A data breach means that attackers have successfully compromised your company’s cyberdefenses and gotten their hands on some corporate data. A serious data breach could ruin your business’ reputation, let alone cost a fortune to recover from. Knowing the common ways that cybercriminals breach data security will help you keep your company’s defenses resilient to attacks.

What is a data breach?

During the third quarter of 2024 alone, data breaches exposed more than 422 million user accounts worldwide, while the cost of a data breach in 2024 reached a global average of USD 4.88 million.

You might think a data breach always has some malicious intent behind it. However, a data breach can sometimes happen due an accidental data leak or human error.

The most common types of data breaches

A data breach may easily become your company’s most expensive problem. Check out our comprehensive list of the most common types of data breaches and their causes so that you can direct your security effort toward preventing these threats.

Malware

Malware is any harmful software (program or file) that cybercriminals develop to steal data, cause damage to computers and systems, or deprive legitimate users of their access to the system or information. The number of malware attacks globally has been rising steadily since 2021, with 6.06 billion cases reported in 2023.

Though numerous types of malware can bring about a data breach, they spread in similar ways. Typically, you may catch a malware infection when you do the following:

• Download an infected file or app.
• Click on a malicious link or ad.
• Install software from unreliable sources.
• Use legitimate software that has vulnerabilities that attackers may exploit. This includes postponing software updates designed to patch up security flaws.
• Fall for a phishing attack or scam.

Let’s explore the most common and damaging types of malware.

Ransomware

Ransomware encrypts or locks data on your device and demands a ransom for the decryption key, effectively locking you out of your own system. In businesses, a ransomware infection can escalate into a corporate data breach if attackers steal sensitive information before encrypting it, threatening to expose or sell the data if you don’t pay up.

Spyware

Once spyware infects your device, it gathers information you store on it, including personal and corporate data, and sends it to the attackers. Typically operating in the background, spyware can track your browsing habits, capture keystrokes, and monitor online activities without your knowledge.

Viruses

Viruses are malicious software programs that attach themselves to legitimate files or applications, spreading and causing harm either when you execute the malicious file or executing automatically by exploiting operating system or software vulnerabilities.

Worms

Worms are self-replicating malware that spreads independently without needing a host file or program, often exploiting network vulnerabilities to infect other systems automatically.

Adware

Adware is a type of software that delivers intrusive advertisements to users. Typically, it collects data or redirects users to specific websites, often malicious.

Trojan horses

Trojan horses are a particularly sneaky type of malware that downloads onto your computer disguised as legitimate software. They are capable of stealing data and installing additional malware.

Rootkits

A rootkit is a collection of malicious software that hackers hide on your computer to reach areas otherwise inaccessible to them and to take control of your system. Rootkits operate at a deep system level, often hiding within core operating system files, making them invisible to standard security tools and able to bypass typical removal methods.

Keyloggers

Keyloggers are malicious software or hardware that secretly keep track and record your every keystroke. This way, they can capture sensitive data like passwords, messages, and credit card details.

Social engineering

Social engineering is the psychological manipulation of people to make them compromise data security. Criminals often create fake emails, ads, or websites designed to look legitimate, tricking you into revealing personal information, clicking a malicious link, or downloading harmful attachments, which may all result in a corporate data breach.

Phishing attacks

Phishing attacks are one of the most common social engineering methods that come in different forms:

• Spear phishing. In spear phishing, attackers use personalized information to target a specific person, group, or organization. They aim to coerce you into sharing sensitive information, downloading malware, or sending them money.
• Email spoofing. Cybercriminals send fake emails that appear to come from a trusted source to trick you into revealing sensitive information.
• Whaling attacks direct their effort towards high-profile companies and individuals, such as executives, to gain access to confidential corporate or client data.

SQL injection

In SQL injection, attackers inject malicious SQL code into an entry field on a website or application, tricking the database into revealing unauthorized information. This way, they are able to access, modify, or delete data, potentially compromising the security and privacy of the entire database.

Password attacks

A password attack is just what it sounds like — a hacker’s attempt to steal your password by using one or several methods described below.

Credential stuffing

Credential stuffing is the use of automated tools to try stolen username and password combinations from previous data breaches in website login forms with the goal of gaining unauthorized access to user accounts.

Password cracking

Password cracking is about trying to access a password-protected system by systematically guessing or decrypting passwords. To crack a password, attackers may use methods like brute force, dictionary attacks, or rainbow tables.

Brute-force attacks

In a brute-force attack, cybercriminals attempt all possible combinations of characters until they successfully guess the correct password. It’s an effective yet time-consuming password-cracking method.

