Cyberattacks represent one of the greatest threats to modern organizations, regardless of their size or industry. In the era of digital transformation, as companies move more and more processes to digital environments, understanding the nature of cyberattacks and methods of defense becomes crucial for business survival and continuity.
What is a cyberattack?
A cyberattack is a deliberate, unauthorized action targeting computer systems, networks, or electronic devices, aimed at stealing data, disrupting system operations, extorting ransom, or causing financial and reputational damage. Cyberattacks can be carried out by individual hackers, organized criminal groups, or even state-sponsored cyber units.
The scale of the problem is enormous. According to the IBM Cost of a Data Breach 2025 report, the average global cost of a data breach was $4.44 million. The European Union Agency for Cybersecurity (ENISA) estimates that a ransomware attack occurs somewhere in the world every 11 seconds.
It is no longer a question of “if” a company will be attacked, but “when.” The vast majority of organizations have experienced more than one data security breach. Cyberattacks affect all sectors — from finance and healthcare, through manufacturing and energy, to public administration and education.
10 most common types of cyberattacks
1. Phishing
Phishing is the most common form of cyberattack, involving impersonation of trusted individuals or institutions to extract login credentials, financial information, or install malicious software. Phishing accounts for a large share of reported security incidents in many countries. Attacks take the form of fake emails from banks, courier companies, tax authorities, or e-commerce platforms. Variants include spear phishing (targeted at specific individuals), whaling (targeting senior management), and smishing (phishing via SMS).
Example: In 2024, a mass phishing campaign impersonating a major courier service affected thousands of users — fake SMS messages about the need to pay for a package redirected victims to sites that stole payment card details.
2. Ransomware
Ransomware is malicious software that encrypts the victim’s data and demands a ransom for its recovery. Modern variants use double extortion — in addition to encrypting, they steal data and threaten to publish it. Groups such as LockBit, BlackCat (ALPHV), and Cl0p run professional operations with Ransomware-as-a-Service models.
Example: The ransomware attack on Garmin in 2020 paralyzed services for millions of users for several days. The ransom reportedly amounted to $10 million. In 2021, CD Projekt RED fell victim — their game source code was stolen and sold at auction on the darknet.
3. DDoS attacks (Distributed Denial of Service)
DDoS attacks involve flooding a server or network with massive amounts of traffic from thousands of compromised devices (a botnet), leading to service unavailability. Modern DDoS attacks achieve volumes exceeding 1 Tbps. These attacks are sometimes used as a smokescreen for other, more advanced operations.
Example: A series of DDoS attacks on government institutions and banks in 2023, carried out by pro-Russian hacktivist groups, temporarily took down the websites of several ministries and online banking systems.
4. Man-in-the-Middle (MitM) attacks
In a MitM attack, an intruder intercepts communication between two parties, eavesdropping on or modifying transmitted data without the participants’ knowledge. These attacks are particularly dangerous on unsecured Wi-Fi networks, where the attacker can intercept login credentials, banking sessions, or confidential correspondence.
Example: Attacks on public hotspots in shopping centers and airports, where criminals create fake access points with names deceptively similar to official networks, intercepting all user traffic.
5. SQL Injection
SQL Injection is an attack on web applications that involves injecting malicious SQL code into form fields or URL parameters, allowing the attacker to read, modify, or delete data from the database. Despite being a well-known attack vector, it still features in the OWASP Top 10 as one of the most common threats.
Example: In 2015, an SQL Injection attack on TalkTalk servers led to a leak of 157,000 customer records, a fine of £400,000, and losses reaching £60 million.
6. Cross-Site Scripting (XSS)
XSS is an attack in which the attacker injects a malicious script into a website displayed to other users. The script executes in the victim’s browser, enabling theft of session cookies, form data interception, or redirection to fake sites. Types include reflected XSS, stored XSS, and DOM-based XSS.
Example: An XSS vulnerability in eBay allowed attackers to inject malicious product listings that could steal login credentials from users browsing the offers.
7. Zero-Day attacks
Zero-day attacks exploit previously unknown software vulnerabilities for which the vendor has not yet released a patch. They are exceptionally dangerous because traditional security systems do not recognize the new attack vector. Zero-day exploits are extremely valuable on the black market — their prices reach millions of dollars.
Example: The Log4Shell vulnerability (CVE-2021-44228) in the Log4j library affected hundreds of millions of devices worldwide. Due to the ubiquity of Log4j in Java applications, this attack had an enormous scale and required immediate response from security teams.
8. Advanced Persistent Threats (APT)
APTs are long-term, highly sophisticated attack campaigns typically conducted by state-sponsored groups. The goal is to quietly maintain access to the victim’s infrastructure for months or years, collecting intelligence and strategic information. APT groups employ sophisticated techniques to avoid detection.
