Data breaches happen when criminals bypass network security measures and steal data that should remain private. When that happens, they can sell the data on the Dark Web or use it in identity theft attacks or targeted phishing campaigns.

Unfortunately, mitigating data breaches is far from simple. Attackers have many weapons, from phishing and ransomware to exploits, SQL injection, and insider threats. Every attack technique demands a response, as one loose end can leave an entire network exposed.

This article will introduce the critical types of data breaches and mitigation measures to secure your data.

Key takeaways

• Data breaches are extremely costly. The average data breach costs $4.88 million, while reputational harm can be permanent. Mitigation measures are critically important.
• Phishing is the most common data breach type. Phishers rely on human error and lack of knowledge to encourage unsafe behavior. Dark web scanning and employee training are effective responses.
• Ransomware locks data and devices, enabling data theft by attackers. Companies need robust malware protection to avoid infection. File scanning is an essential mitigation measure.
• Insider threats and physical theft can also expose data. Encrypt sensitive data to counter thieves and monitor user activity to detect malicious insiders.
• Other data breach causes include SQL injection, man-in-the-middle attacks, supply chain attacks, cloud misconfiguration, and weak passwords. Each attack requires attention and mitigation actions.
• Specialist data security tools can help you avoid costly breaches. Implement dark web scans to detect compromised data and use business VPNs to block infiltrators.

Phishing attacks: The most common type of data breach

Phishers use persuasion and deception to obtain confidential information from their victims, and they often succeed. According to Verizon’s 2024 Data Breach Report, 68% of data breaches start with human error.

All organizations are vulnerable to social engineering attacks. If your employees use email and share information online, phishing is a critical data breach risk.

The most common form of phishing involves using fake emails that resemble messages from trusted sources. Recipients download malware-infected attachments, which harvest data from their devices. Alternatively, they might click links to fake websites where phony data entry forms request sensitive data.

However, email phishing is not the only variety. Phishers might use SMS messages, phone calls, or video messages (vishing) to achieve their aims.

Whatever method attackers use, the outcome is similar. Victims unwittingly provide personal details, financial information, or login credentials. Criminals use that data to launch identity theft attacks or steal data after accessing private network assets.

Detecting phished credentials before attackers use them

Phishers are challenging adversaries, but companies can strengthen their defenses with dark web scanning.

Criminals use underground marketplaces on the Dark Web to sell stolen credentials and personal information. Criminal groups then use that data in targeted attacks, including large-scale data theft.

Dark web scanners monitor underground marketplaces and provide early warnings about data theft. Victims learn rapidly if their credentials are available for sale. This creates a critical window to reset passwords and secure user accounts before data breaches arise.

We recommend working with expert partners to track your data on the Dark Web. A Dark Web scan for leaked emails and credentials can identify risks and give you time to block phishing attacks.

In addition to dark web scanning, organizations must arrange employee training so employees can understand phishing risks. Most phishing attacks succeed due to human error. Regular training exercises refresh employee knowledge and help users identify risky attachments or links.

Ransomware cyber-attacks

Ransomware is malicious software that locks devices and encrypts data until victims pay a ransom.

Early ransomware attacks focused on financial gain, but this is changing. Attackers routinely steal data if the ransom is not paid. However, data loss is still possible when victims pay in full. The bottom line is that ransomware attacks always put customer data at risk.

For example, the US health company Change Healthcare suffered a ransomware attack in early 2024 by the ALPHV/Blackcat group. Attackers did not just extract a $22 million ransom payment; they stole 4TB of patient data in a so-called “exit scam.”

In total, around 190 million individuals were affected by a single malware infection. Companies need robust defensive measures to secure data and prevent similar incidents.

Reducing ransomware risk with automated malware detection

Best practices to prevent malware attacks include using up-to-date intrusion detection systems and malware scanners. Companies should encrypt confidential information and train staff to avoid phishing emails.

However, it pays to adopt a defense-in-depth with download protection. Companies rely on file transfers from internal and external sources. Any file could carry ransomware agents, making accurate file scanning essential across all devices and endpoints.

Scanning tools ensure malware protection by allowing harmless traffic and identifying high-risk files. A focused approach avoids false alarms, allowing security teams to concentrate on critical ransomware risks.