Rainbow table attacks

Rainbow table attacks use precomputed tables of hashed password values to quickly match and reveal plaintext passwords, significantly reducing the time needed to crack them. By comparing stored password hashes against these tables, attackers can bypass the need for repetitive hashing attempts. This method is especially effective against weak or commonly used passwords.

Insider threats

Insider threats are risks posed by individuals within an organization who, intentionally or not, compromise sensitive information, security, or operations.

Data leakage

Data leakage is an exposure of confidential or protected data. An individual within an organization could intentionally or unintentionally share sensitive information with unauthorized individuals or through unsecured channels. Apart from human error, data may also leak due to software vulnerabilities or poor data security measures.

Data exfiltration

Data exfiltration is deliberate, unauthorized transfer of data from within an organization to an external destination or third party.

Advanced threats

Advanced threats are sophisticated, targeted cyberattacks designed to evade traditional security defenses and infiltrate networks undetected. These threats often employ stealthy techniques, persistence, and customized malware.

Cyber espionage

Cyber espionage is a form of digital spying. It involves the use of cyber tactics to covertly gather confidential information from governments, corporations, or individuals, often for strategic or competitive advantage. Nation-states, state-sponsored groups, and highly skilled threat actors opt for cyber espionage to target intellectual property or classified information.

Advanced persistent threats (APTs)

Advanced persistent threats are targeted, covert cyberattacks in which intruders gain unauthorized access to a network and remain undetected over an extended period. Typically, nation-states and organized crime groups conduct these highly sophisticated attacks.

Zero-day exploits

In zero-day exploits, attackers take advantage of unknown security vulnerability in computer software, hardware, or firmware. The software vendor and security community don’t yet know about these vulnerabilities, leaving no time (“zero days”) for developers to patch them, which, in turn, allows attackers to infiltrate systems before defenses can be implemented.

Supply chain attacks

In supply chain attacks, cybercriminals infiltrate an organization by compromising its external partners or third-party vendors that have access to the organization’s systems or data. For example, by targeting trusted suppliers, attackers can introduce malicious code or vulnerabilities to a target’s system or network.

Data breaches are one of the most common cybersecurity threats that businesses and individuals have to face. What may seem like a small data leak can result in huge financial loss and reputational damage. So, what is a data breach, how does it happen, and how can you safeguard your data?

What is a data breach?

A data breach occurs when unauthorized people gain access to personal, classified, or otherwise protected information. Data breaches can be unintentional (for example, resulting from a company file sent to the wrong person) or malicious (caused by phishing emails, hacker attacks, or malware infections).

More often than not, businesses and individuals suffer malicious data breaches. Since data can hold significant value, it’s natural that cybercriminals try to steal it and make a profit from it either by selling the obtained information on the dark web or ransoming it for huge sums.

How do data breaches happen?

Typical data breaches involve specific steps, such as reconnaissance, gaining access, extracting data, and covering the hackers’ tracks. In certain cases, cybercriminals can also use privilege escalation or lateral movement.

Here’s how malicious actors breach systems to steal data:

• Step 1 – Reconnaissance. Before launching an attack (be it phishing, malware, session hijacking, or brute force attacks), cybercriminals will scout the system for potential attack vectors and system vulnerabilities. Once they gather the information they need, the cyberattack is ready to go.
• Step 2 – Gaining access. This one is also known as the initial compromise. During this process, hackers use their preferred attack method to gain unauthorized access to the system and its data.
• Step 3 – Privilege escalation. Once they breach the system, malicious hackers may need higher clearance, such as admin rights, to bypass restrictions and access more sensitive data. To do so, hackers exploit system vulnerabilities until they get admin-level access, which strengthens their control over the compromised system.
• Step 4 – Lateral movement. When hackers gain enough power over the system’s controls, they can use them to move laterally across the network. That means malicious actors have open access to all or most system files, most significantly those that include sensitive information.
• Step 5 – Data exfiltration. Once the bad guys are completely set in the breached system, they begin exfiltrating the “good stuff.” Using extraction tools, hackers steal personal information, business secrets, and classified documents in seconds, sometimes before system owners can even notice anything.
• Step 6 – Covering tracks. After completing their task, the hackers will try to cover up any trace of their presence. This usually means deleting activity logs or disabling security systems so that the system owners and security do not pick up any leftovers, unusual files, or suspicious activities.

