Mitigating Data Exfiltration: Four Ways to Detect and Respond to Unauthorized Data Transfers

Data has come to be regarded as an invaluable currency, and protecting sensitive information from falling into the wrong hands is an urgent imperative for organizations. In fact, with the advent of cloud computing, one could say that cybersecurity has become an entire exercise in data security.

It is, therefore, concerning that most data security advice focuses on preventing intrusions and breaches while placing less emphasis on or misunderstanding data exfiltration, which can be just as dangerous.

Whether malicious or unintentional, data exfiltration is a challenge to be addressed and this article shows you four ways to do just that and protect your organization from harm.

Types of Data Exfiltration Events

Data exfiltration occurs in various forms, some of which are considered below:

• Social engineering and phishing attacks: because of the smart manipulation that takes place via social engineering, phishing attacks are among the easiest to attack people and organizations with. In 2022, there were over 500 million recorded phishing attacks, more than double the figures for 2021.
• Human error and procedural issues: recently, a forensic deficiency was determined to be the cause of a security issue with Google Workspace that caused invisible data exfiltration.
• Poor permissions policy: most data exfiltration attacks can be mitigated by having appropriate permissions set in the first place. Normally, employees should not have access to more data than they need to perform their functions at every given time, and each person must be trained on appropriate security procedures for their permission level.
• Outbound emails: emails are a treasure trove of information for attackers because they contain sensitive company instructions, calendar schedules, business forecasts, critical documents and other resources, as well as source codes, among others. Sending sensitive documents over email to untrusted parties, without encryption in place is a common cause of data exfiltration.
• Data transmission to unauthorized devices: This can happen in either of two ways: via unauthorized downloads to insecure devices, or by uploads to external devices. Either way, there must be an unauthorized device involved, and if the data is stored on the cloud, it must first be downloaded before it can be compromised.
• Ransomware: although not typically considered a data exfiltration technique, ransomware can involve data exfiltration, especially as an additional tactic to increase the pressure on the victim or to extract more money.

Strategies to Mitigate Data Exfiltration

Many organizations have an outward-looking security strategy; however, preventing data exfiltration requires an inward-looking approach that focuses on data leaving the network. Here are some strategies that can be applied by organizations:

1. The Role of Organizational Culture

Several data exfiltration events occur due to human blunders and indiscretions. And much of this can be mitigated simply by keeping employees well-informed and proactive about security, recognizing their role as a critical line of defense in protecting the organization.

Merely getting people to take security education courses does not cut it anymore, since cyber threats are increasing in volume, scale, and complexity by the day. A better approach to keep employees on their toes is to integrate awareness into the very culture of the organization.

That means being trained to recognize common signs of data exfiltration attempts and reporting all suspicions to the IT team. There should also be clear policies and procedures to protect data. A few best practices that can be implemented include:

• Prohibiting downloads of sensitive data stored on the cloud
• Blocking access to insecure websites over the company network
• Preventing the installation of unauthorized software on devices that can access sensitive data
• Proactive access management by frequently reviewing permissions

2. Adopt the Right Technologies

According to an ethical hacking study, more than 60% of hackers can exfiltrate data in less than five hours once they gain access to a system. This underscores the importance of having strong technical defenses in place.

Some modern technologies that can enhance your defenses against data exfiltration include the following:

• Cloud Access Security Broker (CASB): required intermediaries that offer visibility and control across cloud services via encryption, behavior analytics, data loss prevention, etc.
• Identity and Access Management (IAM): it’s important to set granular access controls to prevent misuse of privileges. Ideally, access should be granted on a role-based, least-privileged, and zero-trust basis to minimize risks.
• Data Detection and Response (DDR): DDR addresses traditional challenges with data security by combining intelligent analytics with real-time data monitoring. Basically, it enables you to follow the data everywhere, particularly when it is in motion and most at risk.

3. Continuous Risk Evaluation

Cloud computing, IoT, and endpoints expansion are some developments in organizational culture that have transformed the dynamics of risk management in recent times. Now, risk evaluation must be a continuous activity to detect threats and vulnerabilities across every network, device, application, and user.

Maintaining a regular log of devices and activities on the network makes it easy to detect and flag unusual events. These can then be evaluated to identify the nature and scope of the threat if indeed they are data exfiltration attempts. Hence, continuous risk evaluation must involve real-time monitoring.

Besides enabling quicker incident response, it also enables the IT team to proactively update security measures to thwart emerging threats, as well as to enforce compliance with organizational security policies. Even the ‘simple’ act of scanning all emails, especially those sent or received by systems/users with access to sensitive data, can prevent several incidents of unauthorized data transmission.

4. Conduct Periodic Audits

Besides continuous risk evaluations, there should also be regular wide-scale audits, at least, twice a year, to sweep through the organization in order to detect possible vulnerabilities. Different from continuous monitoring, periodic audits are systematic reviews of the organization’s security infrastructure, policies, practices, and even humans.

For instance, it is important to audit the set of privileged users who have access to sensitive data and assess their activities to ensure that they are not performing actions that inadvertently put organizational data at risk.

Following each major audit, there should be new directions and instructions for network configurations, access controls, user privileges, data storage practices, and much more. The aim is to identify and eliminate potential sources of weakness and strengthen the organization’s defenses before those weak points are exploited.

Conclusion

It is important to remember that data exfiltration is a constantly evolving threat, and organizations must be prepared to adapt their defenses accordingly. By staying up-to-date on the latest security threats and implementing effective security measures, organizations can protect themselves from data exfiltration and its devastating consequences.