Data exfiltration: understanding, detecting, and preventing 

Data exfiltration is a substantial threat in the digital landscape that has been gaining traction slowly but surely in the last couple of years. In this blog post, we’ll investigate the meaning of data exfiltration, explore various techniques employed, discuss its detection, examine its potential impact, and provide insights into preventing data theft from your Microsoft 365 environment.

What is data exfiltration?

In its simplest terms, data exfiltration is the unauthorized removal of data from a computer, marking the culmination of many cyber attacks – even more simply, data exfiltration is data theft. Whether intentional or accidental, the aftermath of successful data exfiltration can be severe, leaving organizations grappling with the repercussions.

Data exfiltration techniques

Data exfiltration techniques are diverse but generally fall into two broad categories: 

1. Outsider data exfiltration

This type of data theft is done by individuals outside an organization that use automated tools and complex methods (such as social engineering and phishing attacks) for sophisticated data exfiltration.

2. Insider data exfiltration:

Insider exfiltration can be malicious, but it is often accidental – an employee or an external collaborator might inadvertently share files and data with people outside your organization. A common example of malicious insider data exfiltration is when employees with access to sensitive data leave the organization but decide to take a lot of data with them first.

Data theft: A quick Look

Whether intentional or accidental, insider threats can lead to prolonged data theft incidents. An infamous example of malicious insider data exfiltration is Dongfan “Greg” Chung, who extracted data from Boeing over a span of 30 years and managed to steal over 250,000 pages of highly sensitive and confidential documents, including data about the Space Shuttle.

Remember that Dongfan “Greg” Chung used only “old-school” data exfiltration methods. Who knows how much information could be exfiltrated by abusing modern technological capabilities?

In contrast, a cybercriminal used stolen privileged credentials procured on the dark web to gain access to Medibank’s internal systems in November 2022. They exfiltrated 200 GB of customer data that included names, birth dates, passport numbers, and information on medicare claims. This was Australia’s largest data breach, which resulted in the company having to set aside 167 million US dollars to deal with the aftermath.

However, as mentioned, not all data exfiltration is malicious. A couple of years ago, an employee accidentally downloaded the data of 44,000 Federal Deposit Insurance Corporation customers onto one of their personal storage devices and took it with them, just like that.

If you’re looking for more detailed information about how to deal with insider threats in Microsoft 365, look at our blog post Insider threats in cyber security: What happens when employees leave or learn how to manage user offboarding in Microsoft 365.

Data exfiltration detection

Detecting data exfiltration is crucial to mitigating and preventing its impact. It involves monitoring network activities and identifying unusual patterns or unauthorized access. 

Without full visibility into your Microsoft 365 environment, finding out who did what and where can be incredibly hard and time-consuming. 

For example, the average time to detect and contain a data breach, as per an IBM 2023 study, is a staggering 277 days, emphasizing the need for swift and proactive detection mechanisms.

The cost of data exfiltration

Data exfiltration can disrupt operations, damage customer trust and reputation, and lead to financial losses. The average cost of a data breach in 2023 was 4.45 million US dollars. Notably, all data exfiltrations are data breaches, but not all data breaches involve data exfiltration.

Preventing data exfiltration in Microsoft 365

If you’re looking to secure your data and prevent data exfiltration in Microsoft 365, implementing a combination of technical measures, user training, and proactive security practices is essential. Here are the steps you can take:

• Access controls: Configure permissions carefully, regularly review and update access controls, and use conditional access policies.
• Data encryption: Enable encryption for data at rest and in transit within SharePoint.
• Monitoring and auditing: Implement logging and auditing features in SharePoint to track user activities.
• Endpoint security: Ensure devices accessing SharePoint are protected with up-to-date antivirus software.
• Data Loss Prevention (DLP): Implement DLP policies to detect and prevent the unauthorized sharing of sensitive information.
• User training and awareness: Provide comprehensive training on data security best practices.
• Multi-Factor Authentication (MFA): Enable MFA for an additional layer of security.
• Incident response plan: Develop and regularly update an incident response plan.
• Regular security audits: Conduct regular security audits and vulnerability assessments.

How to prevent data exfiltration in Microsoft 365 with Syskit Point

Securing your valuable data within Microsoft 365 is paramount, especially considering the risk of data theft.

To do that, you must adopt a robust security mindset. Syskit Point offers comprehensive solutions to enhance your security posture and prevent data exfiltration effectively.

Syskit Point’s multipronged security approach

To create a safe environment, it’s all about multiple layers of security. Like an ancient medieval fort, you need multiple defensive obstacles to cover all your blind spots.

1. Regular access reviews

Syskit Point lets you configure regular access reviews, enabling you to audit sensitive content seamlessly. This automation not only reduces the burden on your IT team but also ensures that the process is handled by employees with the best operational knowledge. Complete control over user access, coupled with full transparency into who has access to specific resources, is vital for preventing unauthorized data access.

2. Tracking admin and user activity

With Syskit Point, you gain in-depth insights into admin and user activities across your entire Microsoft 365 tenant. This visibility is crucial for identifying any suspicious behavior that might indicate potential data exfiltration attempts.

3. Control over external file sharing

Syskit Point empowers you to take control of external file sharing within Microsoft 365. By checking the details of sharing links and obtaining a centralized report of all shared content, you can effectively manage and monitor external collaboration. Removing or stopping sharing with just one click ensures that access is revoked when it is no longer needed or appropriate.

4. Lifecycle management

Syskit Point addresses the daily and common Microsoft 365 lifecycle management challenges. One such challenge is hidden guest access, a powerful feature allowing collaboration with external users. Syskit Point allows you to monitor this access efficiently, providing a comprehensive external sharing report. This report lists external users within the tenant and details their access, offering visibility into content vulnerable to data exfiltration.

5. Custom alerting system

Syskit Point lets you configure the alerting system you need. With it in your toolbelt, you can get the information you need when you need it by configuring alerts to see:

• Someone has shared a document with an external user.
• An external user has been added to a team.
• Someone has changed a group’s privacy from private to public.
• A user has logged in from outside the allowed IP range.
• Someone made site administration changes.
• Other permission changes and suspicious user activities have happened.

Stay safe

In the dynamic landscape of Microsoft 365, preventing data exfiltration requires a proactive and comprehensive approach. Syskit Point emerges as a powerful ally, providing the tools and insights necessary to secure your valuable data effectively.

By automating access reviews, tracking user and admin activities, controlling external file sharing, and addressing Microsoft 365 lifecycle management challenges, Syskit Point empowers organizations to stay ahead of potential security threats and safeguard their data integrity.