Gunra is an emerging ransomware group that was first observed in April 2025, operating with primarily financial motivations based on their targeting patterns across multiple high-value sectors. The group's origin and affiliations remain unclear due to limited public documentation from major security vendors, though their geographic targeting suggests possible international operations given their focus on victims across Brazil, South Korea, Japan, Canada, and Egypt. With approximately 20 known victims to date, Gunra appears to follow conventional ransomware attack methodologies typical of financially-motivated cybercriminal groups, though specific technical details regarding their initial access vectors, encryption methods, or use of double extortion tactics have not been publicly documented by major threat intelligence sources. The group demonstrates opportunistic targeting behavior, focusing primarily on manufacturing organizations while also compromising entities in healthcare, technology, and financial services sectors, suggesting they may operate opportunistically rather than with highly specialized sector expertise. Given the recent emergence of this group in April 2025 and limited public reporting from established threat intelligence organizations such as CISA, FBI, or major security vendors, Gunra's current operational status, technical capabilities, and long-term threat trajectory require continued monitoring as more intelligence becomes available. The group has been linked to 46 public disclosures across our corpus. First observed on a leak site on April 23, 2025; most recent post July 10, 2026. The operation is currently active.
Sector and geography
This disclosure adds to ransomware activity in the Manufacturing sector, which has 3,681 disclosures indexed across all operators we track. Geographically, TOMOKU CO., LTD. is reported in Japan, a country with 220 ransomware disclosures in our corpus.
If your organisation is affected
A listing by gunra means TOMOKU CO., LTD. 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 gunra'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.
