Millennium Partners Discloses Data Breach Impacting Customers and Employees
New York-based real estate firm Millennium Partners (formerly Millennium Partners Management LLC) reported a data breach affecting the personal information of customers and employees. The incident was detected on April 27, 2026, after an unauthorized party accessed the company’s systems between April 24 and April 26, 2026, causing a network disruption.
The ransomware group The Gentlemen claimed responsibility for the attack, announcing on May 5, 2026, via the dark web that they had exfiltrated data and threatened to publish it within eight to nine days. By July 9, 2026, Millennium Partners confirmed that sensitive data potentially including Social Security numbers had been accessed and acquired by the attackers.
In response, the company set up a toll-free call center (1-800-405-6108) through TransUnion, operating from 8 a.m. to 8 p.m. ET, Monday through Friday, to assist affected individuals. The breach underscores the ongoing risks of ransomware attacks targeting corporate networks and the exposure of sensitive personal data.
Source: https://www.claimdepot.com/data-breach/millennium-partners-2026
Millennium cybersecurity rating report: https://www.rankiteo.com/company/millennium-partners
"id": "MIL1790116475",
"linkid": "millennium-partners",
"type": "Ransomware",
"date": "4/2026",
"severity": "100",
"impact": "4",
"explanation": "Attack with significant impact with customers data leaks"{'affected_entities': [{'customers_affected': 'Customers and employees',
'industry': 'Real Estate',
'location': 'New York, USA',
'name': 'Millennium Partners (Millennium Partners '
'Management LLC)',
'type': 'Real Estate Firm'}],
'customer_advisories': 'Toll-free call center assistance for affected '
'individuals',
'data_breach': {'data_exfiltration': 'Yes',
'personally_identifiable_information': 'Social Security '
'numbers',
'sensitivity_of_data': 'High',
'type_of_data_compromised': 'Personal information, Social '
'Security numbers'},
'date_detected': '2026-04-27',
'date_publicly_disclosed': '2026-07-09',
'description': 'New York-based real estate firm Millennium Partners reported '
'a data breach affecting the personal information of customers '
'and employees. The incident was detected after an '
'unauthorized party accessed the company’s systems, causing a '
'network disruption. The ransomware group The Gentlemen '
'claimed responsibility and threatened to publish exfiltrated '
'data. Sensitive data, including Social Security numbers, was '
'potentially accessed and acquired by the attackers.',
'impact': {'data_compromised': 'Personal information, Social Security numbers',
'identity_theft_risk': 'High',
'operational_impact': 'Network disruption',
'systems_affected': 'Corporate networks'},
'motivation': 'Data Exfiltration, Extortion',
'ransomware': {'data_exfiltration': 'Yes'},
'references': [{'source': 'Cyber Incident Report'}],
'response': {'communication_strategy': 'Toll-free call center '
'(1-800-405-6108), operating 8 a.m. to '
'8 p.m. ET, Monday through Friday',
'third_party_assistance': 'TransUnion (toll-free call center)'},
'threat_actor': 'The Gentlemen',
'title': 'Millennium Partners Data Breach Impacting Customers and Employees',
'type': 'Data Breach, Ransomware'}