Types of Data Breaches and Prevention Steps

Preventing data breaches is one of the biggest challenges facing any firm. The consequences of these incidents can be severe, both reputationally and in financial terms. For instance, it’s estimated that in 2024, the average data breach incident cost almost $4.9 million.

To avoid these risks, it’s vital that you have a clear prevention plan in place. However, ‘data breach’ is a wide-ranging term, covering everything from mis-sent emails and lost phones to large-scale, state-sponsored hacking attacks. Therefore, having a full understanding of the breadth of the problem and the steps you should take to counter the different threats is critical.

Examples of major data breaches in 2024 include attacks on Change Healthcare, the NHS and Starbucks. Read on to find out how you can avoid adding to the list in 2025.

In order to prevent data breaches, it’s important to understand the methods hackers use to gain access to businesses, and the different ways data exfiltration can take place. There are many ways in which incidents can occur, and not all of them involve external attacks that can be spotted by traditional cybersecurity methods.

Therefore, familiarizing yourself with the most common data breach attack vectors is an essential first step in protecting your most sensitive information. Here are some of the most common types and key prevention measures.

A wide-ranging term, malware is a catch-all phrase that can refer to any type of malicious software hackers seek to infect a network with. This can then be used by cybercriminals to gain unauthorized access to confidential information, exfiltrate data, disrupt systems, spy on a user’s activities or delete data on the network. 

The most common way for malware to enter a network is via a phishing attack, which is the root cause of over 90 percent of incidents. These may invite users to open a file directly in order to inject malicious code, or lead them to a website that can use a drive-by download to infect a system. However, other attack vectors take advantage of software vulnerabilities, compromised websites, malvertising or the use of stolen credentials.

Effective antimalware tools are the primary way to prevent these incidents. These typically work by analyzing data entering a system for key signatures of known malware, or monitoring the behavior of files for suspicious activity. However, these methods aren’t foolproof, so should only be one part of a holistic cybersecurity solution.

Getting more specific, ransomware is a particular type of malware that has become one of the most popular forms of cyberattack over the last few years. Indeed, according to Sophos, almost six out of ten businesses (59 percent) were targeted by ransomware in 2024.

The nature of these attacks has also changed. Traditionally, a malicious actor seeking a ransom would encrypt data or systems, preventing mission-critical business activities from taking place. They would then demand money in exchange for the decryption key needed to recover compromised data.

However, today, by far the most dangerous threat is double extortion ransomware. This type of ransomware attack also infiltrates key business or customer data and then threatens to release it publicly if a ransom is not paid. According to our research, 94 percent of all ransomware attacks in 2024 involved data exfiltration, a nine percent rise on the previous year.

Not all data breaches originate from outside an enterprise. In fact, according to Cybersecurity Insiders’ 2024 Insider Threat Report, 83 percent of organizations reported that at least one attack in the last year came from within the business.

Insider threats can either be down to human error, such as an individual emailing sensitive information to the wrong recipient, or be intentional.

A malicious insider threat can do huge damage and be particularly hard to spot. Such individuals often know exactly what data will be the most valuable, how to access it, and how to cover their tracks and evade standard security measures. The motivations for this can vary, from retaliation for a perceived slight to blackmail or bribery. 

Technology such as access management tools and anti data exfiltration (ADX) software can be highly useful in preventing these threats, as they can detect unusual behavior within the business and block any attempt to exfiltrate business or personal information as it occurs.

As well as being used as a channel to directly deliver malware, emails can pose a range of other risks. These include targeted spear phishing attacks that are tailored to an individual victim, fake business emails that appear to be from trusted contacts such as suppliers or executives, and other social engineering attacks.

It’s estimated that over three billion phishing scam emails are sent around the world every day, which makes a strong email security solution an essential first line of defense in data breach prevention. This should be used in conjunction with other solutions such as multifactor authentication, which can prevent an attacker from using login credentials they’ve acquired via phishing to access business or customer data.  

The other critical defense against email-based threats is employee training. Firms can greatly reduce their risk by ensuring everyone in the organization is aware of the threats that arrive in their inboxes and knows what telltale signs to look for to determine if a message is genuine.

