Cyberattacks can target individuals, businesses, devices, applications, and networks. Attackers may try to steal information, gain access to accounts, disrupt services, install malicious software, or demand money.
Understanding the most common types of cyberattacks can help you recognize potential threats and take steps to protect your devices and information.
What are the most common types of cyberattacks?
Some of the most common cyberattacks include:
- Malware
- Phishing
- Ransomware
- Credential attacks
- Denial-of-service attacks
- Man-in-the-middle attacks
- Injection attacks
These attacks can overlap. For example, a phishing message may be used to deliver malware or steal a password, while stolen credentials may later be used to access a company's network.
1. Malware
Malware is short for malicious software. It is designed to disrupt systems, damage devices, steal information, or provide unauthorized access.
Common types of malware include:
- Viruses: Malicious programs that can spread by attaching themselves to other files or programs.
- Worms: Malware that can spread across systems and networks without requiring the same type of user interaction as a traditional virus.
- Trojans: Malicious software disguised as a legitimate file or application.
- Spyware: Software designed to secretly monitor activity or collect information.
- Ransomware: Malware that can encrypt or otherwise make data inaccessible while attackers demand payment.
- Adware: Software that displays unwanted advertisements and, in some cases, may also collect information or introduce additional security risks.
Malware can arrive through malicious downloads, compromised websites, email attachments, phishing messages, or exploited software vulnerabilities.
2. Phishing
Phishing is a social engineering attack that uses deceptive messages to trick people into taking an unsafe action.
A phishing message may ask you to:
- Click a link
- Open an attachment
- Enter your username and password
- Provide financial information
- Transfer money
- Download software
- Share a security code
Phishing does not only happen through email. Attackers can also use text messages, phone calls, social media, messaging apps, and other communication methods.
Some phishing attacks are highly targeted. Spear phishing is directed at a specific person or organization and may use personal or business information to make the message appear legitimate.
AI can also make phishing messages more convincing, which makes it especially important to slow down and verify unexpected requests before taking action.
3. Ransomware
Ransomware is malware that can prevent access to data or systems and demand payment from the victim.
In many ransomware attacks, attackers encrypt files so the victim cannot access them. Modern ransomware attacks may also involve stealing data and threatening to release it if a ransom is not paid.
Ransomware can affect organizations of any size. It can arrive through phishing, malicious files, compromised accounts, or exploited vulnerabilities.
The best defense is preparation. Keeping software updated, protecting accounts, maintaining reliable backups, and having a response plan can help reduce the impact of a ransomware attack. NIST's current ransomware guidance emphasizes preparation, protection, detection, response, and recovery.
4. Credential attacks
Credential attacks attempt to obtain or use usernames, passwords, authentication codes, or other account credentials.
Common examples include:
- Brute-force attacks: Repeatedly trying different passwords until one works.
- Password spraying: Trying a small number of commonly used passwords against many accounts.
- Credential stuffing: Using stolen usernames and passwords from one service to attempt access to other accounts.
- Credential phishing: Tricking someone into voluntarily entering their credentials into a fraudulent website or form.
Using unique passwords and multi-factor authentication (MFA) can help reduce the risk of account compromise. Phishing-resistant authentication provides an even stronger defense against some types of credential theft.
5. Denial-of-service attacks
A denial-of-service (DoS) attack attempts to make a website, application, server, or network unavailable by overwhelming its resources.
A distributed denial-of-service (DDoS) attack uses multiple systems to generate traffic or requests against a target.
The result can include:
- Slow website or application performance
- Connection failures
- Service outages
- Legitimate users being unable to access a resource
DDoS attacks primarily target availability rather than directly stealing information.
6. Man-in-the-middle attacks
A man-in-the-middle (MITM) attack occurs when an attacker intercepts or interferes with communication between two parties.
The goal may be to observe information, steal credentials, modify communications, or redirect a user.
Using encrypted connections, keeping devices and software updated, and avoiding untrusted networks can help reduce the risk. HTTPS and other secure communication protocols are important protections against unauthorized interception.
7. Injection attacks
Injection attacks occur when an attacker sends malicious input to an application in a way that causes the application to interpret that input as a command or code.
One well-known example is SQL injection.
