18 Types of Malware and Cyber Attacks That Could Hit You in 2027

Cyber threats are constantly evolving, but many of the attacks businesses face in 2027 will build on familiar techniques. The difference is how quickly attackers can adapt, how convincingly they can impersonate trusted people and organisations, and how effectively they can exploit weaknesses across increasingly connected IT environments.

Artificial intelligence (AI) is expected to make elements of cyberattacks more efficient, from identifying vulnerabilities to creating convincing phishing messages. The UK’s National Cyber Security Centre (NCSC) has warned that AI could increase the volume and impact of cyber intrusions, while making it harder for organisations to keep their defences up to date.

For businesses, the challenge is not simply to recognise the latest malware. It is to understand how different threats work, where vulnerabilities exist and what happens when an attacker gets through.

Here are 18 types of malware and cyberattacks businesses should understand as they prepare for 2027.

1. Ransomware

Ransomware prevents organisations from accessing their files or systems, typically by encrypting data and demanding payment for its recovery. Some attackers also steal sensitive information before locking systems, threatening to publish it if the victim refuses to pay.

The impact can extend far beyond IT, disrupting operations, delaying services, affecting customers and creating significant recovery costs.

How to reduce the risk: Maintain tested, protected backups, apply security updates promptly, implement multi-factor authentication (MFA) and ensure endpoint and network monitoring can identify suspicious activity.

2. Phishing

Phishing uses fraudulent emails, messages or websites to trick people into revealing credentials, downloading malicious files or transferring money. Messages may imitate suppliers, colleagues, banks or trusted service providers.

AI-generated content can make these communications more convincing, reducing the spelling and grammar mistakes that once helped people identify scams.

How to reduce the risk: Combine user awareness training with email security, strong authentication and clear procedures for verifying unusual requests.

3. Spear Phishing

Unlike broad phishing campaigns, spear phishing targets a specific individual, team or organisation. Attackers may research their target’s role, suppliers, projects and relationships to make a message appear legitimate.

A finance director might receive a convincing payment request, while an IT administrator could be sent a fake security notification designed to capture privileged credentials.

How to reduce the risk: Restrict privileged access, verify sensitive requests through a separate communication channel and use security controls that identify suspicious links, attachments and sender behaviour.

4. Business Email Compromise (BEC)

Business email compromise involves criminals impersonating executives, employees or suppliers, or taking control of legitimate email accounts, to manipulate payments or obtain sensitive information.

Unlike many malware attacks, BEC can succeed without installing malicious software. A convincing message and a poorly verified payment request may be enough.

How to reduce the risk: Introduce independent payment verification, strengthen email authentication, protect accounts with MFA and monitor for unusual login activity or changes to supplier bank details.

5. Trojans

A Trojan disguises itself as legitimate software, a useful file or a trusted application. Once installed or executed, it may give an attacker access to a device, steal information or download additional malicious tools.

Trojans can be used as an entry point for more serious attacks, including ransomware and data theft.

How to reduce the risk: Restrict software installation, use reputable sources, apply application controls where appropriate and monitor endpoints for suspicious behaviour.

6. Spyware

Spyware secretly collects information about a user or organisation. Depending on its capabilities, it may monitor activity, capture credentials, gather files or transmit sensitive information to an attacker.

For businesses handling commercially sensitive data, customer information or intellectual property, spyware can create substantial financial and reputational risks.

How to reduce the risk: Use endpoint protection, control application permissions, investigate unusual device behaviour and restrict access to sensitive information.

7. Information-Stealing Malware (Infostealers)

Infostealers are designed to collect valuable information from compromised devices, including saved passwords, authentication tokens, browser data and cryptocurrency credentials.

Stolen information can be sold or used to access business systems. In some cases, criminals may use valid credentials to bypass perimeter defences and move deeper into a network.

How to reduce the risk: Use MFA, preferably phishing-resistant authentication for high-risk accounts, secure password management and endpoint detection and response (EDR). Revoke compromised sessions and tokens promptly.

8. Remote Access Trojans (RATs)

Remote access Trojans give attackers covert control over an infected device. Depending on the malware, this may allow them to execute commands, access files, monitor activity or install additional tools.

Unauthorised remote access can provide a foothold for further intrusion, particularly where the compromised device has access to shared systems or privileged accounts.

How to reduce the risk: Restrict remote access, enforce strong authentication, monitor endpoint activity and investigate unexpected remote-control software or connections.

9. Worms

Worms are malware that can spread between systems, often by exploiting vulnerabilities or taking advantage of weak security configurations. Unlike traditional viruses, worms do not necessarily need a user to run an infected file on each device.

In a poorly segmented network, an outbreak can spread quickly and disrupt multiple systems.

How to reduce the risk: Patch vulnerable systems, disable unnecessary services, segment networks and monitor for unusual traffic or rapid propagation between devices.

10. Botnets

A botnet is a collection of compromised devices controlled by an attacker. These devices may be used to launch distributed denial-of-service (DDoS) attacks, send spam, distribute malware or support other criminal activity.

Business routers, internet-connected devices and poorly secured infrastructure can all become targets.

How to reduce the risk: Secure device configurations, change default credentials, update firmware, monitor network traffic and isolate devices that do not need direct access to business systems.

11. Fileless Malware

Fileless attacks use legitimate system tools, scripts or memory-based techniques to carry out malicious activity while reducing reliance on conventional files stored on disk.

Because these attacks can make use of trusted processes, they may be harder to detect using security controls that focus primarily on known malicious files.

