Weyhro is an emerging ransomware group that was first observed in March 2025, appearing to be primarily financially motivated based on their targeting patterns and operational behavior. The group's origin and affiliations remain unclear due to their recent emergence, with insufficient public documentation from major threat intelligence sources to confirm their country of origin, potential links to established ransomware families, or whether they operate under a Ransomware-as-a-Service model. With only 14 documented victims since their March 2025 debut, specific details about their attack methodology, initial access vectors, encryption techniques, and data exfiltration practices have not been comprehensively documented by CISA, FBI, Mandiant, or other reputable security researchers. The group has demonstrated a geographically diverse targeting approach, primarily focusing on victims in the United States, Germany, Canada, Barbados, and Italy, with a sector preference for manufacturing, financial services, business services, and technology organizations. Given the group's recent emergence and limited victim count, no major high-profile campaigns, record ransom demands, or law enforcement actions have been publicly reported. Weyhro appears to remain active as of current reporting, though their operational tempo and long-term sustainability remain to be determined given the limited intelligence available on this nascent threat actor. The group has been linked to 14 public disclosures across our corpus. First observed on a leak site on March 6, 2025; most recent post August 11, 2025. The operation is currently inactive.
Sector and geography
This disclosure adds to ransomware activity in the Manufacturing sector, which has 2,458 disclosures indexed across all operators we track. Geographically, McMillan James Equipment Company (MJEC) is reported in United States, a country with 7,392 ransomware disclosures in our corpus.
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.
