How to Prevent Data Leaks from Departing Employees

By | March 20, 2025

When an employee leaves a company, the focus often centers on logistical and HR-related tasks—final paychecks, exit interviews, and the return of company property. However, a critical aspect that frequently goes overlooked is securing sensitive business data to prevent leaks from departing employees.

Employee departures, whether voluntary or involuntary, pose significant cybersecurity risks. The 2024 Verizon Data Breach Investigations Report (DBIR) analyzed a record high of 30,458 security incidents, of which 10,626 were confirmed data breaches, affecting organizations across 94 countries.

Notably, the report highlights that 68% of breaches involve a non-malicious human element, such as errors or social engineering attacks. This statistic spotlights the vulnerability organizations face when proper offboarding procedures are not meticulously followed.

For small and medium-sized businesses (SMBs), the risk is particularly pronounced. Limited resources and the absence of dedicated IT security teams can lead to inadequate offboarding processes, increasing the likelihood that former employees retain access to sensitive information long after their departure.

This oversight can result in the theft of intellectual property, exposure of confidential customer data, or even deliberate sabotage.

Securing business data during the offboarding process is not merely about protecting assets; it’s about safeguarding the company’s future. This article outlines key strategies businesses should implement, including access control measures, secure offboarding procedures, backup policies, and threat monitoring.

By adopting a comprehensive approach, businesses can minimize the risks associated with departing employees and maintain a robust cybersecurity posture.

The Cybersecurity Risks of Employee Offboarding

When employees leave an organization, their departure can create security gaps that, if not properly managed, expose businesses to cyber threats. While external attacks from hackers and cybercriminals often dominate security discussions, insider threats—especially those involving former employees—can be just as damaging.

The 2024 Verizon Data Breach Investigations Report found that insider threats, including ex-employees who retain unauthorized access, contribute significantly to data breaches.

Whether through malicious intent (such as data theft for competitive advantage) or negligence (such as failing to return company devices), former employees can pose a serious risk to an organization’s data security.

Common Threats and Data Breaches from Ex-Employees

1. Unauthorized Access to Systems and Accounts
   When businesses fail to promptly revoke credentials, former employees may still have access to email accounts, cloud storage, customer databases, and financial systems. Even if their intentions are not malicious, their access creates a security liability that can be exploited by cybercriminals.
   
   
2. Theft of Intellectual Property and Sensitive Data
   Employees who move to competitors or start their own businesses may attempt to take proprietary data, customer lists, or trade secrets with them. In some cases, this can lead to legal disputes and compliance violations.
   
   
3. Deliberate Sabotage
   Disgruntled employees who feel wronged by their former employer may engage in destructive behaviors, such as deleting critical files, planting malware, or sharing sensitive company information online.
   
   
4. Weak Device and BYOD Policies
   Many companies operate in bring-your-own-device (BYOD) environments where employees use personal smartphones, tablets, or laptops for work. Without strong security policies, former employees may retain access to company emails, shared files, or messaging apps long after they leave.
   
   
5. Social Engineering Risks
   Cybercriminals often target ex-employees to gain access to an organization’s systems. Attackers may impersonate former employees in phishing scams or manipulate them into disclosing credentials. If a company does not properly deactivate accounts, attackers can exploit them for unauthorized access.

Why SMBs are Particularly Vulnerable

Small and medium-sized businesses are often at greater risk because they lack dedicated IT security teams and may not have structured offboarding procedures in place. Many SMBs rely on manual processes to revoke access, which increases the likelihood of oversight. Many organizations underestimate insider threats, leaving their systems exposed to risks that could have been mitigated with better policies.

A secure employee offboarding process must be a core part of any cybersecurity strategy, ensuring that departing employees do not leave security gaps behind.

Implementing Strong Access Control Measures

A well-defined access control strategy is the first line of defense against data leaks from departing employees. Without proper controls in place, former employees can retain unauthorized access to critical business systems, exposing the organization to security risks.

By implementing role-based access control (RBAC), multi-factor authentication (MFA), and regular access audits, businesses can significantly reduce the chances of an insider threat.

The Principle of Least Privilege (PoLP)

The principle of least privilege (PoLP) ensures that employees have access only to the data and systems necessary for their specific roles. This minimizes the risk of excessive permissions, where employees accumulate access to multiple systems over time without needing it.

Key steps to enforce PoLP include:

• Assigning access based on job function rather than individual requests.

• Periodically reviewing and revoking unnecessary privileges.

• Restricting administrative rights to essential personnel only.

By enforcing least privilege access, businesses can ensure that even if an employee attempts to misuse their credentials before leaving, their impact is minimized.

Revoking Access Immediately Upon Departure

One of the most common cybersecurity risks of employee offboarding is a delay in revoking access to corporate accounts and systems. This gap gives former employees a window of opportunity to access sensitive data or disrupt operations. A structured access revocation checklist should include:

• Deactivating accounts across all platforms, including email, cloud storage, SaaS applications, and internal systems.