The steps above describe a perfect data breach, during which the system operators are unaware of being attacked. Depending on the type of attack, the system security, or the vigilance of its owners, data breaches can be spotted early or even during the attack, forcing malicious actors to adjust their methods.

What are the main causes of data breaches?

Poor cybersecurity practices, such as weak passwords or unpatched vulnerabilities, are usually the main causes of data breaches. Cybersecurity experts also note that human error is among the most common causes of this issue and add misconfigured systems and physical credential theft (or loss) to the list of contributing factors.

Hackers target both small and large businesses for two different reasons. Small businesses often lack robust cybersecurity practices, making them easy targets. Meanwhile, large companies often present a challenge that can motivate hackers to breach the system and humiliate the company publicly, resulting in financial and reputational damage. Some hackers may also breach systems to commit espionage or even shine a light on a specific political or social cause (a process also known as hacktivism).

Based on these simple principles, malicious actors can exploit different vulnerabilities. For example, small businesses often suffer phishing and other social engineering attacks. Big businesses aren’t immune to phishing either, due to the larger number of employees and extensive communication channels. However, they’re also more likely to experience brute force attacks, which can breach the company’s cybersecurity and result in data theft.

Businesses may also face different types of data breaches caused by insider threats (employees who willingly help hackers get inside), malware, unpatched system vulnerabilities, or even lost or stolen company devices. This is why companies invest in cybersecurity measures, such as password managers, two-factor authorization (2FA), and skilled cybersecurity personnel. However, it’s equally important to train all employees to help them understand their role in maintaining cybersecurity in the workplace.

What methods are used in data breaches?

As mentioned, hackers can use numerous methods to breach the systems and steal data. From malware to third-party software, here are the main ways in which malicious actors may launch a data breach attack:

Malware

Hackers use malware to slip into the system undetected. Files with spyware or ransomware, trojans, and infostealers are among the most common types of malware that can open doors for hackers to access your system, potentially gain admin-level privileges, and steal sensitive data.

Malware can infect your system through various methods, including phishing links, infected USBs, and unsafe websites. Therefore, employee vigilance is essential in preventing this type of cyberthreat.

Social engineering

Social engineering refers to attacks that involve direct contact between the hacker and the system user. Malicious actors create believable scenarios and try to lure users into providing sensitive information, using methods such as phishing.

Whaling is another great example of a social engineering attack. This method is used to target big companies and works similarly to phishing. During whaling attacks, hackers send emails to high-level employees (executives, CEOs, and CFOs), pretending to be representatives of reputable companies, such as law firms. In those emails, the hackers may urge their victims to wire money, share the company’s secrets, click on suspicious links, or download unknown files.

Phishing

Phishing is a social engineering cyberattack that exploits users by baiting them to click on links or files that contain viruses, spyware, and other malware. Hackers usually attempt phishing through email and contact employees with messages that create a sense of fear or urgency and encourage quick response. For example, phishers may target employees by pretending to be representatives of legitimate organizations, and prompting the users to take immediate action based on the content of the email.

If an employee takes the bait, they may click on the link which typically hosts some kind of malware, potentially opening the doors for cybercriminals to breach the system. The landing pages of some phishing links may also replicate known user interfaces, such as system login windows, and scan everything the user types (including username and password), further exposing the system to the threat.

Human error

No matter how hard people try, sometimes accidents happen. A lost keycard, a typo in the email address field, or a lost work laptop can cause a data breach if they fall into the hands of malicious actors. If something like that happens, it’s important to report the issue without ignoring it and be vigilant of potential breaches or attacks. Offering support to the person who made a mistake is also a good practice for maintaining loyalty among employees.

Insider threats

In some cases, hackers can initiate a data breach with assistance from someone inside the organization. According to the experts, this issue has become so prevalent that it now ranks among the top cybersecurity risks for large businesses. To prevent insider threats, you can limit access to sensitive information or invest in a better workplace environment (people are less likely to turn against the company when they actually like working there, right?).

Supply chain attacks

Supply chain attacks occur when hackers target part of a company’s supply chain software. In simple terms, it’s a type of cyberattack that targets service providers, vendors, and third-party apps on which the company relies. Some businesses may need to share access rights or sensitive information when using third-party services. Therefore, a successful supply chain attack can expose your company’s system even if it wasn’t attacked directly.

Unpatched vulnerabilities

As soon as companies develop new strategies to safeguard their data, malicious actors come up with new ways to overcome them. System security gets obsolete fast, exposing businesses to cyberattacks. Overdue updates and unpatched vulnerabilities invite hackers to breach your networks and steal sensitive data. To avoid such problems, companies should install system updates as soon as they launch while constantly monitoring and patching additional system vulnerabilities.

