Sensitive company data could be slipping out of your network without anyone noticing. And, no, this isn’t a plot from a spy thriller but a real-world scenario called data exfiltration. Information is the new gold, and unauthorised data transfers can have far-reaching consequences, including financial loss and reputation damage. Help safeguard your data by being aware of the risks and taking the right measures to minimise them. Start here and now with premium online privacy and protection for your business: Discover multi-layered Avira Prime.
What is data exfiltration?
It goes by many names, including data extrusion, data exportation, and even just data theft or data leakage (but more on why you shouldn’t call it that below). Whatever the name, data exfiltration refers to the unauthorised transfer of data from an organisation’s network, a computer or other device to an external destination. It’s a type of security breach whereby data is illegally copied, retrieved, or moved, usually by cybercriminals. This data can include anything from customer information and intellectual property to financial records and trade secrets. It’s often notoriously difficult to detect because it cunningly mimics regular network traffic. Operating in “stealth mode”, it can go unnoticed for weeks or even months, and once valuable data is in the wrong hands, it’s difficult to contain the damage.
Data theft is a grave reminder of the importance of protecting sensitive information—and that some of the most serious threats to it can hide in plain sight.
Is it data exfiltration, data leakage, or a data breach?
It’s a good question because these terms are often used interchangeably. They refer to different types of data security incidents, and here’s how to understand the differences (and the overlaps):
Data exfiltration is the deliberate, targeted, and unauthorised data removal from a secure system to an external destination. The intent is malicious, and the attacks are usually sophisticated.
Data leakage happens when sensitive information is accidentally exposed due to human error or a system misconfiguration. There is generally no malicious intent. For example, misconfigured cloud storage grants unauthorised people access to sensitive documents, or emails with confidential attachments are accidentally sent.
Data breach is an umbrella term for a security incident in which protected information is exposed to unauthorised parties. It’s a loss of data control that can result from data exfiltration or leakage.
How does data exfiltration typically happen?
Cybercriminals deploy various methods to lay their hands on sensitive information, but their techniques fall into two broad categories, depending on whether the attack originates from outside or within the organisation:
An outside attack happens when someone infiltrates a network and steals corporate data or user credentials. They’ll usually inject malware onto a computer connected to the corporate network, and every device is a potential entry point, whether it’s a laptop, smartphone, or even a USB stick. Poorly secured cloud storage can become a treasure trove for data thieves, who eagerly exploit security vulnerabilities in outdated software.
An inside breach occurs when a malicious insider steals their own organisation’s data, usually to sell it to cybercriminals and other unauthorised third parties. It can also be caused by plain carelessness, like staff using unsecured public Wi-Fi, weak passwords, or falling for phishing attacks (in which scammers trick employees into revealing credentials or downloading malware).
What you don’t know really can hurt you.
What attack techniques does data exfiltration rely on?
Data exfiltration usually occurs via the internet or a corporate network, and methods vary. Whether it’s the result of an angry insider or a technical security vulnerability, attacks are becoming increasingly sophisticated, making them harder to detect. Let’s explore the common methods currently being deployed:
Social engineering
Social engineering attacks tend to be the most common and showcase attackers’ creativity and patience. All it takes is a poorly trained or distracted employee to accidentally act as a (wo)man on the inside. During phishing attacks, for example, victims receive an email that looks legitimate and contains a link to a fake website or an attachment laced with malware like ransomware. If they click on a link and enter their login credentials, this information is stolen. There are also smishing (via text) or vishing (voice message) attacks, which impersonate a trusted sender and ask the recipient to hand over specific information or make payments. Sometimes, attackers launch whaling attacks that target a single (high-profile or “heavyweight”) user, like the company CEO, a celebrity, or a high-net-worth individual. There are also highly targeted spearfishing campaigns that are called BEC or business email compromise. Here, a cybercriminal sends employees emails that seem to be from another employee, associate, vendor or customer—and they’re tricked into paying fake invoices or divulging sensitive information.
Outbound emails
Outbound email systems are data treasure chests packed with calendars, databases, images, and planning documents. Cybercriminals lie in wait to steal information as it travels along in emails and file attachments.
Covert channels
These communication channels are used to send information from one network user to another. They can carry severe risks as they allow data to be secretly extracted from within a system without triggering alerts or being detected by an antivirus.
Poorly secured cloud technology
Cloud services are convenient because they’re always on and can be accessed remotely, but it’s precisely these qualities that make them attractive targets for data thieves. Hackers can access cloud data by hijacking an administrator’s account or fooling employees into handing over login credentials or sensitive information. Careless staff might also accidentally share access codes or download malicious software that lets a bad actor make changes to a virtual machine. Then there’s the cloud service itself—less reputable services don’t have adequate security measures.
Downloads to external devices
A malicious or careless insider is usually to blame here, as they download data from a secure corporate device like a laptop to an insecure, external device like a USB drive, smartphone or another laptop. Android devices are often considered more vulnerable to malware that can take control of the phone to download applications without the user’s consent.
How can you detect data exfiltration?
Unmasking data exfiltration is challenging but (thankfully) not impossible. The key is taking a multi-layered approach that’s designed to identify suspicious patterns and out-of-the-ordinary user behaviour. IT teams need to carefully track:
- Unusual network traffic: Monitor for unexpected spikes in outgoing data, especially to unfamiliar IP addresses. Automated tools can scrutinise outgoing emails for large attachments, suspicious content, and unauthorised recipients.
- User access logs: Keep an eye on irregular login patterns, especially from unusual locations. Is an employee accessing large amounts of sensitive data they wouldn’t typically need? Have new accounts been created without authorisation, or has there been a surge in failed login attempts?
