What Is Ransomware, How It Works and How to Protect Your Business

Cybersecurity is a major worry for businesses right now, and the threat is only growing. According to the UK Government’s latest Cyber Security Breaches Survey, around 43% of all UK businesses experienced a breach or attack in 2025.

One of the most concerning trends is the rise of ransomware attacks, which the report found have significantly increased between 2024 and 2025 – affecting an estimated 19,000 businesses in the last year alone.

Here, we’ll run through the basics around what ransomware is, how it works and why it’s a serious threat to your business. Plus, how to protect your organisation and reduce the risk of ransomware and other cyber attacks.

What Is Ransomware and Why It’s a Growing Threat

Ransomware is a type of malicious software (malware) designed to block access to systems, files, or networks until a ransom is paid – usually in cryptocurrency. It has evolved rapidly over the last few years, moving from relatively simple attacks targeting individuals to highly sophisticated operations aimed at larger businesses, public services and critical infrastructure.

What makes ransomware particularly dangerous right now is its scale, speed, and sophistication. Cybercriminals now operate like organised businesses, offering ‘ransomware-as-a-service,’ where ready-made tools are sold or leased to other attackers. This has lowered the barrier to entry and dramatically increased the number of attacks.

If all that wasn’t worrying enough, there’s also the fact that many attacks now involve data exfiltration. This means that hackers don’t just lock your files and demand a ransom to unlock it – they also steal sensitive data and threaten to leak it publicly if you don’t pay the ransom.

This adds reputational damage and regulatory risk on top of operational disruption.

What Is a Ransomware Attack and How It Happens

The first step to protecting your company against ransomware attacks is to understand how they happen, and know the first warning signs to look out for.

A ransomware attack is typically a sequence of carefully planned steps, which go something like this:

Initial access – attackers enter via phishing emails, stolen credentials or software vulnerabilities
Foothold and escalation – they install tools and gain higher-level (admin) access to control systems
Reconnaissance – the network is mapped, in order to find valuable data, backups and weak points
Lateral movement – the attacker spreads across multiple devices and servers
Security evasion – defences like antivirus or backups may be disabled
Data exfiltration – sensitive data is often stolen for added leverage
Encryption and ransom – files are encrypted, systems are locked, and a ransom demand is issued.

After the ransom demand, the business must contain the attack, assess the damage, and decide whether to pay or recover from backups. The most difficult step is deciding whether or not to pay the ransom – this is a complex decision involving legal, financial and ethical considerations, especially since payment doesn’t guarantee full data recovery.

What Does Ransomware Do to Businesses?

A ransomware attack can have serious consequences for organisations of all sizes, and in all industries. It’s particularly bad for any company which holds sensitive data, such as in the financial sector for example.

The typical impact involves:

Operational downtime – systems become inaccessible, halting business activities
Financial losses – this includes ransom payments, recovery costs and lost revenue
Data loss or exposure – sensitive customer or company data may be stolen or leaked
Regulatory penalties – especially if personal data is compromised
Reputational damage – loss of trust from customers, clients and partners.

For some more vulnerable organisations such as small businesses or charities, the damage can even be severe enough to threaten long-term viability. This is why cybersecurity for SMEs is so crucial, even if it does mean an initial or ongoing investment.

How Does Ransomware Work Once Inside Your Network?

Once inside your network, ransomware typically operates quietly at first. This likely means that it remains undetected, working stealthily behind the scenes until the attacker is ready to issue their ransom demand.

It can spread across systems, gaining higher access and identifying valuable data and backups.

Many attacks also involve stealing sensitive information before triggering encryption, at which point files are locked and a ransom demand is issued, often catching businesses off guard.

At this point of course, it’s too late to carry out any defensive or preventative measures. This is why ransomware attacks are so dangerous.

How to Protect from Ransomware and Reduce Risk

While no organisation is completely immune from ransomware attacks, there are proven steps that cybersecurity experts recommend to significantly reduce your risk. These include:

Train your staff

Human error is one of the biggest entry points for cyber criminals, whether it’s clicking a link or opening a bogus email. Regular cybersecurity awareness training helps employees spot phishing attempts and suspicious activity, so they don’t inadvertently let attackers in.

Use strong access controls

Implement multi-factor authentication (MFA) and ensure users only have access to the systems they need.

Keep systems updated

Patch software and operating systems regularly to close known vulnerabilities.

Maintain secure backups

One of the strongest defences against ransomware attacks is maintaining secure and regular backups. If you have untouchable backups, you can restore your systems and data without needing to pay a ransom – this takes away much of the attacker’s power and leverage over their target.

Monitor your network

Use security tools to detect unusual behaviour early – before an attack escalates.

Segment your network

Limit how far an attacker can move if they gain access to one part of your system.

Create an incident response plan

Know exactly what steps to take if an attack occurs, including communication and recovery processes.

What Is BullWall and How It Stops Ransomware Spreading

One of the solutions we implement for our clients here at Avoira is BullWall. It’s a cybersecurity solution specifically designed to contain ransomware attacks in real time and prevent them from spreading across your network.

Unlike other tools that focus on detection, BullWall works by automatically isolating infected devices the moment suspicious encryption activity is detected. This rapid response helps stop ransomware before it can impact multiple systems or critical infrastructure.

This means immediate containment of infected endpoints, prevention of lateral movement by the attacker, and minimal disruption to the rest of your network.

To find out more about our cyber security solutions for your organisation, get in touch with our expert team here at Avoira.