Weak or stolen credentials

Weak passwords are one of the most common causes of data breaches. Far too often, people believe their passwords are strong enough, while a hacker with a capable toolset can crack them in mere seconds. Safeguarding against this vulnerability requires businesses to introduce 2FA and educate employees on password security. Using additional tools such as password managers can also be a huge benefit.

Cloud misconfigurations

While cloud storage is a convenient choice for data storage, poorly configured cloud servers can turn that comfort into a headache in just a few seconds. Insufficient user restrictions, lack of encryption, or disabled logging and monitoring can allow malicious actors to jump into your cloud server and peek at all the sensitive data you might be hiding there.

Third-party access

Third-party access vulnerabilities can allow cybercriminals to steal your business data even without directly attacking your company. Hackers may target a third-party service provider to hijack communications, gain access to specific files shared between your company and the third-party service provider, or learn about potential vulnerabilities.

Safeguarding against this risk is difficult but not impossible. Before entrusting your company’s data to a third-party service provider, make sure that the provider has an impeccable cybersecurity record. Even then, set up separate accounts for communication and use proper information segmentation. In addition, look for ways to safeguard your system in case of a third-party attack.

What are the targets of data breaches?

Data breaches, as the name suggests, mainly target data. Depending on the service the business provides, we can divide that data into more specific types.

• Personal data. Includes names, surnames, addresses, phone numbers, Social Security numbers, and birth dates. Malicious actors may use stolen personal data to commit identity theft or sell it on the dark web.
• Financial data. This data type includes credit card numbers, bank account details, and payment information. With this data, hackers can try to carry out fraudulent transactions or drain bank accounts.
• Login credentials. If the system collects usernames, passwords, or answers to security questions, the data breach will expose them to malicious actors. Needless to say, login credential leaks can pose a huge risk of identity theft and loss of account access (for example, when hackers use the victim’s login details to change the account’s password).
• Intellectual property. Patents, trade secrets, and research data can harm businesses and cause significant financial damage when in the hands of hackers. Malicious actors may demand ransom for stolen data or try to sell it on the dark web, making a company’s hard work go to waste.
• Customer and client data. Businesses often collect various types of customer data including, but not limited to, personal and financial information. Suffering a data breach that leaks client data is a huge financial, reputational, and potentially legal blow. Customer data is often the most sought-after target for malicious actors because it causes the most damage, hurting the business and creating thousands of potential new victims.
• Government data. Some companies may work closely with the government as service contractors. That could mean exchanging sensitive information such as strategic documents, personal data of government employees, or even classified information. Exposing such data to hackers could, at the very least, cause a scandal, let alone destroy careers, or even worse — put someone’s life in danger.

We’re excited to introduce NordStellar’s latest feature – attack surface management (ASM) – designed to provide continuous visibility and assessment of your organization’s external attack surface.

“By introducing ASM, we aim to help improve our clients’ overall security posture, ensuring that their security teams are equipped with insights needed to effectively manage their attack surface, minimize exposure to external threats, and meet regulatory requirements for vulnerability assessments,” says Vakaris Noreika, head of product at NordStellar.

ASM helps security teams monitor internet-facing assets, such as websites, servers, applications, and cloud resources, while identifying and mitigating vulnerabilities before they can be exploited. By automating the discovery of security gaps, NordStellar’s ASM empowers organizations to proactively reduce cyber risks and strengthen their security posture.

Why companies have trouble managing their attack surface

Many companies lack full visibility into their external-facing assets, making it difficult to detect potential vulnerabilities that could be easily found by attackers on the dark web and exploited.

“Any security gaps in a company’s websites, servers, applications, cloud resources, or internet of things devices are a ticking time bomb, and it’s vital to identify and mitigate these vulnerabilities before attackers have a chance to act,” says Noreika.

However, many organizations still struggle with understanding and managing their attack surface due to several key challenges:

• Unidentified and unmanaged assets. Many organizations struggle to maintain a complete and accurate inventory of their internet-facing assets. Without visibility, securing unknown or forgotten systems becomes impossible, leaving critical blind spots for attackers to exploit.
• Inefficient manual processes. Traditional methods of asset discovery and vulnerability assessment often involve manual processes, spreadsheets, and disparate tools. This is time-consuming and labor-intensive.
• Difficulty prioritizing remediation efforts. With limited resources, knowing which vulnerabilities pose the greatest risk and require immediate attention can be a challenge.
• Lack of real-time threat detection. The attack surface is constantly changing, with new vulnerabilities being discovered and exploited daily.
• Shadow IT and unknown risks. Unauthorized devices, applications, or services connected to the network without IT’s knowledge (shadow IT) significantly expand the attack surface and introduce uncontrolled risks.