- File activity patterns: Track large file downloads or repeated access to sensitive documents or unusual file types.
- Suspicious DNS queries: Attackers use DNS tunnelling to turn the Domain Name System into a hacking tool to exfiltrate data. Always investigate DNS queries that lead to known malicious domains.
In a nutshell, you need to be relentlessly on the ball to help stop data exfiltration in its tracks—when it comes to monitoring users, data transfers, and systems, your work is never done.
What are the possible consequences of data theft?
The ramifications of data exfiltration can be far-reaching. Remembering the serious consequences can help users be more mindful of their actions. There can be financial impacts, as data breaches are usually expensive to recover from. Consider the costs of investigations, legal fees and possible fines. And what about the costs to a reputation? Customers may lose faith in a company that fails to protect their information, and this can lead to a loss of business. There are also legal issues to consider. Failing to protect sensitive data can violate privacy regulations, and organisations may face lawsuits and fines.
Are you proud of a new product development initiative or manufacturing process, for example? Data exfiltration could compromise trade secrets and weaken your company’s competitive advantage—and it can even grind business to a halt if data loss impacts operations. And where will it end? Data exfiltration can also be used as a springboard for other malicious activities, such as fraud or extortion.
Famous examples of data exfiltration
To truly understand the methods and dangers of data exfiltration, let’s see it in action with these real-life examples.
In 2014, eBay suffered a breach that impacted around 145 million users. Cybercriminals used stolen employee log-in credentials to gain unauthorised access to eBay’s corporate network.
In 2020, British Airways was fined £20 million after a massive data breach. Attackers exfiltrated the data of over 400,000 customers, including credit card numbers, names, and addresses.
In 2022, chipmaker Nvidia experienced a cyberattack by ransomware group LAPSUS$, which threatened to leak 1 TB in exfiltrated data.
How should you respond to data exfiltration?
If you suspect data exfiltration, swift action is critical to help minimise the damage and help prevent further problems. Here is a suggested incident response plan:
Step 1: Understand the scope of the attack: What information has been accessed? How long has the attacker been in the system? Larger organisations will have a team trained to handle data breaches and security incidents, and they will help pinpoint what was stolen, when, and (hopefully) by whom.
Step 2: Contain the breach: Immediately isolate the affected systems to help contain the damage. This might involve taking compromised servers offline, disabling network connections, or revoking access for certain accounts. Don’t go nuclear. Tread carefully to maintain business continuity.
Step 3: Investigate the incident and preserve evidence: Use forensic tools to determine how the breach occurred and what data was compromised. Thoroughly review logs and data access points to understand what the attacker exploited and how they evaded detection. And document everything—this will be critical when reporting the incident and making security improvements later.
Step 4: Notify authorities and affected parties: Companies are usually legally obligated to disclose a data breach, so you may need to report the incident to the relevant regulatory bodies and law enforcement. It’s also vital to be transparent with stakeholders (including employees, customers, vendors, and partners) to help reassure them and restore trust. Let them know what’s been compromised, how this could affect them, and the steps you’re taking to help protect them.
Step 5: Remediate and review: Learn from the incident and use it as an opportunity to review and strengthen security policies. Do you have enough visibility into systems? Were there warning signs you missed? Could automation have prevented the breach and sped up your response time? Take action: Patch vulnerabilities, update security protocols, and retrain staff to help prevent future incidents.
How can you help prevent data exfiltration?
When it comes to data theft, an ounce of prevention is worth a pound of cure. A comprehensive security strategy should blend advanced user and data monitoring tools with intelligent threat detection to help find unauthorised activity as soon as it occurs. It’s not all about technology, though: IT teams and all staff must develop a “zero trust, always verify” approach company-wide!
- Implement strong access controls: Use multi-factor authentication (MFA) and limit access to sensitive data on a need-to-know basis. Be on high alert for failed login attempts or users suddenly accessing files they don’t usually need. Make sure that access controls are routinely re-evaluated and revised. Has someone changed departments or left the company, for example?
- Monitor networks with advanced automated security stools: Use intrusion detection systems (IDS) and data loss prevention (DLP) tools. Combine these with network detection and response (NDR) solutions to monitor network traffic patterns and help detect potential data theft in real time. And don’t forget the essentials: A firewall helps protect against data theft by filtering network traffic and blocking malicious or unnecessary traffic.
- Deploy end-to-end encryption: Cryptography helps protect against data theft by scrambling data into an unreadable format. Only people with the correct decryption key can access the data. Also, make sure that staff use a VPN when working remotely and always use a VPN on public Wi-Fi.
- Conduct regular risk assessments: Help identify weaknesses by regularly reviewing security protocols and user access.
- Update software: Keep all systems and applications rigorously up to date to patch security vulnerabilities that hackers might exploit. And don’t forget to update your drivers
- Train employees: Teach staff to recognise phishing attempts and follow best practices for data handling.
Take a robust, multilayered approach to your online security
Avira Prime blends premium privacy, protection, and performance tools into a single subscription. Its Antivirus Pro can detect malware in real-time, and if you’re redirected to an infected website, the Secure Browsing tool helps block it. The integrated Password Manager Pro generates, remembers and helps store complex, unique passwords for all your online accounts. Remote workers will appreciate the VPN to help secure and anonymise their web browsing. Avira Prime is also conveniently cross-platform: Choose what you and your staff need with premium Avira protection for PC, Mac, Android and iOS.
Data exfiltration poses a significant threat to organisations of all sizes, but we can help protect ourselves: Understanding the risks and implementing proactive measures greatly reduces our vulnerability. Invest in robust security solutions to help keep data and systems safer and always stay vigilant. You won’t just be safeguarding your data integrity—you’ll help maintain the trust of your customers and partners.