// CONFIRMED RANSOMWARE ATTACKS · MONTH
Ransomnews has confirmed 120 ransomware attacks in May 2023, each one verified against a public source such as a breach notification, regulatory filing, court record or press report. That is 1.3% of the 9,520 confirmed incidents in the dataset. That compares with 162 in April 2023 and 79 in May 2022. The United States accounts for 61 of them (51%), with victims recorded in 26 countries in total. The most affected sector is government, with 21 confirmed victims (18%). Where the operator is attributed, LockBit leads with 16 confirmed victims. A ransom payment is on the public record in 2 cases and a refusal in 27; the outcome is unrecorded in the remaining 91.
Confirmed ransomware attacks by month, trailing 13 months to May 2023
Every month is a partial count until disclosures stop arriving, which typically takes three to four months. Compare May 2023 with months of the same age rather than with fully matured ones.
| Month | Confirmed attacks |
|---|---|
| May 2022 | 79 |
| June 2022 | 76 |
| July 2022 | 60 |
| August 2022 | 73 |
| September 2022 | 85 |
| October 2022 | 87 |
| November 2022 | 79 |
| December 2022 | 85 |
| January 2023 | 96 |
| February 2023 | 146 |
| March 2023 | 136 |
| April 2023 | 162 |
| May 2023 | 120 |
Which ransomware groups had the most confirmed victims in May 2023
The operator is attributed in 86 of the 120 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.
Most active groups by confirmed victims
Where the confirmed attacks in May 2023 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.
Most affected countries
Most affected sectors
Ransom payment outcomes in May 2023
Among the 29 confirmed incidents in May 2023 where the outcome is on the public record, 2 paid and 27 refused, a disclosed payment rate of 6.9%. The remaining 91 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 May 2023 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.
| Date | Organisation | Sector | Location | Records | Group | Ransom paid | Source |
|---|---|---|---|---|---|---|---|
| May 2023 | MOVEit (Ipswitch) | Technology | Massachusetts, United States | 95,788,491 | Clop | Unknown | socradar.io |
| May 2023 | Norton Healthcare | Healthcare | Kentucky, United States | 2,500,000 | ALPHV/BlackCat | No | nortonhealthcare.com |
| May 2023 | Tampa General Hospital | Healthcare | Florida, United States | 2,430,920 | — | No | therecord.media |
| May 2023 | Richmond University Medical Center | Healthcare | New York, United States | 674,033 | — | Unknown | silive.com |
| May 2023 | Mountain View Hospital | Healthcare | Idaho, United States | 441,903 | — | Unknown | eastidahonews.com |
| May 2023 | Houser, LLP | Legal | California, United States | 370,001 | ALPHV/BlackCat | Unknown | oag.ca.gov |
| May 2023 | Greylock McKinnon Associates Inc. | Legal | Massachusetts, United States | 341,650 | — | Unknown | apps.web.maine.gov |
| May 2023 | Fairfax Oral and Maxillofacial Surgery | Healthcare | Virginia, United States | 235,931 | — | Unknown | apps.web.maine.gov |
| May 2023 | Bunker Hill Community College | Education | Massachusetts, United States | 195,588 | Snatch | Unknown | databreaches.net |
| May 2023 | Columbus Regional Healthcare System | Healthcare | North Carolina, United States | 132,887 | Daixin | No | jdsupra.com |
All confirmed ransomware attacks in May 2023
All 120 of 120 confirmed incidents. Every row links to the public source it was verified against.
