Data Exfiltration: What You Need To Know To Protect Yourself

Data Exfiltration:

Data Exfiltration: What You Need To Know To Protect Yourself

Exfiltration in cybersecurity is a major threat to businesses in this digital age. This article highlights techniques used by cybercriminals and how to protect yourself.

What is exfiltration in cybersecurity?

Data exfiltration is the unauthorized transfer of data from a computer or network. It refers to the theft or extraction of confidential or sensitive information, such as intellectual property, trade secrets, or personal data, by an individual or group.

There are various ways to carry out exfiltration in cybersecurity, including both manual methods, such as physically accessing a computer and copying sensitive information, and automated methods, such as using malicious software to extract data over a network.

Insider threats can be a major cause of data exfiltration, unintentional or intentional. A malicious insider threat is a person trusted within an organization and deliberately extracts sensitive data to harm the organization or benefit themselves or someone else.

Data exfiltration can be challenging to detect, as it resembles normal network traffic and may not be noticed until after the data has been transferred out of an organization’s network successfully. It can make it difficult to prevent significant data loss, as the exfiltration may go unnoticed until it is too late.

The consequences of data exfiltration can be severe. Valuable information can fall into the hands of hackers, resulting in significant financial and reputational damage.

How does data exfiltration happen?

As mentioned, there are several ways exfiltration in cybersecurity can happen. The most common are internal and external exfiltration. 

Again, internal exfiltration refers to a situation where someone with legitimate access to a database extracts or downloads sensitive data for personal gain. This type of data exfiltration can occur when an individual has access to the data as part of their job duties but decides to misuse that access for their benefit.

Internal data exfiltration does not always involve intentional wrongdoing. In some cases, it may result from an employee’s negligence or lack of awareness about proper security protocols. 

For example, an employee who forgets to enable server authentication or leaves a server unprotected for an extended period may inadvertently expose the data on that server to potential hackers.

External data exfiltration refers to an outsider’s unauthorized access or use of data. It can include hackers who gain access to a system or network by exploiting vulnerabilities, using malware, or using social engineering tactics to obtain login credentials.

Both internal and external data exfiltration can pose a significant risk to your organization, as a large amount of data may be vulnerable to theft or misuse.

Common methods used by attackers to exfiltrate data

Outsider threats

It is the main threat from malicious outsiders. They may attempt to access a company’s sensitive data to compromise it. These actors may use various techniques with social engineering as the primary tactic. Some techniques include.

  • Scareware: It is malware designed to manipulate users into believing that they need to download or purchase malicious software to fix a computer problem. The malware is often delivered through pop-up ads or fake security alerts that warn the user of a supposed issue with their system.
  • Waterhole: It is a targeted cyber-attack designed to compromise a specific group of users by infecting websites they visit regularly. The attackers will set up a malicious website to lure the targeted users to the site, where the malware will infect their systems. A watering hole attack aims to infect the user’s computer with malware and gain access to the organization’s network.
  • Whaling: It is a highly targeted phishing attack designed to target senior executives. These attacks deceive the victim into believing they are receiving a legitimate email. The attackers may then attempt to encourage the victim to perform a secondary action, such as initiating a wire transfer of funds.

Other common outsider techniques include dumpster diving, shoulder surfing, tailgating, pretexting, and diversion theft.

Phishing attacks

Phishing emails are one of the primary methods malicious outsiders use to distribute malware and exfiltrate data. These emails trick the recipient into believing they are receiving a legitimate message from a trusted source. 

They often contain links or attachments that, when clicked or opened, will install malware on the victim’s computer. According to a report from Bolster, In 2021, they detected approximately 10.7 million phishing and scam pages. 

Transferring data to vulnerable devices

They occur when a person retrieves and views data through a legitimate and approved channel but then copies and saves the information onto a device that lacks adequate security measures. 

It might happen, for example, if a user logs into a secure network using a password and then copies sensitive documents onto a personal laptop that does not have up-to-date antivirus software installed.

 In such cases, the data is at risk of being accessed or stolen by unauthorized parties if the device is not adequately protected.

Exporting data to external systems

The process involves copying and saving sensitive data onto local devices or servers and then transferring it to another organization or individual using a web browser or other software that is not monitored or controlled by the source. 

This method of uploading data to external services may be risky, as the data may be vulnerable to being accessed or stolen by unauthorized parties during the transfer process or after it has been uploaded to the third-party service. Besides, one might upload the wrong information. 

Cloud apps

Individuals with technical capabilities, such as installing software, modifying virtual machines, or accessing cloud storage, can steal and transfer data from a secure environment. 

Additionally, individuals with the necessary permissions may move data from secure containers to less secure ones. They can also create new services without proper authorization, potentially exposing the company to security risks.

Best practices for preventing data exfiltration

Monitor for programs that are leaking large amounts of data

Exfiltration in cybersecurity is slow. As you’d expect, if a large amount of data is transferred out of a network, it would be unusual and likely to stand out as suspicious. This sudden, high-bandwidth data transmission would likely be noticed and could be quickly shut down to prevent any potential data exfiltration.

However, data exfiltration is different. It involves transferring data at very low speeds, with only small amounts of data being sent per second. It can make the attack difficult to detect, as the data transfer may be hidden among the many other legitimate communications and services transmitting data from a network.

Be cautious of programs that are not entirely legitimate

Both attackers and legitimate users can utilize the same types of programs to achieve their goals. For example, technical support staff can use remote desktop support programs to troubleshoot issues with a user’s computer remotely. However, attackers can abuse the same programs to steal data from a target system. Other software to monitor include Metasploit and Curl, among others.

Look at the file formats being uploaded

If you suspect that a program used for legitimate purposes has been modified or repurposed to steal data. It can be helpful to examine the data being transferred. One potential indicator of data exfiltration is uploading compressed or encrypted data through the program. 

It may suggest that someone secretly transfers sensitive information out of a network.

Block or redirect suspect data uploaders

If data exfiltration is successful, you’ll want to know how the program got there. It is where you use the sinkhole technique. It is a technique used in network engineering to redirect traffic from a malicious program to a specified IP address. It can block or disable the program’s ability to communicate with other systems or effectively transmit data.

As such, you will see how the malicious program is exfiltrating data while preventing it from more exfiltration. It will allow you to study the program and understand how it got there.


Implementing strong security measures, such as using firewalls, encrypting your data, and educating yourself and your employees on best practices to protect yourself from data exfiltration. So, take these steps and protect your company from exfiltration in cybersecurity and its potential consequences. If you would like to have this responsibility taken off of your hands Total Tech is here to help. Contact us today to learn more!

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