What is data exfiltration?

Unauthorized data transfer, or data exfiltration, is a significant threat to organizations. Learn how data exfiltration happens and essential strategies to prevent it.

Learning Objectives

After reading this article you will be able to:

  • Understand what data exfiltration is
  • Learn common data exfiltration techniques
  • Discover detection and prevention methods

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What is data exfiltration?

Data exfiltration is the deliberate and unauthorized transfer of data from computers or networks to an external computer or network controlled by an attacker. Cybercriminals employ diverse tactics to exfiltrate data, from sophisticated malware, to deceptive phishing attacks to outright physical theft. They aim to steal sensitive information such as intellectual property, financial details, or personal data, which can result in financial losses, tarnished reputations, legal consequences, and compromised security.

An example of data exfiltration is if an attacker gains access to a private corporate network and copies private messages, financial data, and other sensitive details. They could use this information for malicious purposes such as financial fraud or selling your information to third parties.

What is the difference between data leaks and data exfiltration?

Data leaks and data exfiltration are similar in that they both involve the exposure of previously secure data. However, a data leak occurs accidentally, such as when a company accidentally exposes internal data to the Internet due to a security misconfiguration. Data exfiltration, however, involves a deliberate attempt to steal sensitive information, like when a malicious insider takes valuable company data.

What are common data exfiltration techniques?

Common data exfiltration techniques include:

  • Phishing attacks are when attackers impersonate trusted entities to trick victims into revealing sensitive information like usernames, passwords, or bank account data.
  • Malware is software designed to disrupt normal operations of a device. Keyloggers are one example: they silently collect data and send it to an external source.
  • Insider threats involve malicious insiders within an organization using existing privilege to access and extract information. For example, an employee might intentionally upload data to a public cloud, hard drive, or a large language model (LLM) .
  • Social engineering attacks manipulate victims into sharing sensitive information.

How can organizations detect and prevent data exfiltration?

To protect against data exfiltration, it is important to adopt best practices and deploy effective security tools. One key strategy is implementing a Zero Trust approach. Zero Trust is a security model that requires strict identity verification for every person and device accessing a private network. Its main principles include continuous monitoring and validation, least privilege access, device access control, microsegmentation, prevention of lateral movement, and multi-factor authentication (MFA).

Monitoring network traffic and connected devices allow crucial visibility to authenticate and verify users and machines. Applying the principle of the least privilege – from executives to IT teams – helps minimize the damage if a user account is compromised.

Another effective strategy to prevent data exfiltration is data loss prevention (DLP). DLP is a set of tools and processes used to detect and block data in outgoing traffic. DLP security solutions track data within the network, analyze network traffic, and monitor endpoint devices to identify potential loss of confidential information.

How does Cloudflare help reduce data exfiltration risks?

The Cloudflare One platform offers unified security capabilities, including DLP, to protect data in transit, in use, and at rest across web, SaaS, and private applications. Cloudflare One inspects files and HTTPS traffic for sensitive data and allows customers to configure policies to allow or block such data. Cloudflare One also integrates remote browser isolation (RBI) to enhance DLP features by restricting downloads and uploads, keyboard input, and printing. Learn more about Cloudflare One.