Insider threats

Insider threats come from individuals or groups inside your organization or partner companies. These data breach threats are hard to detect. Insiders tend to possess legitimate credentials and have high trust levels. If they choose to extract and sell data, security teams may not know until it is too late.

There are two main types of insider threats. The most common variety is accidental data exposure via human error. For instance. employees may expose personal records in public places or share data with outsiders.

Deliberate data theft is less common but potentially more destructive. Unhappy employees with access to business databases could extract client data for sale to competitors or sell the information to criminal collectives.

Businesses must guard against both insider threat types to fine-tune their data breach strategy. Effective security measures include:

• Using Data Loss Prevention (DLP) tools. DLP monitors the status of critical data, logging access patterns and user actions. These tools can prevent unsafe transfers or request additional credentials to protect sensitive data.
• Training employees. Staff need to know what data exposure means and how to safely handle information.
• Managing privileges. Apply the principle of least privilege to limit access to data, and remove network access immediately when staff leave the organization.

Third-party breaches

Anyone with legitimate credentials can launch data theft attacks. This includes trusted third parties, who are often subject to supply chain attacks.

For example, the 2019 SolarWinds attack injected the Orion performance monitoring software with malware. When SolarWinds distributed Orion updates, the malicious code executed, exposing the data of 18,000 customers.

Attackers effectively turn third-party tools into backdoors. Until the supplier patches the vulnerability, criminals can extract data from compromised customers. In the SolarWinds case, hackers lurked for months on client networks, monitoring activity and stealing sensitive information.

Defending against third-party risks is tough. However, companies can manage risks with robust third-party security assessments, limiting vendor privileges, and integrating supply chain attacks into incident response plans.

Weak passwords

User credentials are a critical vulnerability when preventing data breaches. Breaches often happen when employees reuse the same password or rely on similar passwords for each account. In these cases, unauthorized individuals gain access by guessing access credentials—often based on stolen data.

However, criminals don’t need prior knowledge of user behavior. They can use brute force attacks to guess passwords. Alternatively, they might use phishing techniques to persuade users to enter their passwords into fake login portals.

There are many ways to work around password and user name login systems. Moreover, successful attackers appear trustworthy, creating a window of opportunity to extract sensitive information.

Robust network security measures are essential. Implement multi-factor authentication (MFA) for network access, which requires strong, regularly changed passwords. Threat detection systems should also monitor endpoints to detect multiple failed logins, which are often the signature of credential-stuffing attacks.

Unpatched vulnerabilities lead to preventable data breaches

Unpatched software and outdated systems are tempting targets for data thieves. The 2024 Verizon Data Breach Report found that exploits account for 14% of known data breaches. However, while that number sounds low, exploit attacks rose 180% in the previous year. As Verizon puts it, we are experiencing an “exploitation boom.”

The Equifax data breach shows how damaging exploits can be. In 2017, the credit rating giant suffered one of history’s largest breaches following an attack on outdated Apache Struts 2 servers. A simple vulnerability led to massive data breach costs, including a $425 million settlement and free credit monitoring for 150 million victims of the breach.

Keep confidential data safe by implementing a proactive patch management strategy. Automate patch delivery where possible, and audit updates to ensure internet-facing apps and devices are current. Threat intelligence can also help by alerting security teams to emerging exploits.

Cloud misconfigurations and data security failures

In today’s digital economy, about 60% of corporate data resides in the cloud. This makes cloud platforms common targets for data thieves. It also means that companies need secure cloud configurations to block unauthorized access.

For example, cloud storage buckets containing confidential information should never be directly accessible from the public internet. Encryption and segmentation should separate sensitive data from external actors, with robust access controls. However, misconfigurations can leave data buckets exposed.

Companies may secure data but forget about access management tools—making it easy to gain access and move between cloud resources. Sometimes, IT teams don’t remove obsolete cloud deployments, raising exploit risks.

Cloud security is vital. Implement MFA and attribute-based identity verification to block threat actors. Ensure critical data remains secure and isolated from the public internet, and encrypt data in transit and at rest on cloud platforms.

Physical device theft

All of the talk about exploits and ransomware attacks can be deceptive. While digital data breaches are common, physical security breaches are just as important. Companies can’t focus all of their energy on cybersecurity and forget about physical devices.

Physical data breaches involve unauthorized individuals gaining access to private network devices. Criminals might break into data centers or offices and steal devices or access applications on-site. However, data theft can also happen when employees lose work laptops or smartphones in public places.

