Thialf: Thialf ice skating stadium hit by ransomware attack

Cyberattack Targets Thialf Ice Skating Stadium in Heerenveen

The Thialf ice skating stadium in Heerenveen, Netherlands, has been hit by a ransomware attack, with cybercriminals demanding payment in exchange for restoring access to its systems and preventing the release of stolen data. The incident was confirmed by Thialf to RTL Nieuws, though the organization declined to provide further details, citing ongoing discussions with the attackers.

The hackers claim to have exfiltrated internal documents, employee information, financial contracts, and other sensitive data. The ransom amount remains undisclosed. The attack has been attributed to The Gentlemen, a relatively new but highly skilled cybercriminal group that emerged in mid-2023. Microsoft previously warned about the group’s proficiency in network infiltration and system lockdowns.

Thialf is the eighth Dutch victim of The Gentlemen, following attacks on organizations such as the Institute for the Dutch Language and a major construction firm. Despite the breach, Thialf stated that its scheduled events, including the 2030 Olympic long-track speed skating competitions the first Winter Games events to be held in the Netherlands will proceed as planned. The full impact of the attack on the stadium’s operations remains unclear.

Source: https://nltimes.nl/2026/07/24/thialf-ice-skating-stadium-hit-ransomware-attack

Thialf BV cybersecurity rating report: https://www.rankiteo.com/company/thialf-bv

"id": "THI1784903911",
"linkid": "thialf-bv",
"type": "Ransomware",
"date": "6/2026",
"severity": "100",
"impact": "5",
"explanation": "Attack threatening the organization's existence"

{'affected_entities': [{'industry': 'Sports/Entertainment',
                        'location': 'Heerenveen, Netherlands',
                        'name': 'Thialf',
                        'type': 'Stadium'}],
 'data_breach': {'data_exfiltration': 'Yes',
                 'personally_identifiable_information': 'Employee information',
                 'sensitivity_of_data': 'High',
                 'type_of_data_compromised': 'Internal documents, employee '
                                             'information, financial '
                                             'contracts, and other sensitive '
                                             'data'},
 'description': 'The Thialf ice skating stadium in Heerenveen, Netherlands, '
                'has been hit by a ransomware attack, with cybercriminals '
                'demanding payment in exchange for restoring access to its '
                'systems and preventing the release of stolen data. The '
                'hackers claim to have exfiltrated internal documents, '
                'employee information, financial contracts, and other '
                'sensitive data.',
 'impact': {'data_compromised': 'Internal documents, employee information, '
                                'financial contracts, and other sensitive data',
            'operational_impact': 'Full impact on operations remains unclear, '
                                  'but scheduled events will proceed as '
                                  'planned'},
 'investigation_status': 'Ongoing',
 'motivation': 'Financial gain',
 'ransomware': {'data_encryption': 'Yes', 'data_exfiltration': 'Yes'},
 'references': [{'source': 'RTL Nieuws'}],
 'response': {'communication_strategy': 'Declined to provide further details '
                                        'citing ongoing discussions with '
                                        'attackers'},
 'threat_actor': 'The Gentlemen',
 'title': 'Ransomware Attack on Thialf Ice Skating Stadium',
 'type': 'Ransomware'}