What Is Data Exfiltration and the Ways to Prevent It


Like other common cyber attacks, data exfiltration is a problem facing many organizations. It’s a problem that continues to persist, making life just a little harder for security teams, management, stakeholders, and others associated with your company.

The fact that data exfiltration can be conducted both manually and through automated processes makes it even more of a pain to deal with, especially when you don’t know how to proceed, or what safeguards to put in place to ensure that it doesn’t happen.

In this post we have two goals:

  1. To answer the “what is data exfiltration” question
  2. To outline the various ways to prevent it

Our overarching goal is to help strengthen your cyber security posture through our advice and knowledge on this subject. We’re no stranger to data exfiltration here at TLR, having helped countless organizations combat this form of cyber attack.

Let’s begin by answering the popular “what is data exfiltration” question before turning our attention to how data exfiltration occurs.

What is Data Exfiltration Exactly?

Data exfiltration is the theft or unauthorized removal or movement of any data from a device. This type of cyber attack typically involves a cyber criminal who steals data from personal or corporate devices, such as mobile phones and computers.

In simple terms, data exfiltration is a form of security breach that occurs when either an individual’s or company’s data is copied, transferred, or retrieved from a computer server without the proper authorization.

As mentioned at the top of this post, data exfiltration is an interesting form of cyber attack, as there are multiple ways for this form of cyber theft to occur. It can either happen manually (through devices), or via automated processes (conducted through malicious programming over a network).

Terms such as data exportation and extrusion, data leakage, and data theft are often used interchangeably with the term data exfiltration, which term you choose to use is completely up to you; the definition remains the same.

cyber security on screen

How Does Data Exfiltration Occur Exactly?

Understand that data exfiltration can be difficult to detect, which explains why it’s such a hassle to deal with. It’s difficult to detect as it involves the transfer or moving of data within and outside of a company’s network where it often resembles/mimics typical network traffic.

This allows for substantial data loss incidents; the majority of which you won’t even know about until it’s too late, and exfiltration is already complete.

There are two ways that data exfiltration can occur:

  1. Through outside attacks
  2. Through insider attacks

An attack from outside of your organization occurs when an individual or group infiltrates a network to steal corporate data and things such as user credentials. Hackers typically achieve this by injecting malware onto a device – malware that is connected to a corporate network.

Why someone might choose to exfiltrate your data from the inside is unknown; it varies depending on the person, or group, in question. Most do it for monetary reasons, selling data to the highest bidder – someone that is more than likely planning to exfiltrate your organization with the information gathered.

Sometimes, insider attacks occur simply due to negligence, where an employee, unbeknownst to them, gives hackers the keys to the front door, so to speak, by clicking on a phishing link in an email, for example.

The Various Different Types of Data Exfiltration

Exfiltration almost always occurs over the internet or via a corporate network and the techniques hackers are using are only getting better as time goes on.

This makes it highly important that you understand the various attack techniques of these nefarious individuals, so that you can implement the correct cyber security methods to keep them at bay.

Please see the following list of cyber attack techniques, for reference:

  • Phishing attacks
  • Outbound emails
  • Downloads to unsecure devices
  • Uploads to external devices
  • Human error

Phishing Attacks

Phishing attacks involve emails that are carefully designed by hackers to look legitimate; they even appear to be sent from trusted senders, when in reality, they are one of the most common entryways for hackers when trying to infiltrate your system.

In phishing emails, it’s the attachment or the link included that you need to be careful about. Clicking on either of those things will release the malware within – malware that will steal your data

We covered phishing attacks in a previous post covering advanced endpoint protection. Be sure to check this post out for more information. Doing so will only help to strengthen your understanding of cyber security as a whole!

Outbound Emails

Taking advantage of emails appears to be a calling card of many malicious actors. Hackers are always looking for new ways to use email to exfiltrate any data that sits on an organization’s outbound email system, such as calendars, databases, images, planning documents, and anything else you have lying around.

Downloads to Unsecure Devices

A common form of insider threat, downloads from unsecure devices is another way for hackers to exfiltrate your data.

How they do it is simple:

The malicious actor accesses sensitive corporate information on their trusted device and then transfers the data onto another device. This unsecure device, or unmonitored device, could be something like a camera, an external drive or an unprotected smartphone.

