Orphan accounts refer to user or non-human identities—such as former employees, contractors, service accounts, bots, APIs, and AI agents—that remain active and unmanaged across an organization's IT environment after their legitimate use has ended. These accounts persist due to fragmentation in identity and access management (IAM) systems, which typically focus on human users and require manual integration for each application. Many applications and non-human identities fall outside the scope of traditional IAM and identity governance and administration (IGA) tools, resulting in a shadow layer of untracked accounts with valid credentials and often elevated privileges. This creates significant security risks as attackers can exploit these dormant accounts as backdoors to gain unauthorized access. Real-world incidents, including the Colonial Pipeline ransomware attack and breaches involving ghost third-party vendor accounts, highlight the exploitation of orphan accounts. The complexity of ownership, turnover, mergers and acquisitions, and the rise of semi-autonomous AI agents further complicate governance. Orphan accounts also cause compliance violations (e.g., ISO 27001, NIS2, PCI DSS), inflate license costs, and slow incident response due to forensic blind spots. Effective mitigation involves continuous identity telemetry collection from both managed and unmanaged systems, correlating authentication and usage logs to verify account legitimacy, mapping roles and privileges based on actual usage, and automating the flagging or decommissioning of inactive or ownerless accounts. This approach transforms orphan accounts from invisible liabilities into manageable entities, enhancing security posture and compliance.

For European organizations, orphan accounts pose multifaceted risks. From a security perspective, these accounts provide attackers with stealthy entry points that bypass standard IAM controls, potentially leading to data breaches, ransomware infections, and lateral movement within networks. Compliance impact is significant, as regulations like NIS2 Directive, GDPR, and sector-specific standards (e.g., PCI DSS) mandate strict access controls and timely deprovisioning of accounts; failure to manage orphan accounts can result in regulatory penalties and reputational damage. Operationally, orphan accounts inflate software license usage and increase audit complexity, driving up costs and resource consumption. Incident response and forensic investigations are hampered by the presence of untracked identities, delaying breach detection and remediation. The growing use of AI-driven automation and cloud services in Europe exacerbates the challenge by increasing the number and complexity of non-human identities. Organizations undergoing mergers and acquisitions are particularly vulnerable due to legacy accounts and tokens persisting post-consolidation. Overall, the presence of orphan accounts undermines the principles of least privilege and zero trust, weakening the security posture of European enterprises.

European organizations should adopt a continuous identity audit strategy that provides full visibility into all identities, including human, non-human, and AI-driven accounts. This requires integrating telemetry collection directly from applications, cloud consoles, and unmanaged systems to capture authentication and usage data beyond traditional IAM scopes. Establish a unified audit trail that correlates joiner/mover/leaver events with real-time activity logs to verify account ownership and legitimacy. Implement role context mapping to understand actual privilege usage and detect privilege creep. Deploy automated enforcement mechanisms that flag or disable accounts with no recent activity or unclear ownership, reducing reliance on manual reviews. Incorporate identity governance solutions capable of managing non-human identities and AI agents, ensuring lifecycle management and accountability. Regularly perform post-M&A identity inventories to identify and remediate orphan accounts inherited from acquisitions. Enhance collaboration between IT, security, and HR teams to maintain accurate identity records. Finally, align identity management practices with compliance requirements such as NIS2 and GDPR, documenting deprovisioning processes and audit trails to demonstrate regulatory adherence.