Ransomware attacks in 2021: 1,437 confirmed incidents

// CONFIRMED RANSOMWARE ATTACKS · YEAR

Ransomnews has confirmed 1,437 ransomware attacks in 2021, the most recent in December 2021, each one verified against a public source such as a breach notification, regulatory filing, court record or press report. That is 15.1% of the 9,520 confirmed incidents in the dataset. That is 17% more than the 1,229 confirmed in 2020. The United States accounts for 706 of them (49%), with victims recorded in 66 countries in total. The most affected sector is healthcare, with 231 confirmed victims (16%). Where the operator is attributed, Conti leads with 126 confirmed victims. A ransom payment is on the public record in 44 cases and a refusal in 267; the outcome is unrecorded in the remaining 1,126.

Confirmed ransomware attacks by month, 2021

Confirmation lags the attack, sometimes by months, so the most recent months of the current year are provisional and fill in as disclosures, filings and reporting catch up.

Which ransomware groups had the most confirmed victims in 2021

The operator is attributed in 753 of the 1,437 confirmed incidents. Counts are confirmed victims, not leak-site claims, so they run well below the totals the groups publish about themselves. Group names link to the live Ransomtracker profile where one exists.

Where the confirmed attacks in 2021 fall

Country shares carry a reporting bias. United States breach-notification law and SEC disclosure rules push far more incidents onto the public record than most jurisdictions, which makes American attacks easier to confirm and inflates the US share of any confirmed dataset.

Ransom payment outcomes in 2021

Among the 311 confirmed incidents in 2021 where the outcome is on the public record, 44 paid and 267 refused, a disclosed payment rate of 14.1%. The remaining 1,126 carry no public statement either way. Victims that pay have every incentive to stay quiet and public bodies are the most likely to announce a refusal, so treat this as the disclosed rate, not the true one. The ransomware payment rate analysis explains how the disclosed rate has moved since 2018 and how it compares with incident-response firm samples.

Largest confirmed ransomware attacks in 2021 by records exposed

Record counts are recorded only where a named source disclosed them, which is the minority of cases, so this table ranks disclosed impact rather than true impact.

Most recent confirmed ransomware attacks in 2021

The 25 most recently confirmed of 1,437 incidents, newest first. Every row links to the public source it was verified against.

Frequently asked questions

How to read this page. Every incident counted here was verified by Ransomnews against at least one public source. Leak-site listings alone do not qualify, because operators inflate, duplicate and occasionally fabricate claims, so these totals are a defensible floor rather than a full census. Records exposed and ransom outcomes appear only where a named source disclosed them. The page is regenerated from the live database, which refreshes weekly. Cite as: Ransomnews Confirmed Ransomware Attacks Dataset, ransomnews.com, with a link to this page. Bulk access and methodology questions: [email protected]. See also the monthly ransomware statistics and the Ransomtracker.