Based on publicly available information, Radiant is an emerging ransomware group that was first observed in October 2025, representing one of the newer threats in the ransomware landscape with a relatively small footprint of eight documented victims to date. The group appears to be financially motivated, following the typical ransomware business model of encrypting victim data and demanding payment for decryption keys. Limited intelligence suggests the group operates independently rather than as a ransomware-as-a-service operation, though insufficient data exists to definitively establish their country of origin or potential affiliations with other cybercriminal organizations. Due to the group's recent emergence and limited victim count, specific details regarding their attack methodology, initial access vectors, and technical capabilities remain largely undocumented by major security research organizations. Their targeting pattern shows a geographic focus on Western nations including the United States, Netherlands, Germany, United Kingdom, and Finland, with victim organizations spanning healthcare, transportation and logistics, agriculture and food production, and consumer services sectors. Given the group's recent emergence in late 2025, there are no documented major campaigns, high-profile attacks, or law enforcement actions against Radiant at this time. The group appears to remain active as of current reporting, though their limited operational history and small victim count suggest they are either in early operational phases or operating at a relatively small scale compared to established ransomware enterprises. The group has been linked to 8 public disclosures across our corpus. First observed on a leak site on October 12, 2025; most recent post October 29, 2025. The operation is currently inactive.
Sector and geography
This disclosure adds to ransomware activity in the Transportation/Logistics sector, which has 1,081 disclosures indexed across all operators we track. Geographically, UK Rail Services is reported in United Kingdom, a country with 1,217 ransomware disclosures in our corpus.
If your organisation is affected
A listing by radiant means UK Rail Services 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, NCSC (United Kingdom), as required for your jurisdiction.
- Monitor for the data appearing on radiant'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.