| Date | Organisation | Sector | Location | Records | Group | Ransom paid | Source |
|---|---|---|---|---|---|---|---|
| May 2023 | mk Technology Group | Manufacturing | Troisdorf, Germany | — | Akira | Unknown | mk-group.com |
| May 2023 | Raleigh Housing Authority | Government | North Carolina, United States | — | Black Basta | Unknown | therecord.media |
| May 2023 | Tribunal Superior do Trabalho (TST) | Government | Brasilia, Brazil | — | 8Base | Unknown | contabeis.com.br |
| May 2023 | Dalvikurbyggd | Government | Dalvikurbyggd, Iceland | — | LockBit | No | dalvikurbyggd.is |
| May 2023 | Western Cape Provincial Parliament (WCPP) | Government | Cape Town, South Africa | — | — | Unknown | iol.co.za |
| May 2023 | Nuclebrás Equipamentos Pesados (NUCLEP) | Government | Itaguai, Brazil | — | Meow | Unknown | gov.br |
| May 2023 | Nippon Concrete Industries Co., Ltd. | Manufacturing | Minato City, Japan | — | — | Unknown | ncic.co.jp |
| May 2023 | Adstra, LLC | Service | New Jersey, United States | 1,951 | LockBit | Unknown | maine.gov |
| May 2023 | The Sullivan Group Of Court Reporters | Legal | California, United States | — | BianLian | Unknown | thesullivangroupofcourtreporters.com |
| May 2023 | Greylock McKinnon Associates Inc. | Legal | Massachusetts, United States | 341,650 | — | Unknown | apps.web.maine.gov |
| May 2023 | Simmons Perrine Moyer Bergman PLC | Legal | Iowa, United States | 2,391 | LockBit | Unknown | apps.web.maine.gov |
| May 2023 | Asakura Robinson Company, LLC | Service | Texas, United States | 263 | Akira | Unknown | marylandattorneygeneral.gov |
| May 2023 | The Dufresne Spencer Group, LLC | Retail | Tennessee, United States | 61,744 | ALPHV/BlackCat | Unknown | apps.web.maine.gov |
| May 2023 | Alliance Solutions Group dba TalentLaunch | Service | Ohio, United States | 119,261 | Black Basta | Unknown | doj.nh.gov |
| May 2023 | Burch & Cracchiolo, PA | Legal | Arizona, United States | — | ALPHV/BlackCat | Unknown | ago.vermont.gov |
| May 2023 | Eastside Union School District | Education | California, United States | 3,592 | Karakurt | Unknown | apps.web.maine.gov |
| May 2023 | Future Generations Foundation (NIB Trust Fund) | Other | Akwesasne, Canada | — | — | Unknown | fgfoundation.ca |
| May 2023 | National Association of Home Builders | Construction | District of Columbia, United States | 2,020 | Akira | Unknown | apps.web.maine.gov |
| May 2023 | Houser, LLP | Legal | California, United States | 370,001 | ALPHV/BlackCat | Unknown | oag.ca.gov |
| May 2023 | Jeff Wyler Automotive Family | Retail | Ohio, United States | 76,038 | 8Base | Unknown | apps.web.maine.gov |
| May 2023 | Maxxis International | Manufacturing | Georgia, United States | 1,100 | — | Unknown | dojmt.gov |
| May 2023 | Ascendum Machinery, Inc. | Manufacturing | North Carolina, United States | — | ALPHV/BlackCat | Unknown | dojmt.gov |
| May 2023 | Marjam Supply Company (bought by Foundation Building Materials, LLC) | Retail | New York, United States | 7,957 | BlackSuit | Unknown | apps.web.maine.gov |
| May 2023 | Transporto Kompetencijų Agentūra | Government | Vilnius, Lithuania | — | Cuba | Unknown | tka.lt |
| May 2023 | Cohen Buchan Edwards LLP | Legal | Richmond, Canada | — | LockBit | Unknown | cbelaw.com |
| May 2023 | Wianno Club | Other | Massachusetts, United States | 1,731 | LockBit | Unknown | apps.web.maine.gov |
| May 2023 | BankCard USA Merchant Services Inc. | Finance | California, United States | 10,312 | Black Basta | Yes | suspectfile.com |
| May 2023 | STI Holdings, Inc | Manufacturing | Wisconsin, United States | 4,294 | Akira | Unknown | apps.web.maine.gov |
| May 2023 | The Hillman Group | Manufacturing | Ohio, United States | 6,410 | — | Unknown | ir.hillmangroup.com |
| May 2023 | It Works Marketing, Inc. | Retail | Florida, United States | 301 | ALPHV/BlackCat | Unknown | apps.web.maine.gov |
| May 2023 | Stanford University Department of Public Safety | Education | California, United States | 27,000 | Akira | Unknown | therecord.media |
| May 2023 | BHI Energy | Service | Massachusetts, United States | 91,269 | Akira | No | iowaattorneygeneral.gov |
