Understanding Data Exfiltration Prevention

In an economy where securing data can mean the difference between success and failure, implementing proven data exfiltration prevention strategies is more critical than ever. According to a study conducted by IBM, a data breach can cost global organizations an average of nearly $5 million per incident. In addition to the financial ramifications, data theft can lead to lower customer trust, a loss of future revenue, and even potential lawsuits.

Here, we’ll cover why data exfiltration prevention is so important, explain common exfiltration methods, and discuss how to detect data exfiltration and keep your information secured from external and internal threats.

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What is data exfiltration?

Data exfiltration, also known as data theft, is a term used to describe the process of stealing sensitive or confidential data from personal computers, corporate networks, or other systems.  Data exfiltration is a malicious act done with clear intent — usually for financial gain.

Threat actors rely on various tactics to gain access and steal data, including social engineering or brute force attacks. Every employee and access point is a potential vector for attack.

Organizations must take a vigilant approach to data security both on premises and across cloud infrastructure to prevent active intrusion attempts, as well as careless actions that may introduce vulnerabilities into secure networks. 

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What data are cyber attackers stealing?

The type of data that malicious actors are looking to steal often depends on their goals. Some examples include:

• Proprietary data, such as intellectual property, company secrets, source code, internal messaging, technical schematics, and anything else a malicious actor could use to gain intimate knowledge of an organization’s inner workings.
• Customer data, like personally identifiable information (including names, addresses, and social security numbers), licensing information, bank account and credit card numbers, biometric data, and medical records, which can then be sold or used in identity theft operations.
• Data that allows for further intrusion into secure systems, like login credentials or security details.

Once threat actors steal this information, they can take any number of actions with it, such as:

• extorting the organization with a ransom demand;
• auctioning data off on the black market;
• exposing stolen data to the public;
• or gaining leverage over other corporations or governments.

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Common data exfiltration techniques

Generally, data exfiltration threats can occur from two directions:

• externally, as malicious actors attempt to gain access to private networks from the outside;
• or internally, whether by accident (an employee leaves a USB drive with sensitive data unsupervised) or with malicious intent (a contractor uses their security clearance to gain direct access to network systems).

Threat actors may use the following methods to access and steal sensitive data:

• Phishing: Social engineering attacks via phishing messages are one of the common ways cyber attackers attempt to gain access to secure systems. They are also one of the most successful — a recent study by CISA found that 8 in 10 organizations had at least one user succumb to a simulated attack. These messages often appear legitimate, mimicking third-party website messaging to convince users to click on a desired link that can steal login credentials or force malware downloads.
• Outbound emails: Social engineering can influence users to send sensitive data via email as file attachments, or malicious actors can monitor outgoing email servers and attempt to steal this data as it is transmitted.
• Careless user activity: Actions such as using easy-to-guess passwords, leaving passwords exposed, leaving sensitive data on unsecured devices, or leaving devices unattended in public areas can all lead to a potential data breach.
• Misconfigurations: Poorly configured networks can expose sensitive data to the public — like when Microsoft AI researchers accidentally misconfigured GitHub user permissions and exposed 38 TB of sensitive customer data.

Once malicious actors have access, they’ll often rely on the following data exfiltration examples to transmit the information out of the secured network:

• Limited data transfer: Malicious actors may limit file transfer sizes and spread them throughout the day to exfiltrate larger files without triggering security alerts.
• Scheduled data transfer: Scheduling data transfers during the workday can help data exfiltration attempts blend in with normal operations.
• Using alternate networks or transmission methods: Some threat actors may rely on Wi-Fi, mobile hotspots, and even Bluetooth connections to transfer data.
• Physical devices: Many external USB drives are small and easily pocketable, making them discreet methods for plugging into physical endpoints and transferring data.
• Via the cloud: Some data thieves may use cloud services to upload stolen data to an external server.

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Data exfiltration prevention methods

Create a data loss prevention policy

If you’re wondering how to prevent data exfiltration attempts before they happen, a robust data loss prevention (DLP) policy is a solid first step. This policy will provide your organization with a framework of technology implementations and processes to keep tabs on data across your entire network, monitor it for any unauthorized activity, and protect it against exfiltration attempts. It will also help align your organization’s security stance with security and privacy compliance requirements, like HIPAA, PCI DSS, and GDPR. Take time to develop policies that also protect endpoints and cloud infrastructure for a holistic approach to data security.

Utilize least-privilege access

Use role-based access controls to limit access to sensitive data. By limiting employee access to only the data and systems they need to do their jobs, system administrators can reduce the possibility of social engineering or user error exposing this data to exfiltration attempts. Further secure user access to proprietary data with multi-factor authentication and continuous monitoring systems that track user activity and flag suspicious behavior.

Fortify employee knowledge with security training

Users are often the first line of defense against data exfiltration attempts. In fact, one study found that human error is responsible for nearly 90% of all data breaches. Annual training sessions will help keep data security top of mind for your employees and build a security-forward foundation throughout the organization. Regular updates on the latest intrusion methods and reminders on how to confirm phishing attempts will also reinforce those data security practices between formal training sessions. 

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Build a unified security approach

Threat actors are continuously evolving their techniques to steal data. An effective data exfiltration prevention strategy takes a holistic approach, examining infrastructural vulnerabilities, monitoring endpoints, and managing user activity to protect against current and new threats. 

Lookout can help you build that strategy. Register for the free Lookout SSE Hands-on Labs today and learn how to keep your sensitive information secure at-rest and in-motion with a unified data protection strategy.