Kill Security 3.0 is a financially motivated ransomware group first observed in June 2026, representing an apparent iteration or rebranding of an earlier Kill Security lineage, with operational activity documented against at least 11 confirmed victims across multiple countries and sectors. Given the limited open-source intelligence available on this group at this time, attribution to a specific country of origin or affiliation with known threat actor clusters has not been publicly confirmed by CISA, the FBI, Mandiant, or other reputable security research organizations; however, the group's targeting patterns suggest deliberate sector selection consistent with data-rich, operationally sensitive environments. Based on observed victim telemetry, Kill Security 3.0 has demonstrated a preference for targeting organizations in the United States, United Kingdom, Canada, South Korea, and Morocco, with particular focus on healthcare technology and medical device companies, childcare management software providers, financial services and debt recovery firms, legal services organizations, and behavioral health tracking platforms — a targeting profile that suggests an interest in sensitive personal, financial, and medical data likely leveraged for double extortion purposes. No specific initial access vectors, encryption methodologies, or tooling have been publicly attributed to this group by authoritative sources as of the time of this writing, though the sector focus on data-sensitive industries is consistent with exfiltration-prior-to-encryption tactics commonly employed by contemporary ransomware operators. No major named campaigns, record ransom demands, or law enforcement actions against Kill Security 3.0 have been publicly documented, and its current operational status remains active based on first-observed dating, though the limited victim count suggests the group may still be in early operational phases or selectively targeting victims. The group has been linked to 11 public disclosures across our corpus. First observed on a leak site on June 4, 2026. The operation is currently active.
If your organisation is affected
A listing by Kill Security 3.0 means op4Fans 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.
- Monitor for the data appearing on Kill Security 3.0'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, recording every new disclosure and the moment the operator says the data was released. Each entry on this page is sourced from the operator's own publication, listed by an independent tracker (RansomLook) and checked against our own capture. 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.