• Revoking VPN and remote access privileges to prevent unauthorized logins.

• Collecting and wiping company devices before departure to remove sensitive data.

• Resetting shared credentials for any systems where employees had access.

According to NIST Special Publication 800-53, access revocation should be immediate and automated whenever possible to prevent delays and human error.

Strengthen with thirtyone3 technology’s Expertise

At thirtyone3 technology, we take a proactive approach to automated access revocation by integrating zero-trust security principles into our clients’ workflows. Our strategy ensures that access is revoked immediately upon termination or role changes, minimizing security risks.

We work closely with HR and IT teams to automate offboarding processes, enforce least privilege access, and maintain a strict audit trail for compliance. By implementing a zero-trust model, we verify every access request, continuously monitor permissions, and eliminate lingering access gaps.

Best Practices

• Automated Access Revocation – Instantly disable user accounts, email, and system access upon offboarding.

• Zero-Trust Security Model – Enforce least privilege access and continuous authentication to prevent unauthorized access.

• HR & IT Alignment – Integrate automation with HR systems for real-time role and status updates.

• Audit & Compliance Readiness – Maintain detailed logs for regulatory compliance and security audits.

By combining access control best practices with automation, businesses can eliminate one of the most significant IT security risks of employee offboarding. The next section will focus on creating a secure and structured offboarding process to prevent security gaps.

Backup Policies to Safeguard Critical Business Data

A well-structured data backup policy is essential for protecting business data from ex-employees. When employees leave, either voluntarily or involuntarily, there is always a risk of data loss, intentional deletion, or theft.

Without proper backup and recovery strategies, businesses may find themselves unable to restore lost information, leading to operational disruptions and compliance risks.

Why Backups are Critical During Employee Offboarding

Employees often have access to company files, customer records, and internal documentation. If this data is not properly backed up before their departure, businesses may experience:

• Intentional Data Deletion – Disgruntled employees may delete critical files before leaving as an act of retaliation.

• Accidental Data Loss – If an account is permanently deleted too soon, important files may be lost.

• Unauthorized Copies of Data – Employees may download or transfer sensitive company data before their access is revoked.

By maintaining secure, up-to-date backups, businesses can ensure they retain full control over their data, even if an employee tries to alter or remove files before leaving.

Best Practices for Backup and Data Protection

Automate Regular Backups

1. Use daily or real-time backups for critical business data.
2. Store backups in multiple locations (on-premises and cloud-based).

Use Version Control for Files

1. Implement file versioning so previous copies of documents can be restored if unauthorized changes are made.
2. Maintain audit logs to track file modifications before an employee departs.

Encrypt and Restrict Backup Access

1. Ensure only authorized personnel can access backup data.
2. Encrypt sensitive backups to protect against unauthorized retrieval.

Monitor for Unusual Download Activity

1. Watch for large file transfers before an employee leaves, which may indicate data exfiltration.
2. Use endpoint detection tools to flag suspicious activity.

Retain Backup Data for a Defined Period

1. Set clear data retention policies for former employee accounts.
2. Maintain backups of employee emails and project files for a period that aligns with compliance regulations.

Backup policies act as a safety net, ensuring that threats and data breaches from ex-employees do not compromise critical business operations. In the next section, we will discuss how monitoring tools and proactive security measures can help prevent insider threats before they occur.

Monitoring and Preventing Insider Threats Before They Happen

Preventing data leaks from departing employees isn’t just about revoking access after they leave—it also requires proactive monitoring before, during, and after the offboarding process. Many insider threats can be detected early if businesses know what to look for.

Identifying Behavioral Red Flags

Before an employee leaves, certain behaviors may indicate a heightened risk of data theft or security breaches. Some warning signs include:

• Unusual file access or transfers – Downloading large volumes of data, especially outside normal job responsibilities.

• Increased use of personal storage devices – Transferring files to USB drives, external hard drives, or personal cloud storage.

• Frequent access to sensitive documents – Viewing confidential files that are unrelated to current work tasks.

• Attempting to disable security controls – Turning off endpoint protection software or trying to bypass monitoring systems.

• Tense relationships with management – Employees who feel wronged by their employer may be more likely to engage in retaliatory behavior.

By tracking these early warning signs, businesses can proactively prevent data leaks before an employee leaves.

Using Endpoint Detection and Monitoring Solutions

Modern endpoint detection and response (EDR) tools help businesses monitor real-time user activity and flag suspicious behaviors before a data breach occurs. Effective monitoring should include:

• File activity tracking – Detecting unauthorized downloads, modifications, or deletions of sensitive files.

• Unusual login patterns – Monitoring remote access attempts or multiple failed login attempts on deactivated accounts.

• Shadow IT detection – Identifying employees who use unapproved apps or file-sharing services to store company data.