| May 2023 | Columbus Regional Healthcare System | Healthcare | North Carolina, United States | 132,887 | Daixin | No | jdsupra.com |
| May 2023 | Andromeda Systems, Inc. | Service | Virginia, United States | 2,670 | Black Basta | Unknown | apps.web.maine.gov |
| May 2023 | Fairfax Oral and Maxillofacial Surgery | Healthcare | Virginia, United States | 235,931 | — | Unknown | apps.web.maine.gov |
| May 2023 | Taylor University | Education | Indiana, United States | 811 | Money Message | Unknown | theechonews.com |
| May 2023 | O’Brien Steel Service Co. | Manufacturing | Illinois, United States | 2,586 | Akira | Unknown | apps.web.maine.gov |
| May 2023 | San Francisco Jazz Organization (SFJAZZ) | Other | California, United States | — | LockBit | Unknown | oag.ca.gov |
| May 2023 | Adams Bank & Trust | Finance | Nebraska, United States | 23,819 | Black Basta | Unknown | starherald.com |
| May 2023 | Northern Ontario School of Medicine (NOSM) University | Education | Ontario, Canada | — | LockBit | Unknown | insurancebusinessmag.com |
| May 2023 | Loreto Toorak (Loreto Normanhurst) | Education | Toorak, Australia | — | Medusa | Unknown | loretotoorak.vic.edu.au |
| May 2023 | Caisse des Ecoles du Robert | Education | Le Robert, Martinique | — | — | Unknown | zayactu.org |
| May 2023 | Unico Data | Technology | Münsingen, Switzerland | — | Play | No | inside-it.ch |
| May 2023 | New England Copy Specialists, Inc. | Retail | Massachusetts, United States | — | — | Unknown | mass.gov |
| May 2023 | Venture Transportation Partners, LLC | Transportation | Indiana, United States | 9,339 | BlackSuit | Unknown | apps.web.maine.gov |
| May 2023 | Federated Appraisal and Closing Services, LP | Service | Pennsylvania, United States | 840 | — | Unknown | apps.web.maine.gov |
| May 2023 | Bunker Hill Community College | Education | Massachusetts, United States | 195,588 | Snatch | Unknown | databreaches.net |
| May 2023 | Integrated Dynamics Engineering, Inc. | Manufacturing | Massachusetts, United States | 30 | — | Unknown | doj.nh.gov |
| May 2023 | Indiana Donor Network | Healthcare | Indiana, United States | 2,519 | — | Unknown | doj.nh.gov |
| May 2023 | Mitsubishi Chemical America, Inc. (Sporting Goods Division) | Manufacturing | New York, United States | 264 | — | Unknown | apps.web.maine.gov |
| May 2023 | City of Nassau Bay | Government | Texas, United States | 8,839 | Akira | Unknown | texasattorneygeneral.gov |
| May 2023 | Family Vision of Anderson, P.A. | Healthcare | South Carolina, United States | 62,631 | — | Unknown | apps.web.maine.gov |
| May 2023 | Metalnet | Manufacturing | Valkenswaard, Netherlands | — | LockBit | No | metaalnieuws.nl |
| May 2023 | Tampa General Hospital | Healthcare | Florida, United States | 2,430,920 | — | No | therecord.media |
| May 2023 | Fortescue Metals Group | Manufacturing | Adelaide, Australia | — | Clop | Unknown | itwire.com |
| May 2023 | Silicon Valley Mechanical, Inc. | Construction | California, United States | — | ALPHV/BlackCat | Unknown | oag.ca.gov |
| May 2023 | Mountain View Hospital | Healthcare | Idaho, United States | 441,903 | — | Unknown | eastidahonews.com |
| May 2023 | Casepoint | Technology | Virginia, United States | — | ALPHV/BlackCat | Unknown | cybernews.com |
| May 2023 | La Mairie de Mandeure | Government | Mndeure, France | — | LockBit | Unknown | francebleu.fr |
| May 2023 | Servei Municipal d'Abastament d'Aigua Potable de Lleida | Utilities | Lleida, Spain | — | — | Unknown | larepublica.cat |
| May 2023 | Fiduagraria SA | Government | Bogotá, Colombia | — | LockBit/Medusa | Unknown | fiduagraria.gov.co |
| May 2023 | Northeastern State University | Education | Oklahoma, United States | — | Rhysida | Unknown | govtech.com |
| May 2023 | Centre Hospitalier Régional Sambre et Meuse (CHRSM) | Healthcare | Namur, Belgium | — | NoEscape | No | rtbf.be |
| May 2023 | Granules India Limited | Healthcare | Hyderabad, India | — | LockBit | No | cnbctv18.com |
| May 2023 | Headwall Photonics, Inc. | Manufacturing | Massachusetts, United States | 236 | — | Unknown | apps.web.maine.gov |
| May 2023 | Forsyth County | Government | Georgia, United States | 1,726 | ALPHV/BlackCat | Unknown | apps.web.maine.gov |