Example: The APT28 group (Fancy Bear), linked to Russian GRU, has repeatedly attacked government and military institutions. In 2023, CERT agencies warned of a campaign targeting public administration, exploiting vulnerabilities in popular office software.
9. Supply chain attacks
A supply chain attack involves compromising a trusted software or service vendor to reach their customers. The attacker infects an update, library, or component delivered by a trusted partner, enabling mass distribution of malicious code.
Example: The SolarWinds attack in 2020 — hackers injected a backdoor into an update of the Orion platform, used by tens of thousands of organizations, including US government agencies. They remained undetected for 9 months, having access to sensitive systems.
10. Social engineering
Social engineering is a broad term encompassing psychological manipulation techniques aimed at persuading victims to reveal confidential information or perform specific actions. It includes pretexting (creating a false scenario), baiting (planting infected media), tailgating (physically following an authorized employee), and quid pro quo.
Example: A Twitter employee fell victim to a phone attack — a person impersonating the IT department convinced them to reset access credentials, enabling the takeover of accounts belonging to prominent individuals (Elon Musk, Barack Obama, Apple) in July 2020.
Anatomy of a cyberattack — Cyber Kill Chain stages
Understanding the course of a cyberattack is crucial for effective defense. The Cyber Kill Chain model developed by Lockheed Martin describes seven stages of a typical cyberattack:
1. Reconnaissance
The attacker gathers information about the target — organizational structure, technologies used, employee email addresses, open ports, publicly available data. They use OSINT (Open Source Intelligence), port scanners, social media, and search engines.
2. Weaponization
Based on the gathered information, the attacker prepares attack tools — a malicious document, an infected link, an exploit for an identified vulnerability. They create a payload tailored to the victim’s infrastructure.
3. Delivery
The malicious payload is delivered to the victim — most commonly through email phishing, an infected website, malicious attachments, USB, or compromised software.
4. Exploitation
The payload exploits a security vulnerability — this could be an unpatched vulnerability, a configuration error, a weak password, or a zero-day vulnerability. At this point, the attacker gains initial access to the system.
5. Installation
The attacker installs persistent access — a backdoor, RAT (Remote Access Trojan), rootkit, or web shell. The goal is to maintain access even after system restarts or password changes.
6. Command & Control
The infected system establishes communication with the attacker’s C2 server, enabling remote control, downloading additional tools, and data extraction. Communication is masked within HTTPS, DNS traffic, or on cloud platforms.
7. Actions on objectives
The final stage — the attacker achieves their actual goal: data theft, ransomware encryption, system sabotage, espionage, or preparing infrastructure for further attacks. This stage can last minutes (ransomware) or months (APT).
Effective defense relies on breaking the chain at the earliest possible stage. The sooner we detect an attack, the less damage the organization suffers.
The cost of cyberattacks
The financial consequences of a cyberattack extend far beyond direct losses. The following breakdown presents cost categories:
| Cost category | Description | Estimated range |
|---|---|---|
| Direct costs | Ransom, data recovery, system repair | Significant, even for SMEs |
| Operational downtime | Revenue loss from service unavailability | Significant for each day of downtime |
| Regulatory fines | GDPR (up to 4% of turnover), NIS2 | Up to millions of USD |
| Legal costs | Legal support, customer notifications | Significant |
| Reputation loss | Customer churn, trust erosion | Difficult to estimate |
| Insurance increases | Higher cyber insurance premiums | Significant annual increase |
According to the IBM Cost of a Data Breach Report 2025, companies need an average of 241 days to identify and contain a security breach. Each additional day generates further costs. Organizations with an incident response plan and a SOC team incur significantly lower costs per incident compared to companies without these safeguards.
How to protect your company from cyberattacks
Effective defense requires a layered approach (defense-in-depth), encompassing technology, people, and processes. No single solution will provide complete protection.
Technology layer
Next-Generation Firewall (NGFW) — a fundamental element of perimeter protection. Modern firewalls provide application-level traffic inspection, IPS (Intrusion Prevention System), URL filtering, and sandboxing. Proper firewall deployment is the foundation of security architecture.
EDR/XDR on endpoints — Managed EDR/XDR solutions monitor activity on workstations and servers, detecting suspicious behavior, blocking malware, and enabling rapid incident response.
SIEM and 24/7 monitoring — a Security Information and Event Management system collects and correlates logs from across the infrastructure, detecting anomalies and potential attacks. A professional SOC (Security Operations Center) provides round-the-clock security oversight.
MFA (Multi-Factor Authentication) — multi-factor authentication drastically reduces the risk of account takeover. MFA blocks the vast majority of automated attacks on accounts.
