How to Prevent Ransomware Attacks: Key Practices to Know About

Ransomware attacks are one of the biggest threats facing all businesses. Last year, for example, the number of attacks rose by 27 percent, according to Thales’ 2024 Data Threat Report. What’s more, 93 percent of security pros agreed that this is a growing risk.

The biggest threat within this category is attacks that exfiltrate data. Our research found this was a factor in 94 percent of cases in 2024. This can be devastating, as in addition to any downtime a firm suffers, data exfiltration can leave it exposed to a range of issues, including:

• Costly ransom payments to prevent sensitive data from being leaked
• Reputational damage, especially if sensitive customer data is stolen
• Regulatory fines
• Class-action lawsuits from affected customers

In some cases, a ransomware attack could even put a company’s future at risk. That’s why it’s so important to have effective defenses in place to prevent ransomware. Read on to learn more about the threat of ransomware and what key things companies must do to prevent it.

Step one must be for firms to ensure they have a comprehensive understanding of what these attacks involve and why they are so dangerous. This includes knowing exactly what happens during a ransomware attack, how companies get infected and what can be done to both prevent and recover from these incidents.

Ransomware is a wide-ranging term that refers to any form of malicious software (malware) that aims to disrupt a firm’s operations, with the hacker then demanding a monetary payment in exchange for restoring systems.

Traditionally, this would have involved infecting a business with a ransomware virus that sought out important files and encrypted them, rendering them unusable unless companies paid for the decryption key. This is known as crypto or locker ransomware.

However, today the most common form of this attack involves double extortion ransomware, which also aims to exfiltrate data from a business. Once hackers have this data, they can then demand further ransom payments to prevent the public exposure of sensitive information.

The most common way for ransomware to enter a business is via emails. Employees falling victim to phishing attacks, for example, can accidentally download malicious software or hand over login credentials to hackers. Criminals may also take advantage of unpatched or as-yet undiscovered software vulnerabilities to gain access to sensitive data.

Once inside a network, hackers aim to move laterally and seek out the most valuable or sensitive data to exfiltrate. This is where firms still have a chance to stop a data breach, as once attackers have successfully exfiltrated data, it will be too late.

While there are a variety of mitigation strategies businesses can turn to if they do fall victim to ransomware, the best way to protect against it is to avoid infection in the first place. This requires a strong focus on data security throughout the organization and a range of preventative techniques. Here are some of the most important ransomware protection strategies that no business should be without.

Perimeter defenses such as firewalls, email security tools and antimalware play a key role in preventing ransomware. These can’t provide 100 percent protection, especially against the most sophisticated attacks, but they are essential in setting the foundations of a solid defense.

Moreover, effective access controls are one of the best ways to prevent ransomware. Tools such as multifactor authentication minimize the risks posed by compromised credentials. This should be combined with zero trust security models and the principle of least privilege to ensure user identities are confirmed and no individual has access to more files than they need to do their job.

Employees are often the weakest part of any firm’s defenses. Estimates vary, but human error is thought to be a factor in anywhere between three-quarters and nine out of ten data breaches. This means it’s vital to focus on your workforce when planning a cybersecurity strategy.

Regular security training is a must. This should focus on how to spot common attacks such as phishing attempts, as well as reminding users of the importance of good password practices. Password managers can help employees handle these demands, while it can also be useful to test their responses with simulated ransomware attacks. These can show if individuals remember what they have been taught in real-world scenarios.

Hackers exploiting vulnerabilities in outdated software is another major cause of ransomware. To avoid this, it’s important to have a clear patch management strategy and a schedule for updating operating systems, applications and any third-party software. This can be especially challenging for large businesses with sprawling networks, so the use of automated tools to help the process can be highly beneficial.

Regular backups are essential in guarding against ransomware that encrypts or destroys files. While this doesn’t directly prevent ransomware, the more thoroughly this is done, the less disruptive an incident will be. This means firms will have less incentive to pay a ransom, making them a less tempting target for future attacks.

An essential line of defense against ransomware, advanced endpoint detection and data loss prevention not only stops hackers from entering a network but can prevent them from stealing data. Dedicated anti data exfiltration (ADX) software works by blocking unusual activity across all network endpoints, automatically shutting down any suspicious attempts to exfiltrate data. This means that even if hackers are able to breach a network, they won’t be able to escape with their prize.

Even the most effective defenses cannot guarantee 100 percent protection. While ADX solutions can be hugely helpful in preventing data theft, unless firms have the right defenses in place, there may still be opportunities for more traditional ransomware tactics such as encrypting data. This is where comprehensive backups and data recovery tools come in to assist with ransomware recovery.

Once a ransomware virus has been detected and firms need to turn to backups, it’s important there is a clear process in place to do this. Otherwise, firms may run the risk of having their newly-restored files also fall victim to attacks. There are few key steps that are vital to the success of such operations. These include:

• Ensuring all infected systems have been fully isolated
• Identifying recovery plan objectives – what critical data needs to be prioritized?
• Assigning clear roles to all team members
• Contacting relevant stakeholders or regulators

Ideally, these steps should all be spelled out in a pre-existing disaster recovery plan that has been drafted and tested prior to any incident. If firms don’t have such a document and are taking an ad hoc approach, this greatly increases the chances of errors being made.

Businesses cannot rely solely on traditional defenses such as antimalware tools to protect against ransomware. Instead, they must take a proactive approach that emphasizes continuous updates, effective communication with employees and specialist ransomware solutions such as ADX to address the ever-evolving threat.

Key ransomware prevention tips to remember include:

• Have a ransomware response plan: This should detail what immediate actions should be taken and who will be responsible for what steps.
• Conduct regular security audits: Efforts such as penetration testing and network monitoring can alert firms to any vulnerabilities they may have.
• Enforce strong access controls:  Implementing role-based access control (RBAC), limiting admin privileges and removing unneeded credentials are all important aspects of this.
• Keep up with emerging threats: Following the latest bulletins from the likes of CISA, NCSC and other cybersecurity reports help firms stay ahead of new ransomware tactics.