| May 2023 | MOVEit (Ipswitch) | Technology | Massachusetts, United States | 95,788,491 | Clop | Unknown | socradar.io |
| May 2023 | Adams County Communication Center (ADCOM911) | Government | Pennsylvania, United States | — | Akira | Unknown | adamssheriff.org |
| May 2023 | Akron-Summit County Public Libraries | Government | Ohio, United States | — | — | Unknown | eu.beaconjournal.com |
| May 2023 | Middlesex County Public Schools | Education | Virginia, United States | — | Akira | No | wavy.com |
| May 2023 | Deutsche Energie-Agentur (Biogasregister Deutschland) | Government | Berlin, Germany | — | — | Unknown | csoonline.com |
| May 2023 | United Hoster | Technology | Stuttgard, Germany | — | — | No | csoonline.com |
| May 2023 | Germany Trade & Invest (GTAI) - Gesellschaft für Außenwirtschaft und Standortmarketing mbH | Government | Berlin, Germany | — | Play | No | b2b-cyber-security.de |
| May 2023 | Auto-Teile-Unger (ATU) | Service | Weiden, Germany | — | Black Basta | Unknown | br.de |
| May 2023 | Câmara de Lagoa | Government | Lagoa, Portugal | — | — | No | theportugalnews.com |
| May 2023 | Voyageurs du Monde | Service | Bordeaux, France | — | LockBit | No | linfo.re |
| May 2023 | The Michener Institute | Education | Ontario, Canada | — | Clop | Unknown | michener.ca |
| May 2023 | Collectivité Territoriale de Martinique | Government | Fort-de-France, Martinique | — | Rhysida | Unknown | therecord.media |
| May 2023 | YKK Group | Manufacturing | Tokyo, Japan | — | LockBit | No | manufacturing.net |
| May 2023 | Eisai Co. Ltd. | Healthcare | Tokyo, Japan | — | — | Unknown | japannews.yomiuri.co.jp |
| May 2023 | University of Waterloo | Education | Waterloo, Canada | — | — | Unknown | therecord.media |
| May 2023 | Xplain AG | Technology | Bern, Switzerland | — | Play | No | inside-it.ch |
| May 2023 | OSG Hengelo | Education | Hengelo, Netherlands | — | — | Yes | 1twente.nl |
| May 2023 | Chattanooga State Community College | Education | Tennessee, United States | 1,244 | Snatch | No | therecord.media |
| May 2023 | Norton Healthcare | Healthcare | Kentucky, United States | 2,500,000 | ALPHV/BlackCat | No | nortonhealthcare.com |
| May 2023 | Ejército de Chile (Chilean Army) | Government | Santiago, Chile | — | Rhysida | Unknown | meganoticias.cl |
| May 2023 | HECKER WERNER HIMMELREICH Rechtsanwälte Partnerschaft mbB | Legal | Köln, Germany | — | Black Basta | Unknown | hwhlaw.de |
| May 2023 | Universal Cranes (Smithbridge Group) | Construction | Murarrie, Australia | — | Ragnar Locker | Unknown | universalcranes.com |
| May 2023 | City of Augusta | Government | Georgia, United States | — | BlackByte | Unknown | wfxg.com |
| May 2023 | Madhya Pradesh Power Management Company Limited | Utilities | Madhya Pradesh, India | — | — | Unknown | energy.economictimes.indiatimes.com |
| May 2023 | Trabzonspor Football Club | Other | Trabzon, Turkey | — | Medusa | Unknown | trthaber.com |
| May 2023 | Black Cat Networks | Technology | Singen, Germany | — | Play | Unknown | csoonline.com |
| May 2023 | The Philadelphia Inquirer | Other | Pennsylvania, United States | 25,549 | Cuba | Unknown | bleepingcomputer.com |
| May 2023 | Syndicat Mixte Départemental d'Énergies de l'Ariège (SMDEA) | Government | Ariège, France | — | Qilin | No | gazette-ariegeoise.fr |
| May 2023 | ScanSource | Technology | South Carolina, United States | — | Cactus | Unknown | beststocks.com |
| May 2023 | Franklin County Public Schools | Education | Virginia, United States | — | — | No | wfxrtv.com |
| May 2023 | Canadian Nurses Association | Healthcare | Ottawa, Canada | — | Snatch | Unknown | itworldcanada.com |
| May 2023 | Thomas Hardye School | Education | Dorchester, United Kingdom | — | Rhysida | No | bbc.co.uk |
| May 2023 | Farmalink | Healthcare | Buenos Aires, Argentina | — | LockBit | No | clarin.com |
| May 2023 | Euskaltel | Utilities | Derio, Spain | — | LockBit | Unknown | bilbaohiria.com |
| May 2023 | Lacroix | Manufacturing | Saint-Herblain, France | — | — | Unknown | security.nl |
