The 10 Most Common Types of Cyber Attacks and Their Impact on Our Privacy

Ever since the release of one of the most potent and malicious computer viruses in August 2003, blaster, people started to wonder whether the biggest modern invention, the Internet, was safe.

Although the initial idea of the Internet was to facilitate the data transmission within smaller, usually scientific groups, it surprisingly became available to a broader audience – or better said, to billions of people worldwide.

Having such a number of people connected to the world wide web opened the door to cybercrime and hacking science, which keeps developing day by day, creating new types of cyber attacks.

The following post will provide you with a list of the 10 common cyber attacks and their impact on particular real-life situations, where they threatened to destroy the most prominent organizations, government, and military institutions.

What is a Cyber Attack?

Cyber-attacks or computer attacks are malicious and deliberate attempts usually created by an individual or an organization to breach the information systems, computer networks, or infrastructures of another individual or organization.

Such attacks use malicious code to modify computer code, data, or logic – those modifications cause severe consequences that can compromise your data, steal identity, or affect computer performance.

Attackers usually benefit from compromising someone’s network or system, which is why their attacks are mostly aimed at large enterprises, banks, and e-commerce websites where people leave their credit card information.

The Ultimate List of Common Cyber Attacks

Right after the first cyber attacks that hit the most prominent global companies, hackers started spreading their art of writing malicious codes.

Accordingly, the list of viruses we know today is just a small part of what the hacker’s mind can create, and we’ll try to provide as many examples as we can.

list of types of cyber attacks

1.      Malware Attacks

Malware attacks are among the most common types of malicious codes, and almost every company and user had an opportunity to face the damage caused by this virus at least once.

Malware consists of a code that affects the compromised computer system without the consent of a user. It usually spreads across a network, causes changes and damage, and persists in the infected system.

It’s mostly undetectable since it comes hidden in another file, and the antivirus program sometimes fails to identify it as malicious software. Its main goal is to disrupt, disable, and take control over your system as soon as it defines the technical flaws or vulnerabilities in your hardware and software.

Malware comes in many forms, among which the most common ones are:


Ransomware locks the infected system and blocks access to a user’s data, threatening to delete it until the ransom is paid. However, there is no guarantee that attackers will give you back the data even if you pay for the ransom.

This type of ransomware is known as Locker Ransomware, and it’s most common type is called Reveton. It started to appear at the end of 2012 in the form of legitimate, official-looking messages, locking the users’ system and saying that they had been involved in an illegal activity for which they had to pay the “fine.”

Another form of ransomware is Crypto Ransomware, which appeared in 2013, encrypting the users’ data with a different, randomly-generated symmetric key for each file. The attackers usually ask you to pay the ransom to get the decryption key and recover your files.

The most common types of Crypto-Ransomware are Crypto Wall, TorrentLocker, Bitcryptor, Locky, and WannaCry.

Drive-By Attack

Drive-by attacks are a fast way of installing malware to users’ computers without requiring them to do anything but enter the website.

Once attackers find insecure websites, they plant a malicious script into PHP or HTTP in one of their pages. As you enter the website, the infected file automatically downloads to your computer or mobile device, looking for outdated apps of all kinds.

As soon as it spots the weaknesses, the malware executes and takes control of the system. Such attacks usually happen when you use outdated software or browser, or due to implementing the antivirus that comes from untrusted sources and fails to identify the malware on the web.

Trojan Horses

Among all the malware types, Trojan Horse is the most known one. As its name says, it appears in the form of a harmless, routine software, persuading an individual to install it. Once they do, Trojan shows its power, usually by stealing financial information.

Trojan Horse can come in many forms – it’s usually hidden inside a file you downloaded from the untrusted website, and it can be a video game, an mp3 song, a PDF file, a media player, or anything else.

There are the 3 most usual Trojan Horse types:

  • Backdoor Trojan: It gives hackers malicious access to take remote control over the compromised computer. Such access allows them to send, receive, delete, and open files, as well as to display data and reboot the computer.
  • Trojan-Spy: As the name says, Trojan-Spy monitors the user’s computer activity, tracks the data, takes screenshots, or extracts a list of running applications.
  • Trojan-GameThief: This type of malware is targeted to online gamers, with a motive to steal their account information.

The complete list of Trojans is much longer, and it contains the malware types that can affect almost every system component and steal the most sensitive data of users and companies.


Worms are the quickest and the most persistent malicious programs that don’t need another file or app to copy itself.

That said, warm is a self-sustaining running program that replicates over a network using protocols. It relies on security failures found on the target computer, taking advantage of them to access the system.

Although worm usually causes some harm to the network, it doesn’t corrupt or modify the files on the computer. However, some malicious forms of the worm, such as so-called “payloads” are programmed to delete files, encrypt files, and steal data that contains confidential documents and passwords.

2.      Phishing Attacks

Phishing cyber-attack is created to steal sensitive user data such as credit card information and login credentials.

Attackers usually implement it by creating false and malicious websites or links, tricking the victim into entering and leaving their confidential data. Such links mostly come in the form of an email attachment, but they can also be hidden inside a text message. As soon as the victim opens the message or attachment, the malware executes and causes the breach.

The reason why many people get tricked into the phishing trap is the authenticity of the message. Namely, scammers usually modify the URLs of the reputable websites, making it difficult to notice the difference – for example, pyapal.com instead of paypal.com.

The breach caused by phishing can cause severe consequences, including data theft, stealing of funds, or unauthorized purchases.

