killsec is a ransomware operator currently active on public leak sites. Darkfield has indexed 279 public victims claimed by this operator between March 21, 2024 and May 14, 2026. killsec is a relatively new ransomware group that emerged in March 2024, operating with apparent financial motivations and demonstrating broad targeting across multiple geographic regions and industry sectors. The group's origin and potential state affiliations remain unclear due to limited public documentation from major threat intelligence sources, though their targeting pattern suggests opportunistic rather than geopolitically motivated operations. With 276 documented victims primarily concentrated in the United States, India, the United Kingdom, Brazil, and Belgium, killsec appears to focus heavily on healthcare, technology, business services, and financial sectors, indicating either specific tooling designed for these environments or opportunistic targeting of organizations with valuable data and high pressure to restore operations quickly. Given the group's recent emergence and the lack of detailed technical analysis from established cybersecurity firms like Mandiant or law enforcement advisories from CISA or FBI, specific details about their attack methodology, initial access vectors, encryption techniques, and extortion tactics have not been publicly documented in authoritative sources. The group remains active as of current reporting, though the limited intelligence profile suggests they may be either a smaller operation or one that has not yet attracted significant attention from major threat intelligence organizations despite their substantial victim count.
How we know this. Operator profiles on Darkfield are built from continuous monitoring of every leak site the group is known to operate, cross-correlated with community-curated feeds (RansomLook, ransomware.live, RansomWatch, MISP-galaxy). Status flips from active to inactive when no new disclosure appears for 60 days. MITRE ATT&CK mappings shown in the interactive section below are sourced from CISA, vendor analysis, and the MITRE community catalog — we attribute each technique back to its source. Aliases reflect operator re-brands and affiliate splits.