| May 2023 | Grupo DIS (Direct Info Service) | Technology | Lille, France | — | ALPHV/BlackCat | Unknown | usine-digitale.fr |
| May 2023 | KD Hospital | Healthcare | Ahmedabad, India | — | — | Unknown | ahmedabadmirror.com |
| May 2023 | Richmond University Medical Center | Healthcare | New York, United States | 674,033 | — | Unknown | silive.com |
| May 2023 | Dragos, Inc. | Technology | Maryland, United States | — | — | No | techtarget.com |
| May 2023 | Libyana | Utilities | Misrata, Libya | — | ALPHV/BlackCat | Unknown | libyaakhbar.com |
| May 2023 | Politécnico de Leiria | Education | Leiria, Portugal | — | Akira | Unknown | tugatech.com.pt |
| May 2023 | ABB | Technology | Zurich, Switzerland | — | Black Basta | Unknown | bleepingcomputer.com |
| May 2023 | Ayuntamiento de Tulancingo | Government | Tulancingo, Mexico | — | — | No | sintesis.com.mx |
| May 2023 | Grupo Fleury | Healthcare | São Paulo, Brazil | — | — | Unknown | thenationview.com |
| May 2023 | Maxim Markenprodukte GmbH & Co. KG | Manufacturing | Pulheim, Germany | — | — | No | csoonline.com |
| May 2023 | Dr. Felix Chan | Healthcare | Sydney, Australia | — | Medusa | Unknown | news.com.au |
| May 2023 | City of Dallas | Government | Texas, United States | 30,546 | Royal | Unknown | cnn.com |
| May 2023 | Bay Crest Partners | Finance | New York, United States | — | LockBit | Unknown | marylandattorneygeneral.gov |
| May 2023 | 360 Equipment Finance | Finance | Texas, United States | — | Clop | Unknown | 360equipmentfinance.com |
| May 2023 | Deutsche Leasing Gruppe | Finance | Bad Homburg, Germany | — | Black Basta | No | euractiv.com |
| May 2023 | Mazars Group | Finance | São Paulo, Brazil | — | ALPHV/BlackCat | Unknown | cybernews.com |
| May 2023 | Development Bank of Southern Africa (DBSA) | Finance | Johannesburg, South Africa | — | Akira | Unknown | timeslive.co.za |
| May 2023 | Mayberry Investments | Finance | Kingston, Jamaica | — | Play | No | radiojamaicanewsonline.com |
| May 2023 | Bank Syariah Indonesia | Finance | Jakarta, Indonesia | — | LockBit | No | tekno.tempo.co |
Frequently asked questions
How many ransomware attacks were confirmed in May 2023?
Ransomnews has confirmed 120 ransomware attacks in May 2023, each verified against a public source, against 162 in April 2023 and 79 in May 2022. The true total is higher, because many victims never disclose; confirmed counts are a floor, not a ceiling.
Is the May 2023 count final?
It is as settled as a confirmed count gets. May 2023 ended more than four months before the latest database refresh, so most late disclosures have arrived, though a confirmation can still be added whenever a new public source surfaces. The figure is recalculated from the live database on every load.
Which ransomware group had the most confirmed victims in May 2023?
LockBit, with 16 confirmed victims, followed by Akira (12) and ALPHV/BlackCat (12). These are confirmed victims, not leak-site claims, counted among the 86 incidents where the operator is attributed.
Which country had the most confirmed ransomware attacks in May 2023?
The United States, with 61 of the 120 confirmed incidents (51%). Germany is next with 9. Part of the gap is exposure and part is reporting: US breach-notification and SEC disclosure rules put more incidents on the public record than most jurisdictions.
Which sector was hit most by ransomware in May 2023?
Government, with 21 confirmed incidents (18% of the total). Education follows with 16, then Healthcare with 16.
What share of ransomware victims paid in May 2023?
Among the 29 confirmed incidents in May 2023 with a public outcome, 2 paid and 27 refused, a disclosed payment rate of 6.9%. Most victims never state whether they paid, and those who pay have the least reason to say so, so the disclosed rate understates real payment behaviour. The payment rate analysis tracks this figure since 2018.
What was the largest ransomware attack of May 2023 by records exposed?
MOVEit (Ipswitch) (Massachusetts, United States, May 2023), with 95,788,491 records exposed according to socradar.io. Record counts exist only where a source disclosed them, so this ranks disclosed impact.
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.