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Undisclosed educational organization
April 1, 2026
Beginning in April 2026, researchers observed the Backdoor.Mistic remote access trojan deployed on the network of at least one undisclosed educational organization. The backdoor enabled file upload and download, file manipulation, folder creation, and in-memory code execution. The victim's identity, location, affected systems, and any acquired information were not disclosed. SecurityWeek attributed the activity to Woodgnat, also known as KongTuke, while Broadcom assessed that Mistic may be associated with the group.
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Undisclosed insurance organization
April 1, 2026
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[ espionage, malware, finance ]
Beginning in April 2026, researchers observed the Backdoor.Mistic remote access trojan deployed on the network of at least one undisclosed insurance organization. The backdoor enabled file upload and download, file manipulation, folder creation, and in-memory code execution. The victim's identity, location, affected systems, and any acquired information were not disclosed. SecurityWeek attributed the activity to Woodgnat, also known as KongTuke, while Broadcom assessed that Mistic may be associated with the group.
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Undisclosed information technology organization
April 1, 2026
Beginning in April 2026, researchers observed the Backdoor.Mistic remote access trojan deployed on the network of at least one undisclosed information technology organization. The backdoor enabled file upload and download, file manipulation, folder creation, and in-memory code execution. The victim's identity, location, affected systems, and any acquired information were not disclosed. SecurityWeek attributed the activity to Woodgnat, also known as KongTuke, while Broadcom assessed that Mistic may be associated with the group.
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Undisclosed professional services organization
April 1, 2026
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[ espionage, malware, technology ]
Beginning in April 2026, researchers observed the Backdoor.Mistic remote access trojan deployed on the network of at least one undisclosed professional services organization. The backdoor enabled file upload and download, file manipulation, folder creation, and in-memory code execution. The victim's identity, location, affected systems, and any acquired information were not disclosed. SecurityWeek attributed the activity to Woodgnat, also known as KongTuke, while Broadcom assessed that Mistic may be associated with the group.
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State Enterprise Centre of Registers
April 1, 2026
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[ espionage, hack, government ]
The State Enterprise Centre of Registers detected unauthorized extraction of more than 600,000 records in early April 2026. The actor used login credentials assigned to institutions authorized to access the Real Estate and Legal Entities Registers. Lithuanian prosecutors suspected involvement by an unnamed foreign country, but no state or threat group was formally attributed. The exact intrusion date was not disclosed, so April 1 is used as the normalized month-only event date.
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CAMILLA Australia Pty Ltd
April 1, 2026
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[ leak, retail ]
In April 2026, an unauthorized third party accessed CAMILLA Australia Pty Ltd's Australian network and exfiltrated customer records held within its point-of-sale system. CAMILLA secured its systems, notified affected customers and the Australian privacy regulator, and said its operations and order processing continued without disruption.
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Global Schools Group (Global Schools Foundation)
April 1, 2026
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[ leak, misconfiguration, education ]
FulcrumSec reportedly accessed Global Schools Group's AWS environment in April 2026 using default or reused credentials and obtained data from 67 S3 buckets, five MSSQL servers, and four MongoDB servers. The group claimed to have stolen 4.8 TB and later released a 221 GB highlights archive following failed extortion negotiations. Global Schools Group confirmed a cybersecurity incident, said it had contained it and restored affected systems, and notified authorities, but did not verify FulcrumSec's figures or specific data claims. No operational disruption was reported.
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James Fallon High School
April 1, 2026
James Fallon High School in North Albury, NSW, Australia, suffered a cyber data breach identified in April 2026 from a source outside NSW, exposing school documents and some student, parent and staff data. The education department and Cyber NSW concluded their probe in September.
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Fudbalski savez Srbije (Football Association of Serbia)
April 1, 2026
Hackers stole personal data of 11,000+ people who stayed at the Football Association of Serbia's sports center hotel in Stara Pazova, demanded money in Apr 2026, then posted the data on a dark web forum. Serbian police named FSS among INF Grupa targets after 27 Aug arrests.
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Sports Center of the Football Association of Serbia
April 1, 2026
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[ ransomware, technology ]
Belgrade prosecutors detained suspect L.D. in Aug 2026, alleging he accessed the Football Association of Serbia Sports Center's network from April to August 2026, took a large amount of data, demanded ransom and damaged data in a ransomware attack.