How to reduce the risk: Use behavioural endpoint detection, restrict scripting and administrative tools where appropriate, apply least-privilege access and monitor suspicious activity across endpoints.

12. Rootkits

Rootkits are designed to conceal malicious activity and, in some cases, maintain privileged access to a compromised system. They may interfere with normal operating system functions or hide files, processes and other signs of compromise.

Their ability to evade visibility can make investigation and remediation particularly difficult.

How to reduce the risk: Keep systems updated, use security controls with visibility into suspicious system behaviour and follow trusted incident-response procedures if a deep compromise is suspected.

13. Cryptojacking

Cryptojacking occurs when an attacker uses a device or cloud resource to mine cryptocurrency without the owner’s permission. The activity can consume processing power, increase cloud costs and degrade the performance of business applications.

Although it may not encrypt files or steal information directly, it can indicate that an attacker has already gained unauthorised access.

How to reduce the risk: Monitor CPU and cloud resource usage, investigate unexpected performance changes, secure cloud configurations and remove unauthorised software or processes.

14. Distributed Denial-of-Service (DDoS) Attacks

A DDoS attack overwhelms a website, application or network service with traffic or requests, making it difficult or impossible for legitimate users to access it.

For businesses that rely on online transactions, customer portals, remote working or connected operational systems, disruption can have immediate commercial consequences.

How to reduce the risk: Consider DDoS protection, traffic filtering, resilient network architecture and response plans that identify critical services and escalation routes.

15. Zero-Day Exploits

A zero-day exploit takes advantage of a software or hardware vulnerability for which an effective fix is not yet available or, depending on usage, before a patch can be applied. These attacks can be particularly challenging because defenders may have limited time or information to respond.

Not every zero-day attack is highly sophisticated, but an exposed, vulnerable system can provide an attacker with a valuable route into an organisation.

How to reduce the risk: Maintain an accurate asset inventory, reduce unnecessary exposure, apply mitigations as soon as they become available and use layered detection and response controls. No single security product can guarantee protection against every zero-day.

16. Supply Chain Attacks

Supply chain attacks exploit trust in a third-party supplier, software provider, service partner or technology component to reach other organisations.

An attacker may compromise a supplier’s environment, tamper with software or abuse a trusted connection. This means an organisation’s security depends partly on the systems and access it shares with others.

How to reduce the risk: Assess supplier security, limit third-party permissions, review integrations, monitor external access and maintain an up-to-date inventory of critical dependencies.

17. Credential Stuffing and Password Attacks

Credential stuffing uses usernames and passwords stolen from previous breaches to attempt access to other services. It relies on people reusing credentials across multiple accounts. Other password attacks may involve guessing weak passwords or using automated attempts to compromise accounts.

Successful account compromise can give attackers access to email, cloud applications, remote access services and sensitive business data.

How to reduce the risk: Enforce MFA, encourage unique passwords, use password managers, apply rate limiting where appropriate and monitor for suspicious authentication patterns.

18. AI-Enabled Social Engineering and Deepfake Fraud

AI can help attackers create convincing messages, imitate writing styles, clone voices or generate realistic video impersonations. These techniques can support fraudulent payment requests, impersonation of senior leaders, credential theft and other forms of social engineering.

The risk is not that every AI-generated message will be sophisticated or that every deepfake will fool its target. It is that attackers can use these tools to scale and personalise familiar fraud techniques.

How to reduce the risk: Establish clear approval processes for payments and sensitive changes, verify unusual requests independently, secure access to sensitive systems and educate staff about impersonation risks across email, messaging, voice and video.

How can businesses prepare for cyber threats in 2027?

Understanding these 18 threats is a useful starting point, but a list alone cannot protect an organisation. Different businesses have different risk profiles, technology environments, compliance obligations and levels of internal security expertise.

A more effective approach starts with the fundamentals.

Identify vulnerabilities before attackers do. Regular vulnerability assessments, prioritised remediation and secure configuration help reduce the opportunities available to attackers. Focus on weaknesses that are exposed, exploitable and relevant to critical business systems.

Protect identities and endpoints. Strong authentication, least-privilege access, endpoint protection and monitoring can help prevent compromised accounts or devices from becoming a wider incident.

Improve visibility across the network. Firewalls, network monitoring, segmentation and appropriate detection and response capabilities help organisations identify suspicious activity and limit its spread.

Prepare to respond. Tested backups, incident-response procedures and clear responsibilities can reduce disruption when an attack succeeds. Recovery planning should cover business operations as well as technical restoration.

Review how AI is being used. Understand which AI tools are approved, what information they can access and how they connect to business applications. Secure implementation matters as much as the security of the underlying network.

Prioritise based on business risk. Not every vulnerability or threat requires the same response. Security decisions should reflect the potential impact on operations, data, customers and regulatory obligations.

Build a security strategy around your business, not just the threats

The cyber threat landscape in 2027 will not be defined by one new type of malware. It will be shaped by how established attacks evolve, how attackers exploit gaps between security controls and how quickly organisations can identify and respond to suspicious activity.

ANSecurity helps businesses assess their security posture, identify vulnerabilities and strengthen their networks through practical, vendor-agnostic advice and implementation support. With nearly 25 years of experience, we work alongside internal IT teams to develop security approaches that reflect each organisation’s environment, priorities and budget.

Whether you need a security review, vulnerability management, network protection or improved detection and response, the starting point is understanding where your business is exposed and what to address first.

Want to understand where your organisation could be vulnerable? Contact ANSecurity to discuss your security priorities and identify practical next steps.