What is a cyber attack?

Cyber attacks are unwelcome attempts to steal, expose, alter, disable or destroy information through unauthorized access to computer systems.

Why cyber attacks happen

In addition to cybercrime, cyber attacks can also be associated with cyber warfare or cyberterrorism, like hacktivists. Motivations can vary, in other words. And in these motivations, there are three main categories: criminal, political and personal.

Criminally motivated attackers seek financial gain through money theft, data theft or business disruption. Likewise, the personally motivated, such as disgruntled current or former employees, will take money, data or a mere chance to disrupt a company's system. However, they primarily seek retribution. Socio-political motivated attackers seek attention for their causes. As a result, they make their attacks known to the public—also known as hacktivism.

Other cyber attack motivations include espionage, spying—to gain an unfair advantage over competitors—and intellectual challenge.

Who is behind cyber attacks?

Criminal organizations, state actors and private persons can launch cyber attacks against enterprises. One way to classify cyber attack risks is by outsider versus insider threats.

Outsider threats

External cyber threats include:

  • Organized criminals or criminal groups
  • Professional hackers, like state-sponsored actors
  • Amateur hackers, like hacktivists

Insider threats

Insider threats are users who have authorized and legitimate access to a company's assets and abuse them either deliberately or accidentally. They include:

  • Employees careless of security policies and procedures
  • Disgruntled current or former employees
  • Business partners, clients, contractors or suppliers with system access

What do cyber attackers target?

Cyberattacks happen because organizations, state actors or private persons want one or many things, like:

  • Business financial data
  • Clients lists
  • Customer financial data
  • Customer databases, including personally identifiable information (PII)
  • Email addresses and login credentials
  • Intellectual property, like trade secrets or product designs
  • IT infrastructure access
  • IT services, to accept financial payments
  • Sensitive personal data
  • US government departments and government agencies

What are common types of cyber attacks?

In the current, connected digital landscape, cybercriminals use sophisticated tools to launch cyber attacks against enterprises. Their attack targets include personal computers, computer networks, IT infrastructure and IT systems. And some common types of cyber attacks are:

Backdoor Trojan

A backdoor Trojan creates a backdoor vulnerability in the victim's system, allowing the attacker to gain remote, and almost total, control. Frequently used to link up a group of victims' computers into a botnet or zombie network, attackers can use the Trojan for other cybercrimes.

Cross-site scripting (XSS) attack

XSS attacks insert malicious code into a legitimate website or application script to get a user's information, often using third-party web resources. Attackers frequently use JavaScript for XSS attacks, but Microsoft VCScript, ActiveX and Adobe Flash can be used, too.

Denial-of-service (DoS)

DoS and Distributed denial-of-service (DDoS) attacks flood a system's resources, overwhelming them and preventing responses to service requests, which reduces the system's ability to perform. Often, this attack is a setup for another attack.

DNS tunneling

Cybercriminals use DNS tunneling, a transactional protocol, to exchange application data, like extract data silently or establish a communication channel with an unknown server, such as a command and control (C&C) exchange.


Malware is malicious software that can render infected systems inoperable. Most malware variants destroy data by deleting or wiping files critical to the operating system's ability to run.


Phishing scams attempt to steal users' credentials or sensitive data like credit card numbers. In this case, scammers send users emails or text messages designed to look as though they're coming from a legitimate source, using fake hyperlinks.


Ransomware is sophisticated malware that takes advantage of system weaknesses, using strong encryption to hold data or system functionality hostage. Cybercriminals use ransomware to demand payment in exchange for releasing the system. A recent development with ransomware is the add-on of extortion tactics.

SQL injection

Structured Query Language (SQL) injection attacks embed malicious code in vulnerable applications, yielding backend database query results and performing commands or similar actions that the user didn't request.

Zero-day exploit

Zero-day exploit attacks take advantage of unknown hardware and software weaknesses. These vulnerabilities can exist for days, months or years before developers learn about the flaws.

What can cyber attacks do?

If successful, cyber attacks can damage enterprises. They can cause valuable downtime, data loss or manipulation, and money loss through ransoms. Further, downtime can lead to major service interruptions and financial losses. For example:

  • DoS, DDoS and malware attacks can cause system or server crashes.
  • DNS tunneling and SQL injection attacks can alter, delete, insert or steal data into a system.
  • Phishing and zero-day exploit attacks allow attackers entry into a system to cause damage or steal valuable information.
  • Ransomware attacks can disable a system until the company pays the attacker a ransom.

As an illustration, DarkSide, a ransomware gang, attacked Colonial Pipeline, a large US refined products pipeline system, on April 29, 2021. Through a virtual private network (VPN) and a compromised password (link resides outside of ibm.com), this pipeline cyber attack gained entry into the company's networks and disrupted pipeline operations. In effect, DarkSide shut down the pipeline that carries 45% of the gas, diesel and jet fuel supplied to the US east coast. They soon followed their shutdown with a ransom note, demanding almost USD 5 million in Bitcoin cryptocurrency, which Colonial Pipeline's CEO paid (link resides outside of ibm.com).

After all, Colonial Pipeline hired a third-party cybersecurity firm and informed federal agencies and US law enforcement. USD 2.3 million of the ransom paid was recovered.

How cyber attacks can be reduced

Organizations can reduce cyber attacks with an effective cybersecurity system. Cybersecurity is the practice of protecting critical systems and sensitive information from digital attacks, involving technology, people and processes. An effective cybersecurity system prevents, detects and reports cyber attacks using key cybersecurity technologies and best practices, including:

  • Identity and access management (IAM)
  • A comprehensive data security platform
  • Security information and event management (SIEM)
  • Offensive and defensive security services and threat intelligence

Prevent cyber attacks

A threat management strategy identifies and protects an organization's most important assets and resources, including physical security controls for developing and implementing appropriate safeguards and protecting critical infrastructure.

Detect cyber attacks

The threat management system provides measures that alert an organization to cyber attacks through continuous security monitoring and early detection processes.

Report cyber attacks

This process involves ensuring an appropriate response to cyber attacks and other cybersecurity events. Categories include response planning, communications, analysis, mitigation and improvements.

Why is cybersecurity important?

Cybercrime can disrupt and damage enterprise business. In 2021, for example, the average cost of a data breach was USD 4.24 million globally and USD 9.05 million in the United States. These costs include discovering and responding to the violation, the cost of downtime and lost revenue, and the long-term reputational damage to a business and its brand. And in the case of compromised PII, it can lead to a loss of customer trust, regulatory fines, and even legal action.

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