The biggest cyber security threats to watch for in 2026

The huge disruption and financial fallout from cyber-attacks on big brands like Marks & Spencer and Jaguar Land Rover in 2025 show how damaging such hacks can be. 

But it’s not just major brands that find themselves in the sights of cyber criminals: any business can be targeted. Nearly half of all UK businesses (43%) reported having experienced a cyber security breach or attack in the 2025 Cyber Breaches Survey from the Government.

This article looks at some of the most common types of attack, how they are changing, and simple steps to avoid falling foul of them.

1. Phishing 

By far the most common cyber-attack on businesses is social engineering. This entails employees being tricked or manipulated into revealing confidential business information or taking actions that compromise security.
 
Principle among these attacks is phishing, which is using fraudulent emails, texts or calls to deceive victims. This is very common: 93% of UK businesses suffered phishing attacks in the space of a year, according to the 2025 Cyber Breaches Survey.

Generative AI can turbocharge these attacks, helping perpetrators to both personalise and scale up their strikes. You may, for example, have noticed it’s increasingly hard to distinguish between real and fake emails designed to lure you into following a fraudulent link. 

First steps for businesses to prevent phishing attacks include:

• Ensure multi-factor authentication (MFA) is used throughout your business
• Train staff regularly using realistic phishing simulations 

2. Denial of service attacks

Denial of service attacks are aimed at slowing or take down your company’s website, applications or services.

As with phishing, attacks of this type are getting larger, more complex and cheaper to perpetrate. Researchers have warned that the use of AI assistants and chatbots means even criminals lacking technical expertise can now wage effective denial of service attacks.

First steps for businesses to prevent denial of service attacks include:

• Use denial of service protection services from hosting or network providers and enable traffic monitoring by default
• Create a denial of service attack response plan. This should include who you would contact in the event of an attack and how you would keep customers informed

3. Malware and ransomware

Malware is any kind of malicious software that can damage computer systems, networks or devices. 

There has been a proliferation of so-called Malware-as-a-Service, in which malware developers package up their tools so other criminals can use them.

Ransomware is one type of malware, which is used by hackers to seize control of data and demand a ransom (usually in a cryptocurrency such as Bitcoin) to unlock your computer or access your data. Although, even if you pay the ransom, there is no guarantee that you will have your access restored. Often it isn’t.

Successful attacks can cause significant financial losses, huge disruption and reputational damage. Many high-profile attacks that have made news headlines have involved ransomware, such as the 2025 attack on Marks & Spencer.

The tactics used by cybercriminals are rapidly evolving and malware attacks are getting more complex, especially as criminals take advantage of AI to make their attacks more effective: in a recent study by researchers at MIT, 80% of ransomware attacks they examined had used AI. 

First steps to prevent malware attacks include:

• Keep all systems patched automatically and restrict admin privileges to only those employees who need them
• Maintain offline, tested backups and plan in advance how you would recover from an attack without paying a ransom

4. Data breaches

A data breach involves criminals gaining access to sensitive information, such as customer records, intellectual property or financial information. Major UK data breaches have targeted the likes of Dixons Carphone, Equifax and Morrisons.

Like other types of attacks, a breach can cause major disruption, significant financial loss and reputational damage. 

Again, the growth of AI is adding to the challenge. Use of AI can make data security more challenging when it comes to data breaches, as a single mistake or manipulation could trigger a breach.

First steps to prevent data breaches include:

• Apply the principle of least-privilege access, meaning staff and systems only see the data they actually need
• Prepare an incident response plan that includes breach assessment, notification timelines and engagement with the Information Commissioner's Office (ICO)

5. Misinformation campaigns

Misinformation (sharing wrong data) and disinformation (purposefully falsified information) campaigns have become a significant cyber risk for businesses. 

Often spread through social media platforms and online media, such campaigns are used to inflict financial and reputational damage. 

AI makes this easier too. Attackers can generate fake audio, video or images that is almost indistinguishable from real ones. They can impersonate senior executives to authorise payments, disclose sensitive information or override internal processes. 

First steps to prevent information manipulation and interference include:

• Put in place strong identity verification for senior business leaders and sensitive requests, especially where AI tools are used
• Train staff to question unexpected messages, deepfakes or urgent requests in which attackers aim to bypass normal processes

6. Supply chain attacks

It’s not just your own internal systems that are exposed to cyber risks. Vulnerabilities in your supply chain can also impact on your business.

In fact, increasingly complex supply chains means that businesses are becoming more vulnerable to attacks that start with their partners.

As a result, the National Cyber Security Centre, the UK’s cyber security agency, is encouraging businesses to take greater action to stem supply chain vulnerabilities – something it notes few organisations actually do. 

It is asking business leaders to ensure procurement and information security teams to embed Cyber Essentials (the government-backed scheme for protection against common attacks) both within their own systems and across their supply chains. 

First steps to prevent supply chain attacks include:

• Require your suppliers to meet baseline security standards, including Cyber Essentials, as part of procurement
• Regularly review supplier access and risks, especially for IT providers with system or data access