How to Prevent Ransomware from Affecting Your Network

Cybersecurity incidents are set to be the number one threat to businesses in 2025. That’s according to a recent survey by insurer Allianz, which found 38 percent of firms ranked this as a top priority, placing it ahead of issues such as business interruption, natural disasters and changes in legislation for the potential impact it can have on operations.

Within this category, the top cyber risk for most firms will undoubtedly be ransomware. The UK government, for instance, describes this as “the greatest of all serious and organized cybercrime threats, the largest cybersecurity threat, and … a risk to the UK’s national security”.

Therefore, it’s imperative that every business has a strong understanding of the dangers ransomware poses and the best practices they must have in place to prevent it.

Ransomware works by infiltrating networks and encrypting and exfiltrating sensitive business data. Criminals then demand payment in order to restore access to data, or to prevent it being sold or released publicly online. 

There are numerous ways in which hackers can gain access to networks, but the most common is via email. Phishing attacks that trick users into downloading malicious software or handing over login credentials that criminals can then exploit are often the easiest way to bypass defenses.

These techniques usually rely on the carelessness of the recipient. Employees failing to spot telltale signs of phishing is one of the biggest causes of ransomware infections, so ensuring they are well-educated about what to look for and how to respond to suspicious emails is an essential part of preventing ransomware attacks.

However, this is not the only way criminals can attack businesses. Taking advantage of unsecured remote access, poor password management or drive-by downloads can all inject ransomware into a network.

Even the most effective perimeter solutions cannot guarantee they’ll stop 100 percent of attacks. Therefore, it’s important to have tools within the system that can look for suspicious network activity which may be a sign first lines of defense have been breached.

Among the common signs that firms should be looking out for are:

• Unusual network activity: This includes high volumes of data transfers or traffic taking place outside of working hours.
• Unexpected system behavior: Poor system performance, increased utilization of CPU resources, antimalware tools being disabled or filenames or extensions being modified may all indicate an attack in progress.
• Unauthorized access requests: Firms should monitor networks for repeated failed attempts to log in to databases, the use of multiple credentials entering the same systems or employee accounts editing files outside their remit.

It’s critically important to take a proactive approach to ransomware detection in order to shut down attacks before they have a chance to exfiltrate data from the network. To do this, a holistic approach is required. Here are a few essential best practices to include in a cybersecurity strategy.

Ensuring that only authorized personnel have access to key files is an essential step. This means using multifactor authentication to reduce the risks posed by stolen credentials, as it requires employees to have a separate form of verification – usually something held on their person that hackers won’t be able to access.

At the same time, it’s important to operate on the ‘principle of least privilege’. This means ensuring that every user account is restricted only to viewing and editing files that are required for genuine work tasks. Many organizations may seek to take shortcuts by giving users greater access than they really need as this is simpler to set up. However, this can mean that even a single compromised account could have enterprise-wide repercussions.

It’s important that all defenses are regularly tested to ensure no new vulnerabilities have been introduced – for example when new software or users are added to the network. It can often be difficult for IT teams to get an objective view of their own network, so it pays to have outside help.

External ethical hackers and penetration testers are invaluable in this, as they will use the same techniques as real hackers to try and gain access to a network, then provide a detailed report on any weaknesses they find. This can then be used to ensure secure network configurations and improve cyber hygiene.

An intrusion detection system (IDS) is a must-have for spotting threats that have already successfully breached the perimeter. A good solution should be able to monitor all activities across the network looking for suspicious behavior, log all potential incidents and automatically send alerts to cybersecurity professionals for closer investigation.

Many threat detection solutions, such as IDS systems or anti data exfiltration (ADX) solutions, can benefit from the integration of advanced artificial intelligence (AI) solutions. This can enhance protections in a number of ways, but one key benefit of this technology is that it allows firms to move away from reactive signature-based detection methods and instead look more closely at user behavior. For example, machine learning can help to build a picture of normal activity, making it easier to quickly spot any anomalies.

Effective cybersecurity can be impossible for all but the largest and best-resourced firms to achieve on their own, so partnering with experienced managed security service providers (MSSPs) is hugely helpful in safeguarding data from ransomware. Such firms can provide access to advanced technology and expertise to ensure that businesses are able to keep up with whatever emerging threats and innovations are yet to come in the sector.

The best defense against ransomware is prevention. But 100 percent security is impossible, so knowing what to do in the event you do discover an attack in progress is essential in limiting its spread throughout your network and minimizing the damage.

The first step must be to isolate any infected systems from the rest of the network. This means disconnecting them from all other systems, including switching off Wi-Fi and physically removing any cabling. However, devices shouldn’t be shut down unless it is otherwise impossible to remove their network connections, as this can destroy crucial evidence of the attack that may be stored in volatile memory.

Many firms may find they don’t have the right expertise in-house to analyze and effectively recover any lost data. Once systems have been isolated, it can be highly useful to bring in outside experts to assist with this. Such moves may not be the cheapest options, but it can minimize downtime and lost data, as well as help businesses harden their networks against future attacks.

An effective anti-ransomware plan must also ensure networks are protected against any future developments, such as as-yet undiscovered vulnerabilities and evolving attack methods. To do this, it’s important not to rely too heavily on traditional signature-matched techniques, which is an inherently reactive approach.

Advanced technology such as AI can help businesses use behavioral analysis to monitor network activity and automatically alert cybersecurity pros to any suspicious activity. Incorporating this into tools such as ADX means that any attempts to exfiltrate data can be shut down before they have a chance to succeed. What’s more, this can happen at greater speeds than would be achievable through a human response.

Having this as part of an incident response plan also protects against threats that may not be picked up by legacy methods, such as fileless malware and social engineering attacks, making it essential for tackling whatever the future of ransomware has in store.