What Is a Cyber Attack? 6 Common Types and How to Prevent Them

A phishing email, a stolen account, or an unpatched vulnerability can all become the starting point of a cyber attack.

For businesses, the consequences go far beyond data loss. A security incident can cause system downtime, encrypted data, production disruption, and prolonged recovery.

So, what is a cyber attack, what are the most common types, and where should businesses start when it comes to prevention?

Below are six common types of cyber attacks and key measures businesses can take to proactively reduce cybersecurity risks.

1. What Is a Cyber Attack?

A cyber attack is an attempt to gain unauthorized access to, steal data from, damage, or disrupt computer systems, networks, applications, or digital devices.

Attackers may target:

• Accounts and login credentials
• Business data
• Computers and endpoints
• Email, websites, and applications
• Servers and network infrastructure

A cyber attack does not always begin with a sophisticated technique. A single employee clicking on a phishing email can create an initial entry point into the organization.

That is why building an effective cybersecurity system involves more than protecting IT infrastructure. It also requires protecting people, devices, data, and the organization's ability to respond when an incident occurs.

2. Who Can Become a Target of Cyber Attacks?

Almost any individual or organization that owns valuable data or systems can become a target.

For businesses, attackers commonly target:

Data → Accounts → Systems → Financial Assets → Business Operations

This is particularly important for manufacturing companies, where IT systems are increasingly connected with engineering data, operational processes, and various devices.

As a result, a cybersecurity incident may go beyond data loss and lead to business or production disruption.

Businesses therefore need to consider four capabilities together: prevention, detection, response, and recovery.

3. Why Do Hackers Launch Cyber Attacks?

Cyber attacks can have many different objectives. Common motivations include:

• Data theft: stealing customer information, credentials, internal data, or intellectual property.
• Extortion: encrypting or taking control of data and demanding a ransom.
• Unauthorized access: compromising accounts or devices to enable further attacks.
• Disruption: making websites, servers, or systems unavailable.
• Espionage: secretly monitoring and collecting information over an extended period.

However, malicious attacks should be distinguished from authorized security testing and attack simulations. These activities are conducted with permission to proactively identify weaknesses before real attackers can exploit them.

4. 6 Common Types of Cyber Attacks

4.1. Malware and Ransomware – When Malicious Software Enters the System

Malware is a broad term covering malicious software such as viruses, worms, Trojans, spyware, and ransomware.

Malware can enter a system through:

• Email attachments
• Malicious websites or links
• Software from untrusted sources
• Compromised devices
• Unpatched vulnerabilities

Among these threats, ransomware is particularly concerning for businesses because it can encrypt data, disrupt systems, and be used for extortion.

The key question is therefore not only:

“Can the business prevent ransomware?”

But also:

“If ransomware gets through the defenses, how long will it take to recover?”

This is why businesses should assess their ransomware prevention and recovery readiness, including existing protection, backups, and the ability to restore systems after an incident.

4.2. Phishing – When Attackers Target People

An email that appears to come from a bank. A password reset request from “IT.” An attachment seemingly sent by a customer or business partner.

It could be phishing.

Phishing involves attackers impersonating a trusted person or organization to persuade victims to:

• Click a malicious link
• Open a malware-infected attachment
• Provide usernames and passwords
• Disclose sensitive information
• Perform an unintended action

What makes phishing dangerous is that attackers do not necessarily need to break through security technology if they can convince users to open the door for them.

In addition to cybersecurity awareness training, businesses can conduct phishing email simulations to evaluate how employees respond to realistic scenarios and identify groups or behaviors that may present higher risks.

4.3. SQL Injection – Targeting the Data Behind Applications

SQL Injection exploits weaknesses in how an application processes user input, allowing an attacker to send unintended SQL commands to a database.

If successful, attackers may be able to:

• Access data without authorization
• Modify or delete data
• Expose customer information
• Disrupt application operations

SQL Injection demonstrates how a weakness in an application can become a gateway to valuable data behind it. Businesses therefore need to consider not only endpoint protection but also vulnerabilities and security configurations across their IT environment.

4.4. DoS and DDoS – When Systems Become Overloaded

A DoS (Denial of Service) attack aims to prevent a system or service from serving legitimate users by overwhelming or exhausting its resources.

A DDoS (Distributed Denial of Service) attack has a similar objective, but the attack traffic comes from multiple distributed sources.

In simple terms:

DoS: one or a few sources → target
DDoS: multiple distributed sources → target

If successful, websites, servers, or online services can become severely degraded or completely unavailable, directly affecting users and business operations.

