What Is Data Exfiltration?

A common data exfiltration definition is the theft or unauthorized removal or movement of any data from a device. Data exfiltration typically involves a cyber criminal stealing data from personal or corporate devices, such as computers and mobile phones, through various cyberattack methods.

Another data exfiltration meaning is data exportation and extrusion, data leakage, or data theft, which can pose serious problems for organizations. Failing to control information security can lead to data loss that could cause reputational and financial damage to an organization.

How Does Data Exfiltration Occur?

Data exfiltration occurs in two ways, through outsider attacks and via insider threats. Both are major risks, and organizations must ensure their data is protected by detecting and preventing data exfiltration at all times.

An attack from outside the organization occurs when an individual infiltrates a network to steal corporate data and potentially user credentials. This typically is a result of a cyber criminal injecting malware onto a device, such as a computer or smartphone, that is connected to a corporate network. 

Some strands of malware are designed to spread across an organization’s network and infiltrate other devices, searching for sensitive corporate data in an attempt to exfiltrate information. Other types of malware will lay dormant on a network to avoid detection by organizations’ security systems until data is exfiltrated subversively or information is gradually collected over a period of time.

Attacks can result from malicious insiders stealing their own organization’s data and sending documents to their personal email address or cloud storage services, potentially to sell to cyber criminals. They can also be caused by careless employee behavior that sees corporate data fall into the hands of bad actors.

Types of Data Exfiltration—Attack Techniques

Data exfiltration occurs in various ways and through multiple attack methods. Exfiltration most typically occurs over the internet or on a corporate network. 

The techniques cyber criminals use to exfiltrate data from organizations’ networks and systems are becoming increasingly sophisticated, which help them avoid detection. These include anonymizing connections to servers, Domain Name System (DNS), Hypertext Transfer Protocol (HTTP), and Hypertext Transfer Protocol Secure (HTTPS) tunneling, direct Internet Protocol (IP) addresses, fileless attacks, and remote code execution. 

Common data exfiltration types and cyberattack techniques include the following.

1. Social Engineering and Phishing Attacks

Social engineering and phishing attacks are a popular network attack vector used to trick victims into downloading malware and giving up their account credentials. 

Phishing attacks consist of emails designed to look legitimate and often appear to be from trusted senders. They will either contain a malicious attachment that injects the user’s device with malware or a link to a website that looks similar to a legitimate website but is spoofed to steal the login credentials the user enters. Some attackers also launch targeted phishing attacks that aim to steal data from a specific user, such as senior company executives or high-worth individuals like celebrities or politicians.

2. Outbound Emails

Cyber criminals use email to exfiltrate any data that sits on organizations’ outbound email systems, such as calendars, databases, images, and planning documents. This data can be stolen from email systems as email and text messages or through file attachments. 

3. Downloads to Insecure Devices

This data exfiltration method is a common form of accidental insider threat. The malicious actor accesses sensitive corporate information on their trusted device, then transfers the data onto an insecure device. This insecure or unmonitored device could be a camera, external drive, or smartphone that is not protected by corporate security solutions or policies, which puts it at high risk of the data being exfiltrated.

Smartphones are also susceptible to data exfiltration, with Android devices vulnerable to being installed with malware that takes control of the phone in order to download applications without the user’s consent.

4. Uploads to External Devices

This type of data exfiltration typically comes from malicious insiders. The inside attacker can exfiltrate data by downloading information from a secure device, then uploading it onto an external device. This external device could be a laptop, smartphone, tablet, or thumb drive.

5. Human Error and Non-secured Behavior in the Cloud

The cloud provides users and businesses with a multitude of benefits, but along with it are significant data exfiltration risks. For example, when an authorized user accesses cloud services in an insecure manner, they enable a bad actor to make changes to virtual machines, deploy and install malicious code, and submit malicious requests to cloud services. Human error and procedural issues also play a role in data exfiltration, as the appropriate protection may no longer be in place.

How Can You Detect Data Exfiltration

Depending on the type of attack method used, detecting data exfiltration can be a difficult task. Cyberattacks using techniques that are more difficult to detect can be mistaken for regular network traffic. This means they can lurk in networks unnoticed for months and even years, while the data exfiltration will often only be discovered when the damage has been caused to the organization.

To detect the presence of bad actors, organizations must look into tools that discover malicious or unusual traffic automatically and in real time. 

