Qilin Ransomware: Inside 2025-26's Most Active RaaS Group
The Nisura Team ·
Qilin has become the most active ransomware operation on record — by claimed-victim count it topped the leaderboard through 2025 and into 2026, with more than 1,500 organisations named on its leak site since launch. It is a ransomware-as-a-service (RaaS) brand, not a single gang, and the two ways its affiliates get in are exactly the two initial-access routes a Nisura assessment prices. Here’s who Qilin is, why it exploded, and what the Synnovis attack shows about the real-world cost. (Leak-site figures are claimed victims — read counts as direction, not a verified ledger.)
Who is Qilin?
Qilin surfaced in July 2022 as “Agenda,” a Go-language RaaS, and rebranded to Qilin — after a creature from Chinese mythology — later that year. Parts of the encryptor were rewritten in Rust for speed, cross-platform reach (Windows and Linux/ESXi) and harder reverse-engineering. Like every mature RaaS, Qilin runs the full stack of a criminal business: affiliate recruitment on underground forums, an affiliate panel, a double-extortion leak site and a negotiation portal. Affiliates reportedly keep 80–85% of each ransom, with the rest going to the core operators.
Why it exploded in 2025
Qilin’s surge is a story of consolidation. Through 2024–2025 the biggest names fell — LockBit was disrupted by law enforcement, ALPHV/BlackCat pulled an exit scam, and RansomHub went dark around April 2025. Their skilled affiliates needed a new home, and Qilin’s well-run platform absorbed them. The result: security vendors tracked Qilin as the single most active group by claimed victims — hundreds of organisations across 60+ countries, and one tracker (MOXFIVE) puts it at ~1,500 claims since launch, 500+ in 2026 alone. Its favoured sectors line up with the wider EU picture: healthcare, manufacturing, professional services and government.
Our own data agrees. In the Nisura EU Ransomware Tracker, Qilin is the most-claimed group in the EU this quarter (Q3 2026) — 66 of 313 EU claims to date, ahead of The Gentlemen (the crew that splintered from it):
EU claims by group · Q3 2026 to date
How Qilin gets in — and why it’s the exact risk Nisura models
Researchers consistently tie Qilin’s initial access to two paths above all — not exotic exploits:
- Stolen or purchased credentials — VPN and webmail logins bought from access brokers or lifted from infostealer logs, especially where MFA is missing. This is the credential vector — invisible to a port scan, and often the dominant path.
- Exposed remote-access appliances — internet-facing VPN/RDP and edge devices, sometimes via a known CVE. This is the external-exposure path a passive scan sees.
Those are the two initial-access routes Nisura’s engine prices for every organisation: known-exploited exposure on your perimeter, plus a non-CVE credential/RDP vector scaled by your identity exposure. Qilin isn’t doing anything novel — it’s industrialising the two doors most companies leave ajar.
The case that defined Qilin: Synnovis and the NHS
On 3 June 2024, Qilin affiliates hit Synnovis, a pathology provider for NHS hospitals in London. Initial access was through compromised credentials; an MFA gap has been widely cited as a contributing weakness. Before encrypting, the attackers exfiltrated data and issued a reported $50 million demand; when negotiations broke down they published roughly 400GB of sensitive patient data — names, dates of birth, NHS numbers and test results.
The operational damage was severe: blood testing halted across King’s College, Guy’s and St Thomas’, and Lewisham & Greenwich, forcing an O-negative blood shortage, the cancellation of 10,000+ outpatient appointments and postponement of 1,700+ operations. A subsequent review found the attack was a contributing factor in 170+ cases of patient harm — and, in one case, contributed to a patient’s death, a landmark acknowledgement of ransomware’s human toll. Synnovis later put its direct costs at more than £32 million and issued breach notifications in February 2026 after an ~18-month forensic review.
The lesson isn’t that healthcare is uniquely doomed — it’s that a single credential and a missing MFA control cascaded into a nine-figure, life-threatening event. That chain is measurable before it happens.
Can we project Qilin’s financial gains?
Honestly — not reliably, and it’s worth being clear about why. On-chain attribution for Qilin is thin: our Ransomwhere-based economics source returns no wallet data tied to the Qilin/Agenda family, and RaaS crews deliberately obscure revenue with fresh wallets, split payments and unknown pay rates. Any circulating “Qilin earned $X” figure is an estimate stacked on unknowns — victims claimed × an assumed pay rate × average ransom — which is exactly the kind of unsourced number we won’t put a euro sign on.
What is knowable is victim-side and documented: in the Synnovis case, a reported $50M demand and £32M+ in direct costs to a single organisation. So we flip the question. Nisura doesn’t estimate what an attacker earns — it estimates what a hit would cost you: your downtime, business interruption, forensics and regulatory liability, weighted by how reachable your perimeter and identities actually are. That’s a number you can source, defend, and act on — unlike a leak-site revenue guess.
What it means for you
Qilin picks targets by exposure and payability, not by sector prestige — and it gets in through unpatched edge devices and stolen logins. None of that is decided by whether you’re formally an NIS2 essential or important entity. Three steps, in order: confirm whether the Directive binds you with the NIS2 Scope Checker; watch the live picture on the EU Ransomware Tracker and read who’s leading the quarter in our Q3 2026 ransomware round-up; then turn it into your own number — run a free CRQ simulation to see your projected annual loss in euros from exactly these vectors.
Sources & references
- Check Point — Qilin Ransomware (Agenda): A Deep Dive.
- Barracuda — Qilin ransomware is growing, but how long will it last?
- MOXFIVE — Qilin Ransomware 2026: TTPs, Victims and Defense Guide.
- SOCRadar — Dark Web Profile: Qilin (Agenda) Ransomware.
- BleepingComputer — Synnovis notifies of data breach after 2024 ransomware attack, and HIPAA Journal / Infosecurity Magazine on the Synnovis patient-harm findings.
Leak-site victim counts are claimed incidents and vary by tracker. Attack details reflect public reporting on the Synnovis incident.
Frequently asked questions
Who is the Qilin ransomware group?
Qilin is a ransomware-as-a-service (RaaS) operation that emerged as "Agenda" in July 2022 and rebranded to Qilin later that year. Its encryptor was built in Go and partly rewritten in Rust, targeting Windows and Linux/ESXi. Affiliates reportedly keep 80–85% of each ransom. By claimed-victim count it became the most active ransomware brand in 2025 and into 2026, with 1,500+ organisations named since launch across 60+ countries.
Why did Qilin become the most active ransomware group?
Consolidation. As LockBit was disrupted, ALPHV/BlackCat exit-scammed and RansomHub went dark around April 2025, their skilled affiliates migrated to Qilin’s well-run platform. That influx pushed Qilin to the top of the leak-site leaderboard, concentrated in healthcare, manufacturing, professional services and government.
How does Qilin gain initial access?
Predominantly two ways: stolen or purchased credentials (VPN/webmail logins from access brokers or infostealer logs, especially where MFA is missing), and exposed internet-facing remote-access appliances (VPN/RDP and edge devices, sometimes via a known CVE) — rather than novel exploits. These map to the two initial-access vectors a Nisura assessment prices.
What was the Qilin attack on Synnovis and the NHS?
On 3 June 2024, Qilin affiliates compromised Synnovis, a pathology provider for London NHS hospitals, via stolen credentials. They demanded a reported $50M, then leaked ~400GB of patient data. The attack cancelled 10,000+ appointments and 1,700+ operations, caused an O-negative blood shortage, and a later review found it contributed to 170+ cases of patient harm — including a patient death. Synnovis put direct costs above £32M.