This type of attack is common in the healthcare sector. In 2018, thieves stole the laptop of a Coplin Health Systems employee from their automobile. The device was not encrypted, allowing attackers to harvest data from 43,000 patients.

Nothing had changed by 2024, when criminals stole a TimeDoc employee’s laptop on public transport. While the device was password-protected, patient data was not encrypted.

What can you do to avoid similar incidents? Take robust security measures regarding using laptops outside work. Encrypt all sensitive data and require 2FA or MFA for work devices. That way, thieves usually won’t be able to access and sell client data.

SQL injection

SQL injection attacks target website code, allowing criminals to access application backends and confidential databases.

These types of data breaches rely on poor code management and data entry forms that fail to sanitize user inputs. Instead of blocking malicious SQL queries, forms allow attackers to bypass authentication processes or even retrieve all user records.

For example, in 2023 the ResumeLooters collective mounted SQL attacks on 65 employment websites, looting data for sale on Chinese Telegram groups. Both Sony and Marriott Hotels have also fallen victim to SQL injection in recent years, suffering significant data breaches.

Avoid similar breaches by improving your data security practices. Filter database inputs and separate databases from initial login portals. Ensure you sanitize every query to identify malicious inputs, and audit code regularly to ensure ongoing protection.

Man-in-the-Middle attacks

Our final cause of data breaches places attackers between victims and internet resources. Man-in-the-Middle (MitM) attacks intercept traffic without the victim’s knowledge, allowing them to monitor data transfers and conversations.

Attackers can track online activity, or use keyloggers to harvest login credentials and credit card numbers. They can also redirect users to fake websites that resemble trusted originals but actually contain malicious data entry forms.

MITM attacks are commonly associated with remote work. Attackers create fake Wi-Fi hotspots that seem legitimate and linked to an actual location. Connecting to these hotspots allows attackers to seize control, compromising data transfers from remote devices.

Cut Man-in-the-Middle attack risks with VPN protection

The good news about Man-in-the-Middle attacks is that encryption makes them much less effective. Attackers cannot easily understand encrypted traffic and tend to move on to other targets.

We advise using a Business VPN to encrypt web traffic at all times. Business VPNs encrypt traffic on cloud platforms and on-premises networks, while also protecting remote connections. This significantly cuts the risk of eavesdroppers using MitM techniques.

You can also strengthen security measures with Always On VPN functionality. This feature applies VPN coverage to all internet connections and cuts connectivity if the VPN drops. There are no vulnerable moments. Encryption applies consistently, across all network devices.

The real impact and cost of a data breach

The list above shows there are many ways to carry out data breaches. But what are the real-world costs of these techniques, and do they justify investing in advanced security measures? In our opinion, the stats below prove that the benefits of security easily outweigh the financial costs:

• The average cost of a data breach in 2024 was $4.88 million—up 10% from 2023 [IBM]
• In 2025, the average cost of an insider threat attack is $17.4 million, up from $16.2 million in 2023 [Ponemon]
• Exploit attacks increased by 180% from 2023-2024 [Verizon]
• Companies suffering data breaches see their sales growth fall by 3.2% and lose 1.1% of their market value [NBER]
• 60% of consumers won’t do business with companies that suffer data breaches [Chain Store Age]

How NordLayer can help with data breach prevention

Data is everything in the modern economy, where businesses rise or fall based on their capacity to collect and analyze information. However, as data becomes more valuable, it also becomes a bigger target. Data breach risks require streamlined security solutions.

That’s where NordLayer comes in.

Our Business VPN encrypts network connections, shielding data from eavesdroppers and unauthorized infiltrators—cutting Man-in-the-Middle attack risks. Meanwhile, dark web scanning tools check underground marketplaces for compromised data, enabling proactive strategies before attacks occur.

NordLayer also helps defend against phishing and malware threats. DNS filtering tools block access to malicious websites, while Download Protection detects and prevents accidental malware downloads.

To mitigate insider risks, NordLayer enables network segmentation through Cloud Firewall features, which contain potential threats within isolated environments. Zero Trust policies ensure that only authorized users can access sensitive data.

Want to strengthen your data breach defenses? Contact the NordLayer team today. We’ll help you upgrade your data security and keep sensitive information safe.