4.5. Zero-Day – When a Vulnerability Has Not Yet Been Patched

A zero-day vulnerability is a security flaw for which a patch is not yet available or which has not yet been addressed by the software vendor when attackers begin exploiting it.

Because there may be no immediate fix, businesses need multiple layers of defense, including:

• Regular system updates and patching
• Access control
• Endpoint protection
• Monitoring for unusual behavior
• Network segmentation
• Incident response planning

Beyond zero-day threats, proactively assessing vulnerabilities and security configurations can help businesses identify weaknesses already present in their IT environment and determine which issues should be addressed first.

4.6. Man-in-the-Middle – When Data Is Intercepted in Transit

A Man-in-the-Middle (MitM) attack occurs when an attacker positions themselves between two parties to monitor or interfere with the data being exchanged.

The risk can increase when users rely on:

• Unsecured Wi-Fi networks
• Connections without appropriate encryption
• Weak authentication mechanisms

If successful, attackers may capture login credentials or sensitive information that users believe they are sending directly to the intended recipient.

5. How Can Businesses Prevent Cyber Attacks?

No single security solution can prevent every cyber attack.

Rather than simply adding more tools, businesses should build multiple layers of defense around people, systems, devices, data, and recovery capabilities.

Assess User Awareness

Employees should be trained to recognize phishing, suspicious emails, and social engineering techniques.

More importantly, businesses can use phishing email simulations to test employee awareness in realistic scenarios rather than relying solely on theoretical training.

Proactively Identify System Weaknesses

Software should be kept up to date, security patches should be deployed, and insecure configurations should be identified early.

Regular vulnerability and security configuration assessments can help businesses understand what weaknesses exist, how serious they are, and which issues should be prioritized.

Protect Endpoints

Laptops, desktops, and other endpoints are often among the first points of contact in a cyber attack.

Endpoint Security solutions combining EPP and EDR capabilities can help businesses prevent threats, monitor endpoints, and detect suspicious behavior.

New System Vietnam provides Trend Micro Apex One to support enterprise endpoint protection requirements.

Prepare for Recovery

Having backups does not automatically mean a business can recover quickly from an incident.

Businesses need to evaluate the entire recovery chain:

Backup → Backup Protection → Recoverability → Recovery Time

For ransomware in particular, assessing prevention and recovery readiness can help identify gaps that could significantly extend downtime when a real incident occurs.

6. Is Your Business Really Ready for a Cyber Attack?

Instead of simply asking “Do we already have cybersecurity software?”, businesses should consider four more practical questions:

1. If a phishing email arrives today, will employees recognize it?

2. If a critical vulnerability exists in the system, will the business know about it?

3. If an endpoint is compromised, can the incident be detected early enough to respond?

4. If ransomware strikes tomorrow, how long will it take to restore operations?

If any of these questions does not have a clear answer, it may indicate a cybersecurity gap that should be assessed and prioritized.

Conclusion: Don't Wait for an Incident to Test Your Security

A cyber attack can begin with a single email, account, endpoint, or vulnerability. But the consequences can extend to data loss, system downtime, and disruption of business operations.

Cybersecurity therefore should not focus solely on trying to “avoid being attacked.” Businesses also need to understand:

Where are the weaknesses? → Can they be detected? → How effectively can they be prevented? → If an incident occurs, how quickly can operations recover?

New System Vietnam supports businesses in building security solutions aligned with their current environment, including phishing email simulations, system vulnerability assessments, ransomware prevention and recovery readiness assessments, and endpoint protection.

👉 Contact New System Vietnam to assess your current security environment and identify the cybersecurity gaps that should be prioritized.

Frequently Asked Questions About Cyber Attacks

1. What is a cyber attack?

A cyber attack is an attempt to gain unauthorized access to, steal data from, damage, or disrupt computer systems, networks, applications, or digital devices.

2. What are the most common types of cyber attacks?

Common cyber attacks include phishing, malware/ransomware, SQL Injection, DoS/DDoS, zero-day exploits, and Man-in-the-Middle attacks.

3. What is the difference between phishing and malware?

Phishing primarily uses impersonation and social engineering to persuade users to take an action. Malware is malicious software. In many cases, phishing is used as a method for delivering malware.

4. What is ransomware?

Ransomware is a type of malware commonly used to encrypt or take control of data, after which attackers demand a ransom from the victim.

5. Can businesses completely prevent cyber attacks?

No organization can eliminate every cybersecurity risk. Businesses should combine prevention, detection, response, and recovery to reduce both the likelihood and potential impact of an attack.