Introduction
As a security professional, protecting your organization’s network and data from insider threats is a critical responsibility. Insider threats refer to risks posed by malicious or negligent actions from people within your organization, such as employees, contractors, or business partners. These individuals often have authorized access to sensitive systems and confidential information, making the threat hard to detect and mitigate. However, with the right strategies and security controls, you can effectively minimize the risk of insider attacks.
Understanding the Insider Threat Landscape
To secure your network, you first need to understand the scope and nature of insider threats. Common insider attacks include:
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Data theft – Insiders stealing proprietary information for financial gain or to benefit another organization. This could involve copying files to a USB drive, emailing data externally, or uploading to a cloud application.
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Fraud – Insiders falsifying data or transactions for personal profit. Examples are submitting fake invoices or tampering with financial systems.
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Sabotage – Disgruntled insiders destroying data, deleting files, or performing other malicious activities to damage the organization.
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Espionage – Working with external parties to steal confidential data and trade secrets. This is a particular concern when employees leave to competitors.
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Unintentional insider threats – Well-meaning employees causing breaches through account misuse, falling for phishing scams, or mishandling data.
Understanding insider attack motivations, from greed and revenge to accidental mistakes, helps you focus your defenses accordingly.
Key Strategies for Securing Your Network
Here are some best practices for securing your network and systems against insider attacks:
Implement Least Privilege Access
Only provide users with the minimum access required to do their jobs. This reduces opportunities for insiders to access unauthorized data or systems. Some tips:
- Implement role-based access controls and segregate duties
- Disable unnecessary administrative accounts
- Carefully monitor privileged access
Enforce Separation of Duties
Divide tasks between multiple people to introduce checks and balances. For example, separate the ability to create a vendor account from the ability to approve payments. This ensures no single person controls an entire process.
Monitor User Activity
Detecting suspicious insider behavior early is crucial. Solutions like user behavior analytics (UBA) can identify anomalies and high-risk activities. Focus on monitoring privileged users and systems containing sensitive data.
Control Data Access
Implement controls around accessing and sharing confidential data:
- Data loss prevention (DLP) tools to detect potential data exfiltration
- Access controls and encryption for sensitive systems and files
- Policies disabling external storage devices
- Limiting access to only specific business needs
Prioritize System Logging and Monitoring
Comprehensive logging from servers, endpoints, and network devices provides visibility into insider actions. Send logs to a centralized security information and event management (SIEM) system for real-time monitoring and analysis.
Provide Security Awareness Training
Educate all employees on security best practices and how to spot potential insider threats. Training can help prevent unintentional data leaks.
Implement Strict Offboarding Procedures
Insider threats often arise when employees leave or are terminated. Be sure to immediately revoke system access and remind departing employees about confidentiality agreements.
Technical Controls to Prevent Insider Attacks
In addition to the above strategies, some technical controls can help thwart insider threats:
Deploy Data Loss Prevention Tools
DLP tools use deep content inspection and policies to detect potential data exfiltration over email, web channels, and endpoint actions. They can block confidential data from leaving the network.
Implement User and Entity Behavior Analytics
UEBA solutions apply machine learning and statistical modeling to recognize anomalous user activities that could signal malicious intent. UEBA can identify insider threat behaviors across the IT environment.
Use Cloud Access Security Brokers
CASBs secure cloud usage by adding visibility and access controls. Features like user behavior monitoring, encryption, and contextual access policies minimize cloud data theft.
Enable Strong Authentication
Require multi-factor authentication for access to critical systems and data. This adds an extra barrier for unauthorized access if a password is compromised.
Protect Critical Infrastructure
Extra safeguards for crown jewel assets include privileged access management (PAM) tools to control admin access and database activity monitoring (DAM) to monitor database queries.
Fostering a Positive Security Culture
The most effective defense combines people, processes, and technology. Beyond technical controls, emphasizing security awareness and promoting collaboration will strengthen resilience against insider threats. Consider steps like:
- Sponsoring security training for all staff
- Encouraging peer monitoring and a speak-up culture
- Including security in performance reviews
- Evangelizing security best practices
- Developing clear and enforceable security policies
- Maintaining open communications with employees
A holistic approach to insider threat defense, backed by management support and engagement from across the organization, will help provide comprehensive protection for your business-critical systems and data.
Conclusion
Left unchecked, insider threats pose a serious risk to organizations through data theft, fraud, and sabotage. Mitigating this requires controlling access, monitoring activity, securing data, and promoting secure staff behaviors. Technical controls like UEBA and DLP combined with strong security policies and processes give organizations layered protection against malicious and negligent insider actions. Securing networks and cultivating a positive security culture together provide robust defenses to this menace.