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Republic Health Insurance Fund of Serbia (RFZO)
April 1, 2026
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[ ransomware, healthcare, government ]
Serbian police arrested three INF Grupa members in Aug 2026; prosecutors allege suspect L.D. accessed the network of Serbia's Republic Health Insurance Fund (RFZO) between April and August 2026, took a large amount of data, demanded ransom and damaged data in a ransomware attack.
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Karl Chevrolet, Inc. (d/b/a Karl Auto Group)
April 3, 2026
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[ ransomware, leak, retail ]
An unauthorized third party gained access to certain Karl Auto Group computer systems before 2026-03-27. RansomHouse later claimed that it encrypted Karl Chevrolet systems on 2026-04-03, but Karl Auto Group did not publicly confirm the attribution or ransomware deployment. The company discovered the incident on 2026-04-04, when employees encountered unavailable phones and computers. Phone service remained disrupted or intermittent through at least 2026-04-08, although dealerships remained open and directed customers to email, online messages, or in-person service. Karl Auto Group stated that files containing personal information belonging to current and former customers, employees, and other individuals may have been accessed; thousands of customers were notified, but the total number affected was not disclosed. The company reported no evidence of misuse and said it did not pay a ransom.
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Karl Auto Group
April 4, 2026
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[ ransomware, automotive ]
Karl Auto Group discovered unauthorized access to certain business computer systems on April 4, 2026 after access had begun before March 27. Employees at multiple Iowa dealerships lacked working phones and computers, and phone service remained unavailable or intermittent for at least five days, although locations remained open. The company stated that files containing customer and employee information may have been accessed. RansomHouse separately claimed that Karl Chevrolet was encrypted on April 3, but Karl Auto Group did not confirm ransomware, data theft, or a connection to the group.
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Rostelecom
April 6, 2026
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[ ddos, technology ]
Rostelecom said a large-scale DDoS attack targeted its network on April 6, 2026, affecting availability of some internet resources and disrupting access to online services across Russia before the attack was filtered and neutralized.
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Arkansas Oral & Maxillofacial Surgeons
April 7, 2026
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[ ransomware, leak, healthcare ]
PEAR listed Arkansas Oral & Maxillofacial Surgeons in April 2026 and threatened to release allegedly stolen patient information. DataBreach.com later indexed 189,905 associated rows. The practice did not publicly confirm the actor's attribution or claimed scope, the access vector was not established, and no operational disruption was documented.
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Aitkin County Health and Human Services
April 7, 2026
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[ phishing, healthcare, government ]
Cybercriminals used phishing messages to obtain access to three Aitkin County Health and Human Services email accounts between April 7 and April 8, 2026. The attackers downloaded the contents of one employee mailbox, including a Minnesota Department of Human Services MnCHOICES report containing information on 82,384 individuals. Aitkin County and Minnesota DHS reported 83,114 affected individuals in total. The actors and motive were not identified.
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Arkansas Oral & Maxillofacial Surgeons
April 7, 2026
Arkansas Oral & Maxillofacial Surgeons detected unauthorized access to its network on April 7, 2026. Its investigation later confirmed that an unauthorized party acquired patient files; Pear claimed the incident and reportedly posted stolen data to its leak site.
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LHC Group
April 7, 2026
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[ social, phishing, healthcare ]
Louisiana home health provider LHC Group said a hacker used credentials stolen by phoning an employee to access patient files on a vendor platform from 7-15 Apr 2026. Notices went to 28,000+ people in Sep 2026; the FBI was contacted.
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Apple American Group LLC and Apple American Group II, LLC
April 8, 2026
An unknown actor accessed Apple American Group servers between April 8 and April 9, 2026 and accessed or acquired files containing employee information. Washington regulatory data characterizes the incident as ransomware involving encrypted data.
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Undisclosed organizations
April 8, 2026
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[ ransomware, technology, social ]
Russian-speaking Aurora ransomware operators tricked the Cursor AI coding agent into aiding credential theft and intrusions at 7 to 20+ unnamed organizations from April 2026, per Reuters and CloudSEK; four victims later appeared on Aurora's leak site.