An unprotected smartphone refers to devices that aren’t protected by corporate security solutions or policies.

Uploads to External Devices

Uploads to external devices are almost always the work of a malicious insider. The inside attacker can exfiltrate data by downloading information from a secure device and then uploading it onto an external device.

External device might refer to the following things:

  • Laptops
  • Smartphones
  • Tablets
  • Thumb drives

Human Error

Technology has brought us all closer together, more-so if you work in an organization with multiple departments, each equipped with the latest technology. Unfortunately, this also increases the level of risk in terms of exfiltration.

Human error and procedural issues are one of the largest contributors to data exfiltration, which is why you need to apply the correct systems in place and only give access to the relevant individuals.

Unsecured behavior in the cloud is another thing to watch out for. This is where a bad actor makes changes to virtual machines, they’ll then deploy and install malicious code, and submit malicious requests to cloud services.

magnifying glass on keyboard

How Do You Detect Data Exfiltration?

Detecting data exfiltration can be tough when you consider the various different types of attack methods used. Again, a lot of the time this type of cyber attack will go through your network completely unnoticed, which is bad for many number of reasons.

What you’re going to need to do to prevent data exfiltration is try to identify and detect the presence of bad actors in real time.

You could implement an intrusion detection system (IDS), one that acts as a sort of cyber watchdog, keeping an eye out for any threats.

We call our solution, Cavalry – or CAVs for short – and what CAVs does is it constantly analyzes and detects security or vulnerability issues within your organization’s network. More than just a vulnerability scanner, Cavalry also enhances human operators, allowing them to focus on other tasks while the system does its thing!

Another way to detect data exfiltration is to encourage everyone with access to your system to use common sense and remember what was taught to them in training. This is very helpful when it comes to phishing emails.

Training is another area we can assist you in. Our security bootcamp course helps your people gain a better understanding of security fundamentals, with emphasis on how to react should you come across a malicious actor or anything that’s too out of the ordinary.

How to Prevent Data Exfiltration

Mobile working has only made data exfiltration that much harder to track and confine. Still, that’s not to say that there aren’t ways to prevent this type of cyber attack. Other than the two methods mentioned above, there are many other ways to prevent data exfiltration.

For example, firewalls have the ability to block unauthorized access to resources and systems storing sensitive information. Firewalls are a form of leakage protection, which ensure that any unauthorized transmissions to third-party servers are more than dealt with.

We’d recommend next-gen firewalls (NGFWs) if you’re going to strengthen your cyber security with a firewall. You’ll want a NGFW as they tend to come with a range of modern features, including network monitoring, which is another type of watch dog, similar to CAVs.

Here’s a quick rundown of the various considerations you should consider when deploying data exfiltration-focused security solutions:

  • Maintaining User Experience: Anything you implement must not interfere with the user’s experience, meaning organizations must use prevention tools that can detect issues and not interrupt regular business continuity.
  • Credential Theft/Phishing Prevention: Organizations must look at ways to educate others on what to look out for so that they don’t enter information on spoofed websites. The right tools can also block keystroke logging, which is where a hacker can see keyboard activity.
  • Blocking Unauthorized Channels: There are some strands of malware that use external communication channels to exfiltrate data. Therefore, you need to consider methods that block them.
  • User Education: Similar to what we were saying before about bringing others up to speed, user education is very important as it teaches everyone the telltale signs of what to look out for and how to proceed.
  • What Is Data Exfiltration and the Ways to Prevent It

    Did we accomplish our goals in the end? As in, did we answer your “what is data exfiltration” question, and cover the various ways to prevent it, effectively enough for you to have a decent understanding of what to do next?

    If you still find yourself confused, or if your next steps involve seeking the help of a third party to help strengthen your cyber security, then know that we’re on call to handle either of those things.

    At TLR Global, we help shield your future through expert services that empower you and those around you. We help you become more cyber resilient, eliminating that stigma of fear that is normally tied to the topic of ‘cyber security.’

    We aren’t like other cyber security companies out there, in that we help you future proof your business through agile solutions, but we’d never suggest something that you do well already, or don’t need.

    To find out more, simply get in touch and a friendly member of the TLR team will be in touch shortly.

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Written by

Dave Roberts