SQL injection targets applications that interact with databases. If an application does not properly validate and handle user input, an attacker may be able to manipulate database queries and access or modify information they should not be able to reach.
Injection attacks are primarily a concern for application developers and organizations operating web applications. Secure development practices, input validation, parameterized queries, and regular security testing can help reduce the risk.
What do cybercriminals want?
Attackers have different goals depending on the type of attack and their motivation.
They may try to:
- Steal personal information
- Obtain usernames and passwords
- Access financial accounts
- Steal business or customer data
- Install malware
- Encrypt data and demand a ransom
- Disrupt websites or services
- Gain unauthorized access to networks
- Sell stolen information
- Use compromised devices for additional attacks
Some attacks are financially motivated, while others may be intended to disrupt operations, gather information, or support broader political or criminal objectives.
Who is at risk of a cyberattack?
Anyone who uses connected technology can be targeted by a cyberattack.
Individuals can be targeted through phishing, malware, account attacks, and scams. Businesses can face these threats as well as attacks targeting their networks, applications, employees, and data.
Being targeted does not necessarily mean you have done something wrong. Attackers often send large numbers of malicious messages or attempt automated attacks against many accounts and systems.
How can I protect myself from cyberattacks?
No single security measure can prevent every cyberattack. Instead, focus on several basic security practices.
For individuals
- Keep your software updated. Install security updates for your operating system, applications, browsers, and devices.
- Use unique passwords. Avoid reusing the same password across multiple accounts.
- Use multi-factor authentication. Enable MFA whenever it is available, especially for important accounts.
- Be cautious with unexpected messages. Don't click links or open attachments simply because a message appears urgent.
- Verify unusual requests. If someone asks you to transfer money, share sensitive information, or provide a security code, verify the request through a trusted method.
- Use security software. Keep built-in security protections and antivirus capabilities enabled and up to date.
- Back up important information. Maintain backups of important files so you have another way to recover from data loss or ransomware.
NIST recommends practices such as MFA, security software, software updates, and employee awareness as part of protection against common threats such as phishing and ransomware.
For businesses
Businesses should take a layered approach to cybersecurity.
Important measures include:
- Establishing an incident response plan
- Keeping systems and applications patched
- Using access controls and least-privilege permissions
- Requiring MFA for important accounts
- Training employees to recognize phishing and other social engineering
- Protecting and testing backups
- Monitoring networks and systems for suspicious activity
- Using firewalls and other appropriate security controls
- Regularly assessing vulnerabilities
- Planning for ransomware and other disruptive incidents
NIST's current cybersecurity guidance emphasizes preparing for incidents and having the ability to detect, respond to, and recover from attacks, rather than relying on a single security product.
Cyberattack FAQs
What is the most common type of cyberattack?
There is no single answer that applies to every person or organization. Phishing and other forms of social engineering are among the most common ways attackers try to trick people into giving up information or taking an unsafe action. Malware, credential attacks, ransomware, and other threats can follow from those initial compromises.
What is the most dangerous type of cyberattack?
The potential impact depends on the target and the attack. Ransomware can be particularly disruptive because it can prevent organizations from accessing critical data and systems, while attacks that steal credentials or sensitive information can lead to financial loss, fraud, or additional compromises.
Can antivirus software prevent cyberattacks?
Security software can help detect and block some malware and other threats, but it cannot prevent every type of cyberattack. Phishing, stolen credentials, social engineering, and other attacks may bypass antivirus protection. A layered security approach is more effective.
Can individuals be victims of cyberattacks?
Yes. Individuals can be targeted through phishing, malware, credential theft, scams, ransomware, and other attacks.
How can businesses prepare for a cyberattack?
Businesses should identify important systems and data, protect them with appropriate security controls, monitor for suspicious activity, train employees, maintain reliable backups, and create and test an incident response plan.
The bottom line
Cyberattacks come in many forms, and attackers continually adapt their methods. Malware, phishing, ransomware, credential attacks, DDoS attacks, man-in-the-middle attacks, and injection attacks are some of the threats individuals and businesses should understand.
The best defense is not one security tool. Keep your devices and software updated, protect your accounts with strong authentication, be cautious with unexpected messages, back up important data, and have a plan for responding to a security incident.
