief downstream partners who may be exposed through you.

How we know this. Darkfield monitors public ransomware leak sites continuously, archiving every new disclosure and the data later released against the victim. Each entry on this page is sourced from the operator's own publication and cross-checked against complementary OSINT feeds (RansomLook, ransomware.live, RansomWatch). We do not collect or host stolen data — only the metadata, timestamps and screenshots needed to make the public disclosure searchable and accountable. Records here are corrected when the original post is edited, retracted, or merged with another disclosure.