• Geolocation and device monitoring – Flagging login attempts from unusual locations or unrecognized devices.

Educating Employees on Cybersecurity Responsibilities

A well-informed workforce is the first line of defense against IT security risks of employee offboarding. Regular cybersecurity awareness training should include:

• Company policies on data access and security – Employees must understand what data they can and cannot take with them.

• The consequences of data theft – Many employees don’t realize that taking company data is illegal and can lead to legal action.

• Secure data handling best practices – Reinforce the importance of encrypted storage, strong passwords, and reporting suspicious activity.

By integrating proactive monitoring and employee education, businesses can mitigate cybersecurity risks of employee offboarding before they turn into costly security incidents. In the next section, we will explore how IT security solutions can further reduce offboarding risks.

Leveraging IT Security Solutions to Reduce Risk

Implementing the right IT security solutions can significantly reduce the risk of data leaks during employee offboarding. Many businesses rely on manual processes to revoke access, monitor insider threats, and secure company data, but automation and advanced security tools can streamline these efforts and ensure nothing is overlooked.

How Automation Can Streamline Secure Offboarding

Manual offboarding processes are prone to errors, leading to security gaps that ex-employees can exploit. Automated identity and access management (IAM) solutions ensure that access revocation happens instantly when an employee leaves.

Key security solutions for offboarding automation include:

• Identity and Access Management (IAM) Platforms – Automates user provisioning and deprovisioning to ensure that employees lose access across all systems simultaneously.

• Single Sign-On (SSO) and Multi-Factor Authentication (MFA) – Prevents unauthorized logins by requiring extra verification.

• Automated Data Loss Prevention (DLP) Tools – Monitors and blocks attempts to copy or transfer sensitive data.

• Endpoint Protection and Monitoring – Detects suspicious behavior and prevents unauthorized device access.

By leveraging IT security solutions, businesses can ensure a secure employee offboarding process without relying solely on manual intervention.

The Role of Managed Security Services in Offboarding

For businesses without dedicated cybersecurity teams, managed security service providers (MSSPs) can help implement and oversee secure offboarding policies. MSSPs provide:

• 24/7 monitoring for insider threats and unauthorized access attempts.

• Automated security updates and patches to prevent vulnerabilities.

• Incident response and forensic investigations if a breach occurs.

Outsourcing security management allows businesses to focus on operations while ensuring their IT security remains up-to-date and compliant.

Final IT Offboarding Checklist

To protect business data from ex-employees, organizations should follow a comprehensive IT security offboarding checklist that includes:

• Immediately revoking access to all company systems, devices, and accounts.

• Monitoring unusual activity before and after an employee leaves.

• Backing up critical files before deactivating accounts.

• Using automated IAM tools to streamline access removal.

• Educating employees on security best practices to reduce insider threats.

Strengthen with thirtyone3 technology’s Expertise

thirtyone3 technology partnered with a large healthcare organization with over 500 users to implement an automated offboarding solution. By collaborating closely with their Human Resources department, we developed a system that seamlessly integrated with their existing processes and IT infrastructure.

This solution ensured immediate deactivation of accounts, improved security controls, and reduced administrative burden. The result was a streamlined offboarding process that enhanced system security, minimized risks, and strengthened compliance documentation.

Key Benefits:

• Closed Security Gaps – Automated deactivation of accounts and access rights upon employee departure.

• Streamlined Processes – Reduced manual work for HR and IT teams, ensuring faster offboarding.

• Enhanced Compliance – Provided a strong audit trail for regulatory and security compliance.

• Improved Physical Security – Ensured badge and facility access removal in alignment with digital offboarding.

• Optimized IT Security – Minimized the risk of unauthorized access and potential data breaches.

By integrating automated IT security solutions and managed security services, businesses can eliminate the risks of insider threats and ensure a seamless, secure transition when employees leave.

Strengthen Your Defense Against Insider Threats

Departing employees pose a significant security risk if businesses fail to implement a structured and secure offboarding process. From unauthorized access and data theft to accidental data loss, the cybersecurity risks of employee offboarding are too great to ignore.

Without proper controls in place, companies may face financial losses, compliance violations, and reputational damage.

By implementing access control policies, structured offboarding procedures, secure backup strategies, and proactive monitoring, organizations can prevent threats and data breaches from ex-employees before they occur.

The key to success lies in automation and continuous monitoring, ensuring that no access remains unchecked, and that any suspicious activity is detected early.

thirtyone3 technology helps businesses secure their offboarding process through automated access management, real-time monitoring, and managed security services.

Whether you need identity and access management (IAM) solutions, endpoint security, or a comprehensive offboarding security strategy, we provide the tools and expertise to safeguard your data and minimize IT security risks.

Don’t wait until an ex-employee becomes a security risk—take control of your offboarding process today. Contact thirtyone3 technology to learn how we can help you secure your business from insider threats.