Network segmentation — dividing the network into isolated segments limits an attacker’s lateral movement. Even if one segment is compromised, the rest of the infrastructure remains protected.
Human layer
Cybersecurity training — regular employee training is the most effective investment in security. Employees should be able to recognize phishing, use strong passwords, and respond to suspicious situations. Simulated phishing attacks allow measuring the effectiveness of the program.
Security culture — building awareness that cybersecurity is everyone’s responsibility, not just the IT department’s. Clear policies, rapid incident reporting, and a no-blame culture encourage a proactive approach.
Process layer
Regular updates and patching — unpatched vulnerabilities are one of the main attack vectors. Automating the patching process and prioritizing critical fixes minimizes the window of vulnerability.
3-2-1 Backup — three copies of data, on two different media, one copy offline (off-network). Regular testing of backup recovery is just as important as creating backups.
Penetration testing — regular security audits and penetration tests reveal vulnerabilities before attackers do. The recommended minimum is one penetration test per year and an audit after every significant infrastructure change.
Incident response plan — a documented incident response plan with clear role assignments, escalation procedures, and contact lists. The plan should be regularly practiced in the form of tabletop exercises.
What to do after a cyberattack
When a security incident occurs, every minute counts. A proper response can determine the scale of losses.
Immediate actions (first hours)
- Isolate infected systems — disconnect compromised devices from the network, but DO NOT shut them down (RAM contains valuable forensic evidence).
- Notify your IT/SOC team — activate the incident response team. If the company does not have its own team, contact a professional firm offering incident response.
- Secure evidence — preserve system logs, memory dumps, network artifacts. Document all actions with precise timestamps.
- DO NOT pay the ransom — paying does not guarantee data recovery, funds criminal activity, and makes the company a repeat target.
Containment and recovery phase (days)
- Analyze the scope of the breach — determine which systems, data, and accounts have been compromised. Identify the attack vector and close the vulnerability.
- Eradicate the threat — remove malware, backdoors, and compromised accounts. Reset passwords for all potentially affected users.
- Restore from backups — recover systems from trusted, clean backups. Verify the integrity of restored data.
Legal obligations
Under the GDPR, a company must report a personal data breach to the relevant data protection authority within 72 hours of its detection. If the breach poses a high risk to the rights of the individuals whose data is concerned, those individuals must also be notified.
The NIS2 Directive imposes additional obligations on essential and important entities — including the obligation to report serious incidents to the national CSIRT within 24 hours. Non-compliance with NIS2 requirements carries fines of up to EUR 10 million or 2% of annual turnover.
Lessons learned phase
- Post-incident review — conduct a detailed incident analysis (lessons learned). What worked, what failed, what changes need to be implemented.
- Update security measures — implement fixes resulting from the incident analysis. Update policies, procedures, and security tools.
- Communication — transparent communication with customers, partners, and regulators builds trust. Concealing incidents damages reputation and exposes the company to fines.
Frequently asked questions
What are the most common types of cyberattacks?
The most common are phishing (the vast majority of attacks start with phishing), ransomware (encrypting data for ransom), DDoS attacks (server overload), supply chain attacks, and zero-day exploits. Phishing is particularly prevalent because it exploits the weakest link — the human factor. Ransomware, on the other hand, is the most financially devastating, forcing downtime and potential data loss.
How much does a cyberattack cost a company?
According to the IBM Cost of a Data Breach Report 2025, the average global cost of a data breach is $4.44 million. For SMEs, the average incident cost ranges from $50,000 to $125,000, including downtime, data loss, regulatory fines, and reputation rebuilding. Indirect costs — customer churn, increased insurance premiums, brand value decline — often far exceed direct costs and can burden a company for years.
How can you tell if your company has been hit by a cyberattack?
Warning signs include: unexpected system slowdowns, unknown processes in the task manager, antivirus or EDR alerts, unauthorized account logins, modified or encrypted files, ransom demands on screen, or unusual network traffic detected by SIEM/SOC. Early detection is crucial — the sooner you detect an attack, the less damage the organization suffers.
Are small businesses also targeted by cyberattacks?
Yes — small and medium businesses are a frequent target of cyberattacks. SMEs are attractive because they have weaker security than corporations but still hold valuable customer data, financial data, and intellectual property. A serious incident can threaten the very survival of an SME. For SMEs, the SOC as a Service model is particularly valuable, providing professional monitoring without the need to build an in-house team.
What should you do in the first minutes after a cyberattack?
Isolate infected systems from the network (don’t shut them down — preserve RAM contents!), notify your IT/SOC team, don’t pay the ransom, secure logs and evidence, and activate your incident response plan. Then report the incident to your national CERT and, in case of a personal data breach, to the relevant data protection authority within 72 hours. If the company does not have its own response team, it is critical to quickly engage a professional incident response team.
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