[{"data":1,"prerenderedAt":137},["ShallowReactive",2],{"article-slug-bank3-discloses-data-breach-after-qilin-ransomware-claim":3,"articles-index":-1},{"id":4,"slug":5,"headline":6,"title":7,"summary":8,"full_report":9,"twitter_post":10,"meta_description":11,"category":12,"severity":16,"entities":17,"cves":30,"sources":31,"events":48,"mitre_techniques":61,"mitre_mitigations":78,"d3fend_countermeasures":106,"iocs":107,"cyber_observables":108,"tags":125,"extract_datetime":128,"article_type":129,"impact_scope":130,"pub_date":35,"reading_time_minutes":136,"createdAt":128,"updatedAt":128},"890a0b41-44d5-4364-ae08-0ed134b45cfe","bank3-discloses-data-breach-after-qilin-ransomware-claim","Bank3 Discloses Data Breach, Exposing Customer SSNs and Financial Data","Bank3 Notifies Customers of Data Breach After Qilin Ransomware Group's Claims","Bank3, a Tennessee-based community bank, has started notifying customers of a data breach that exposed highly sensitive personal and financial information, including Social Security numbers and financial account details. The notification follows claims made in late 2025 by the Qilin ransomware group, which alleged it had stolen 149 GB of data, representing the bank's 'entire data set.' The breach occurred between July and August 2025.","## Executive Summary\n**Bank3**, a community bank based in Memphis, Tennessee, has officially disclosed a data breach that compromised the sensitive information of its clients. The bank's notification to the Maine Attorney General on April 15, 2026, confirms that an unauthorized actor had access to its network for several weeks between July and August 2025. This disclosure follows a public claim by the notorious **[Qilin](https://malpedia.caad.fkie.fraunhofer.de/actor/qilin)** ransomware group in October 2025, which asserted it had exfiltrated 149 GB of data. The compromised information includes names, Social Security numbers, financial account numbers, and payment card details, placing affected individuals at significant risk of identity theft and financial fraud.\n\n---\n\n## Threat Overview\nThe incident is a classic double-extortion ransomware attack perpetrated by the **[Qilin](https://malpedia.caad.fkie.fraunhofer.de/actor/qilin)** group, one of the most active ransomware operators. The attack timeline reveals a significant dwell time, allowing the threat actors to thoroughly explore the network and exfiltrate a large volume of data before being detected.\n\n-   **Breach Period:** July 25, 2025 – August 7, 2025\n-   **Detection:** August 20, 2025\n-   **Public Extortion:** October 13, 2025 (Qilin posts claim on its dark web leak site)\n-   **Public Disclosure:** April 15, 2026\n\n## Technical Analysis\nWhile **Bank3** has not detailed the initial access vector, **[Qilin](https://malpedia.caad.fkie.fraunhofer.de/actor/qilin)** is known to leverage common ransomware TTPs:\n1.  **Initial Access:** Often gained through phishing campaigns ([`T1566`](https://attack.mitre.org/techniques/T1566/)) or by exploiting vulnerabilities in public-facing infrastructure like VPNs ([`T1190`](https://attack.mitre.org/techniques/T1190/)).\n2.  **Discovery and Lateral Movement:** Once inside, the group uses tools like **[Cobalt Strike](https://attack.mitre.org/software/S0154/)** to map the internal network, escalate privileges, and move towards high-value targets like domain controllers and file servers.\n3.  **Data Exfiltration ([`T1048`](https://attack.mitre.org/techniques/T1048/)):** Before deploying the encryptor, the group exfiltrates large volumes of sensitive data to be used as leverage in their extortion demands. The claim of 149 GB of data suggests a successful and prolonged exfiltration phase.\n4.  **Impact ([`T1486`](https://attack.mitre.org/techniques/T1486/)):** The final stage involves deploying the ransomware payload to encrypt files across the network, causing significant operational disruption.\n\n## Impact Assessment\nThe compromised data is highly sensitive and puts affected customers at severe risk. The stolen information includes:\n-   Names and Dates of Birth\n-   Social Security Numbers (SSNs)\n-   Taxpayer Identification Numbers\n-   Driver's License Numbers\n-   Financial Account and Payment Card Information\n-   Health Insurance Information\n\nThis data can be used for a wide range of fraudulent activities, including opening new lines of credit, filing fraudulent tax returns, and committing identity theft. **Bank3** is offering 12 months of credit monitoring services to affected individuals, but the lifetime risk associated with a stolen SSN is permanent.\n\n## IOCs\nNo Indicators of Compromise (IOCs) have been publicly released by **Bank3**.\n\n## Detection & Response\nDetecting groups like **[Qilin](https://malpedia.caad.fkie.fraunhofer.de/actor/qilin)** requires a focus on behavioral indicators:\n1.  **C2 Beaconing:** Monitor for network traffic consistent with C2 frameworks like **[Cobalt Strike](https://attack.mitre.org/software/S0154/)**. This includes regular, timed beacons to external IP addresses over common ports (80, 443). (D3-NTA: Network Traffic Analysis)\n2.  **Credential Access:** Monitor for signs of credential theft, such as process memory dumping of `lsass.exe` or Kerberoasting attacks (Event ID 4769). (D3-DAM: Domain Account Monitoring)\n3.  **Data Staging:** Look for the creation of large archive files (`.zip`, `.rar`) on servers, which often precedes data exfiltration.\n\n## Mitigation\n1.  **Multi-Factor Authentication (M1032):** Enforce MFA across all remote access points (VPN, RDP) and for all administrative accounts. This is one of the most effective controls against ransomware attacks that rely on compromised credentials.\n2.  **Network Segmentation (M1030):** A well-segmented network can prevent attackers from moving from a compromised workstation to critical servers, containing the breach to a smaller area.\n3.  **Immutable Backups:** Maintain offline and immutable backups of critical data. This ensures that even if the primary network is encrypted, data can be restored without paying a ransom.\n4.  **Endpoint Detection and Response (EDR):** Deploy a modern EDR solution capable of detecting and blocking malicious behaviors associated with ransomware, such as suspicious process chains and attempts to disable security tools.","Bank3 discloses data breach exposing customer SSNs & financial data. 🏦 The notice follows claims by the Qilin ransomware group to have stolen 149GB of data from the Tennessee bank. #DataBreach #Ransomware #Qilin #Finance","Tennessee-based Bank3 has disclosed a data breach exposing customer Social Security numbers and financial data, following a claim by the Qilin ransomware group in late 2025.",[13,14,15],"Data Breach","Ransomware","Threat Actor","high",[18,21,25,28],{"name":19,"type":20},"Bank3","company",{"name":22,"type":23,"url":24},"Qilin","threat_actor","https://malpedia.caad.fkie.fraunhofer.de/actor/qilin",{"name":14,"type":26,"url":27},"malware","https://en.wikipedia.org/wiki/Ransomware",{"name":29,"type":20},"TransUnion",[],[32,37,43],{"url":33,"title":34,"date":35,"website":36},"https://claimdepot.org/data-breach/bank3-data-breach-exposes-clients-ssns-and-financial-information/","Bank3 Data Breach Exposes Clients' SSNs and Financial Information","2026-04-16","claimdepot.org",{"url":38,"title":39,"date":40,"friendly_name":41,"website":42},"https://www.fortinet.com/fortiguard/threat-intelligence/threat-research-briefs/qilin-ransomware","Qilin Ransomware - Threat Actor","2026-04-15","Fortinet","fortinet.com",{"url":44,"title":45,"date":35,"friendly_name":46,"website":47},"https://www.blackfog.com/the-state-of-ransomware-2026/","The State Of Ransomware 2026","BlackFog","blackfog.com",[49,52,55,58],{"datetime":50,"summary":51},"2025-07-25T00:00:00Z","Start of the period during which the attacker had access to Bank3's network.",{"datetime":53,"summary":54},"2025-08-20T00:00:00Z","Bank3 becomes aware of suspicious activity on its network.",{"datetime":56,"summary":57},"2025-10-13T00:00:00Z","The Qilin ransomware group claims responsibility for the attack on its dark web leak site.",{"datetime":59,"summary":60},"2026-04-15T00:00:00Z","Bank3 begins sending data breach notifications to affected customers.",[62,66,70,74],{"id":63,"name":64,"tactic":65},"T1486","Data Encrypted for Impact","Impact",{"id":67,"name":68,"tactic":69},"T1048","Exfiltration Over Alternative Protocol","Exfiltration",{"id":71,"name":72,"tactic":73},"T1190","Exploit Public-Facing Application","Initial Access",{"id":75,"name":76,"tactic":77},"T1003.001","LSASS Memory","Credential Access",[79,88,97],{"id":80,"name":81,"d3fend_techniques":82,"description":86,"domain":87},"M1032","Multi-factor Authentication",[83],{"id":84,"name":81,"url":85},"D3-MFA","https://d3fend.mitre.org/technique/d3f:Multi-factorAuthentication","Enforcing MFA on VPNs and administrative accounts is a critical defense against attacks leveraging stolen credentials.","enterprise",{"id":89,"name":90,"d3fend_techniques":91,"description":96,"domain":87},"M1030","Network Segmentation",[92],{"id":93,"name":94,"url":95},"D3-NI","Network Isolation","https://d3fend.mitre.org/technique/d3f:NetworkIsolation","Segmenting the network can prevent ransomware from spreading from an initial entry point to critical financial systems and data stores.",{"id":98,"name":99,"d3fend_techniques":100,"description":105,"domain":87},"M1047","Audit",[101],{"id":102,"name":103,"url":104},"D3-DAM","Domain Account Monitoring","https://d3fend.mitre.org/technique/d3f:DomainAccountMonitoring","Auditing and monitoring for unusual account behavior, such as credential dumping attempts or anomalous service ticket requests, can help detect attackers before they deploy ransomware.",[],[],[109,114,120],{"type":110,"value":111,"description":112,"context":113,"confidence":16},"process_name","lsass.exe","Ransomware groups frequently attempt to dump memory from the LSASS process to steal credentials. Any process other than trusted system processes accessing lsass.exe is highly suspicious.","EDR, Windows Security Event Logs.",{"type":115,"value":116,"description":117,"context":118,"confidence":119},"event_id","4769","Windows Event ID 4769 (A Kerberos service ticket was requested) with a service name ending in '$' and a non-machine account name can indicate a Kerberoasting attack.","Domain Controller Security Logs, SIEM.","medium",{"type":121,"value":122,"description":123,"context":124,"confidence":16},"network_traffic_pattern","Large, sustained uploads from internal servers to external cloud storage IPs.","A strong indicator of data exfiltration, which is a precursor to double-extortion ransomware attacks.","Firewall logs, Netflow data.",[13,14,22,19,126,127],"Finance","SSN","2026-04-16T15:00:00.000Z","NewsArticle",{"geographic_scope":131,"countries_affected":132,"industries_affected":134,"people_affected_estimate":135},"local",[133],"United States",[126],"Undisclosed number of bank customers",4,1776358243853]