One tool that offers this capability is an intrusion detection system (IDS), which monitors a network and searches for known threats and suspicious or malicious traffic. When it detects a possible threat, the IDS sends an alert to the organization’s IT and security teams. IDS applications can be either software, which runs on hardware or network security solutions, or cloud-based, which protects data and resources in cloud environments.

These tools work by searching for known attack signatures and detecting anomalies that deviate from regular network activity. They then issue an alert or report of the anomaly so that system administrators and security teams can examine them at the application and protocol layer.

Once risks have been detected, organizations can analyze the risk using tools like static malware analysis and dynamic malware analysis. These enable organizations to understand the threat and the potential impact it could have on devices and networks.

In addition to detecting standalone threats, organizations can also build out the entire sequences of an event as it happened, including mapping them to a known kill chain or attack framework. They can then create a custom detection system that meets their unique risk profile without the need for threat hunters and expensive data scientists.

Data Exfiltration Prevention

Aside from detecting potential risks and protecting data, systems, and users from security attacks without impacting performance and user productivity, organizations should be able to prevent data exfiltration. This has become increasingly difficult given the mobile and remote working trends of the modern workforce. 

Organizations therefore must prevent sensitive data from being transmitted to unidentified servers in locations with high levels of cyberattacks. They should also prevent the unauthorized transmission of data to third-party servers, which are increasingly becoming the source of modern cyberattacks.

Preventing data exfiltration is possible with security solutions that ensure data loss and leakage prevention. For example, firewalls can block unauthorized access to resources and systems storing sensitive information. On the other hand, a security information and event management system (SIEM) can secure data in motion, in use, and at rest, secure endpoints, and identify suspicious data transfers.

Next-generation firewalls (NGFWs) enable organizations to protect their networks from internal and external cyber threats. They maintain features like IP mapping, IPsec and secure sockets layer (SSL) virtual private network (VPN) support, and network monitoring. NGFWs also enable deeper traffic inspection that allows organizations to identify and block attacks and malware across their entire attack surface. NGFWs automatically update to prevent data exfiltration from new and advanced attacks and protect networks from emerging threats. 

Preventing data from being exfiltrated is reliant on deploying a security solution that includes features such as: 

  1. Blocking unauthorized communication channels: Some strands of malware use external communication channels to exfiltrate data. Organizations therefore must block any unauthorized communication channels, such as direct and potentially compromised applications.
  2. Credential theft and phishing prevention: The prevalence of phishing attacks means companies must be able to prevent users from entering their login credentials into spoofed websites. Prevention tools can also block keystroke logging, which enables an attacker to monitor and log a user’s keyboard activity.
  3. Maintaining user experience: Preventing data exfiltration must not negatively impact user activity. Therefore, organizations should use tools that can detect legitimate application and communication activity, even on new applications.
  4. User education: Educating users on the risks and threats they face is also important in detecting data exfiltration. Organizations need to ensure that employees understand the telltale signs of a cyberattack, not open malicious attachments, and not click on links included in emails.

Are Antivirus and Malware Solutions Enough to Prevent Exfiltration?

Antivirus and anti-malware solutions do not provide enough cover to prevent data exfiltration. Antivirus solutions only remove known threats or malware, rather than prevent an attacker from infiltrating the organization’s network. In addition to an antivirus or anti-malware solution, organizations need to deploy solutions that prevent all devices connected to the network from exfiltrating data.

How Fortinet Can Help

Fortinet enables businesses to prevent data exfiltration with its FortiGate next-generation firewalls (NGFWs). NGFWs offer security-driven networking that reduces the complexity and cost of network security. They include industry-leading features like an intrusion prevention system (IPS), SSL inspection, and web filtering, which enable full visibility and protection of any edge.

As a result, Fortinet NGFWs are uniquely positioned to meet the performance requirements of organizations’ hybrid and hyperscale IT architectures. They guarantee optimal user experience levels and manage businesses’ security risks to achieve enhanced business continuity. They enable organizations to inspect incoming and outgoing traffic at unparalleled levels of performance, scale, and speed, without having a negative impact on user experience and costly downtime.

Fortinet NGFWs are an integral part of the Fortinet Security Fabric, which enables them to communicate with third-party security solutions. It also integrates seamlessly with the Fortinet artificial intelligence (AI)-powered solutions FortiGuard and FortiSandbox. This ensures businesses can prevent data exfiltration through known threats, emerging risks, and zero-day attacks. They also enhance operational efficiency by integrating with the Fortinet Fabric Management Center.