Finally, there are also data breaches that may not come from a hacker, but from more traditional criminal activities. Lost or stolen devices remain a common source of data breaches and can cause major headaches to businesses, particularly when confidential data is being handled on portable endpoints such as smartphones.

Clear policies to remind employees of their responsibilities when handling company data are important in minimizing these risks, but tools that can remotely wipe data from company-owned devices are also essential. However, these may not always be in place if workers are using their personal devices, so it’s vital you have visibility into every endpoint that may hold company data.

Preventing data breaches from happening in the first place is the best form of defense against these attacks. There are a range of tools and technologies you can put in place in order to do this, including:

• Advanced firewalls
• Email security systems
• Antivirus and antimalware tools
• Strong access control such as multifactor authentication
• Effective employee training

These steps are also vital in ensuring that you remain compliant with relevant data protection and privacy regulations. Every firm is likely to have responsibilities under general legislation such as GDPR and CCPA, which includes designating a controller for data and having clear policies in place for how information is encrypted, accessed and shared. However, companies in certain industries, such as financial services and healthcare, have even stricter rules they must follow.

However, such preventative solutions alone can never be 100 percent effective, so it’s also important to have tools that can monitor activity within the network in order to spot breaches that have already occurred.

There are several common causes and issues that can lead to data breaches. Understanding the potential consequences of these failures is crucial for hardening systems and preventing unauthorized access.

One of the biggest causes of data breaches is careless or negligent behavior by employees. This can cover a wide range of actions, but some of the most common issues include:

• Responding to phishing emails
• Misplacing devices such as laptops or smartphones
• Using easily-guessed or repeated passwords
• IT staff misconfiguring software or leaving default configurations and passwords in place

Failing to ensure all applications and resources are updated to the latest versions is another frequent cause of issues. Unpatched systems can allow hackers to take advantage of known vulnerabilities in order to gain access to a network and steal data. Indeed, 32 percent of ransomware attacks are reported to start with an unpatched vulnerability.

Failing to effectively manage access to sensitive files can make data exfiltration easy for hackers or malicious insiders. Common issues include failing to implement multifactor authentication to guard against stolen credentials and assigning too many privileges to user accounts, which can allow users to view and edit sensitive documentation they don’t need to access.

Even the best perimeter defenses can’t stop all threats, so it’s critical to have a solution that can monitor activity within your network and spot key signs of intrusion and data exfiltration before it’s too late.

Tools such as automated monitoring solutions and anti data exfiltration (ADX) play a key role in this, as they can proactively hunt out threats and shut down any attempts to steal data before it leaves the network.

 Key warning signs that these tools can look out for include:

• Repeated attempts to access databases
• Unusual editing of filenames or content
• Large file transfers
• Activity outside of normal working hours
• Connections to unknown IP addresses, especially ones based overseas

If all else fails and you’re unable to contain a data breach, there are several steps that must be taken. While it will be too late to mitigate all the damage – which is why prevention is better than cure – there are still a few key actions that can stop the incident spreading and minimize your exposure to additional expenses and future threats.

Step one: Identify the source of the breach

It’s essential to find out as soon as possible where on your network the data leak is coming from, whether it’s malware, a stolen device or a malicious insider using their own terminal.

Step two: Isolate infected systems

Once the source has been identified, it’s essential that it and any other infected system is isolated from the rest of the network, including physical cables and wireless, to prevent any further spread. 

Step three: Understand exactly what was compromised

You need a complete picture of all compromised data, as particularly sensitive information may require additional reporting.

Step four: Notify all relevant parties

Many businesses’ first instinct may be to keep a breach quiet for fear of adverse publicity, but this is a major error. Regulations such as GDPR have mandatory reporting requirements for the loss of certain data, while affected users – which may be customers, employees or partners – must be informed so they can take their own precautions.

Step five: Investigate what happened

Understanding what went wrong and how systems were compromised is essential in preventing future attacks. Many firms hire third-party investigators, as well as bringing in law enforcement, to determine a timeline of events and identify where the weaknesses lay.