How NordStellar’s ASM works

NordStellar’s ASM consists of two main modules – automatic asset discovery and external vulnerability management. Automatic asset discovery maps your infrastructure by running various domain enumeration processes. This way, ASM automatically identifies and catalogs all internet-exposed assets related to your organization, such as web servers, applications, and other network-connected devices. NordStellar can also discover domains, SSL certificates, and IPs.

In the meantime, external vulnerability management continuously monitors and scans the discovered assets for known weaknesses, delivering actionable intelligence to streamline recovery efforts.

How security teams can put ASM into practice

Continuously monitoring and assessing the attack surfaces is by no means an easy task, requiring a great deal of time and human resources. NordStellar’s ASM provides value for different members of your security team:

• Security analysts. Imagine starting your day by opening the ASM dashboard, where critical internet-facing vulnerabilities – whether it’s a misconfigured server or an exposed cloud resource – are already detected. You can dive straight into investigating the highest risks, collaborating with IT teams, and implementing fixes before attackers can exploit them.
• Security engineers. Picture integrating ASM into your workflow. The platform continuously scans your external assets, uncovering weak points that could be exploited. With ASM’s automated discovery, you streamline your vulnerability patching process and address gaps while freeing up time to focus on strategic infrastructure security questions.
• Security managers. See yourself walking into a stakeholder meeting with NordStellar’s ASM reports. You can clearly demonstrate how the team has reduced the organization’s attack surface, track remediation progress in real time, and provide data-backed proof of compliance. You’re ready to show the tangible value of proactive risk reduction to the entire business.

With ASM, every member of your security team gains the tools they need to strengthen your organization’s security. From real-time monitoring to automated insights and clear reporting, ASM helps you stay ahead of threats and focus on what matters most – keeping your business protected.

Key benefits of NordStellar’s ASM

Security teams are under constant pressure to manage the attack surface: unknown assets, evolving vulnerabilities, and manual processes hamper them down and create unnecessary risk. That’s where NordStellar’s ASM comes in, providing:

• Minimized attack surface. By identifying and mitigating vulnerabilities, NordStellar’s ASM helps you reduce the chance of a successful attack.
• Enhanced shadow IT visibility. With ASM, you’ll be able to maintain an accurate list of internet-exposed assets, protecting them from unknown threats.
• Automation-driven operational efficiency. This lets you avoid manual vulnerability scanning, which is time-consuming and prone to errors.
• Real-time threat detection. Unlike traditional periodic scans that leave gaps between assessments, ASM ensures continuous monitoring and alerting.
• Mitigating vulnerabilities before attackers do. NordStellar’s ASM lets you protect your assets before threat actors can do damage.
• Meeting compliance requirements. You can use ASM to demonstrate compliance with industry regulations that require regular vulnerability assessments.
• Cost saving. With this feature, you can minimize the financial impact of security incidents.

Threat exposure is a metric that every business owner should be aware of. Some might even say that it’s the most important part of maintaining business success. With that in mind, let’s explore threat exposure — specifically, what it is, what it shows, and how companies can reduce it.

Threat exposure: What is it?

Threat exposure is the combined total of cybersecurity risks and vulnerabilities that threaten the company. It encompasses the weaknesses of every part of an organization’s IT environment, starting with the system and finishing with the third-party providers.

The importance of understanding threat exposure

Understanding a company’s threat exposure can provide insight into its security posture. Large threat exposure makes organizations vulnerable to cyberattacks and can lead to significant legal troubles along with major reputational and financial damage. Identifying vulnerabilities and implementing external attack surface management can help businesses curb the biggest cybersecurity weaknesses and reduce the chances of a successful cyberattack.

“Data is the new gold” — once just a catchy Salesforce campaign slogan, now strikes true more than ever. Protecting personal, company, and client information should be a top online priority for any business. Researching and defining effective threat exposure management strategies are the first steps in doing just that.

The dangers of ignoring threat exposure

Ignoring threat exposure in the organization is the same as ignoring the first symptoms of a disease. Eventually, both will cause serious problems. While you may not lose your life, disregarding a company’s threat exposure management can result in data breaches, brute-force attacks, and other cybersecurity incidents. Consequently, these can lead to lawsuits, fines, bad press, and operational disruptions.