MainStreet Bancshares reported a data breach where thieves stole data belonging to approximately 4.65 percent of its total customer base during an attack on a third-party provider. The attack was discovered in March, and by April 28, it was confirmed that customer data had been compromised. The bank has around 55,000 ATMs and six branches across Virginia and Washington DC, with over 1,000 businesses using its on-prem banking offering. The bank's technical infrastructure was not compromised, nor were any unauthorized transactions or monies transferred. The attack did not impact the bank's operations or finances. The bank activated its incident response process and ceased activity with the affected vendor.
Source: https://www.theregister.com/2025/06/02/mainstreet_bancshares_says_thirdparty_breach/
TPRM report: https://scoringcyber.rankiteo.com/company/mainstreet-bank
"id": "mai741060225",
"linkid": "mainstreet-bank",
"type": "Cyber Attack",
"date": "6/2025",
"severity": "85",
"impact": "4",
"explanation": "Attack with significant impact with customers data leaks"{'affected_entities': [{'customers_affected': '4.65% of total customer base',
'industry': 'Financial Services',
'location': 'Fairfax, VA',
'name': 'MainStreet Bancshares',
'size': '55,000 ATMs, 6 branches',
'type': 'Bank'}],
'attack_vector': 'Third-party Vendor',
'customer_advisories': 'May 26, 2025',
'data_breach': {'data_exfiltration': True,
'number_of_records_exposed': '4.65% of total customer base',
'type_of_data_compromised': 'Customer Data'},
'date_detected': 'March 2025',
'date_publicly_disclosed': 'May 2025',
'date_resolved': 'May 26, 2025',
'description': 'Thieves stole data belonging to some of MainStreet '
"Bancshares' customers during an attack on a third-party "
'provider.',
'impact': {'data_compromised': 'Customer Data'},
'investigation_status': 'Completed',
'post_incident_analysis': {'corrective_actions': 'Ceased all activity with '
'the affected provider'},
'references': [{'source': 'The Register'}],
'regulatory_compliance': {'regulatory_notifications': 'SEC Form 8-K filing'},
'response': {'communication_strategy': 'Notified impacted customers and '
'provided tools to monitor suspicious '
'activity',
'enhanced_monitoring': True,
'incident_response_plan_activated': True,
'recovery_measures': 'Established monitoring systems, notified '
'impacted customers',
'remediation_measures': 'Ceased all activity with the affected '
'provider'},
'stakeholder_advisories': 'SEC Form 8-K filing',
'title': 'Data Breach at MainStreet Bancshares',
'type': 'Data Breach'}