Here is the list of the most frequent forms of phishing attacks:

Spear Phishing Attacks

Spear phishing attacks come in the form of an email aimed at a particular individual or organization requesting access to vital information.

Such emails seem to originate from someone within the recipient’s organization or someone that the target knows personally, which is why such attacks often finish their job successfully.

The most representative example of such an attack is the case of a Bangladesh Bank robbery, which took place in February 2016. Namely, the bank’s system was compromised by the hackers outside Bangladesh, which transferred about $81M to the Federal Reserve Bank of New York.

The investigation confirmed the presence of spear-phishing emails sent to bank employees, which gave hackers access to the bank’s network and allowed them to send messages via SWIFT (Society of Worldwide Interbank Financial Telecommunication).

Whale Phishing Attacks

Whale phishing attack or whaling is a type of cybercrime that’s focused on high-profile employees such as CEOs and CFOs.

Since “big fish” or “whales” inside the company have unlimited access to all kinds of sensitive data, hackers target their email servers, trying to get valuable information. Such attacks are not easily detected, mostly because they only sit and wait – at least at the beginning.

First, they monitor the CEO’s activity, studying their calendar for holidays, observing the inbox, mimicking the tone of their voice, paying attention to how they sign the emails and how they call their CFO.

Once they’ve got all the data, they send an email to CFO, making it look authentic and trustworthy, requesting the CFO to pay an invoice. It’s hard to notice anything suspicious since scammers pay attention to each detail, making the company lose a lot of money.

3.      SQL Injection

SQL Injection attack or SQLI attack is among the most common forms of cybercrime, and it’s targeted to any website that uses a SQL (Structured Query Language) driven with poor code.

Hackers can quickly check whether the website uses the SQL – if it does, they can inject the malicious code into the backend database and access information that was not intended to be exposed. Such information usually includes private customer details, user lists, and sensitive company data.

The SQL attack can be dangerous for the business, causing the deletion of entire tables, unauthorized viewing of the users’ list, and sometimes, a network attacker can gain access to the whole database. Businesses that suffered the SQL attack experienced the loss of customer trust since they were held responsible for exposing the addresses, credit card details, and phone numbers.

Executing the SQL attack is quite a smooth move, which is why companies should upgrade their security measures as soon as possible.

4.      Cross-Site Scripting (XSS) Attack

Cross-site scripting is another type of injection breach, where hacker injects malicious code to reputable websites. It usually happens when the external source (a user) is allowed to attach its own code to the application and take control over it.

Malicious code used for XSS attacks is mostly sent in the form of JavaScript, HTML, or Flash code, and it’s executed as soon as the victim clicks on it. XSS attacks are aimed at stealing users’ data, and hackers mostly get notified as soon as the malicious script gathers the victim’s personal information, credit card numbers, and sensitive credentials.

XSS vulnerabilities inside the web apps are easy to spot, they are easily exploited, and they have a high impact on business performance, just like the SQL injection.

cyber attack definition

5.      Distributed Denial of Service (DDoS) Attack

DDoS attacks are focused on shutting down the entire network or service, making it inaccessible to its intended users.

They are executed by overwhelming the target website with excessive amounts of traffic or information that cause a site crash. When something like that happens, neither employees, users, account holders, nor members of service can access it.

Hackers always perform DDoS attacks on high-profile organizations, such as trade companies, government, media companies, e-commerce, and banking sites. Even though such attacks don’t cause identity or money theft, they can cost a victim a lot of money and time.

The most famous DDoS attack happened in 2000, and it was aimed at Yahoo, FIFA, Amazon, CNN, and eBay. It crashed the most reputable websites at that time, and the culprit even ended up in jail.

6.      Eavesdropping Attacks

Eavesdropping attack is among the most common network security attacks conducted by hackers who’re trying to steal information that computers, smartphones, or digital devices, in general, send or receive.

The hackers search for a weakened connection between the client and the server, which allows them to receive network transmission. By installing network monitors, such as sniffers on a server or computer, attackers can perform eavesdropping and collect all data being transmitted.

Any device that sends or receives data over the Internet is a potential vulnerability point, especially if it’s connected to the untrusted networks, such as a public Wi-Fi. Another factor that can facilitate the hackers’ job is software run on device you use – if it’s outdated, you are the perfect target for such attacks.

Eavesdropping is hard to detect since it doesn’t cause any abnormal data transmissions.

7.      Man-in-the-Middle (MITM) Attacks

Man-in-the-Middle (MITM) attack, like the Eavesdropping breach, allows the attacker to get in the middle of a conversation between two entities. That said, an attacker can listen to the conversation by intercepting the public key message transmission and retransmitting it while interchanging the requested key with its own.

These attacks are also almost undetectable, and the communication between two parties will seem as usual, even if the intruder is taking control over it. Again, the MITM can be easily performed when parties are connected to a free, public Wi-Fi access point, which is a goldmine for cybercriminals.

8.      Zero-Day Exploit

Zero-day attacks investigate vulnerabilities in software or hardware, and they strike before a developer has the chance to create a patch that fixes the existing flaw.

Accordingly, they leave no opportunity to be detected right away, but as soon as the patch is written and used, the exploit is no longer named a “zero-day.” However, a developer may need even months and years to detect the flaw that opened the door to attack.

types of hacking attacks

9.      Birthday Attack

A birthday attack is a type of cryptographic attack, based upon the mathematical birthday paradox, which lies on the fact that in a room with 23 people or more, the chances are higher than 50% that two people share the same birthday.

That said, a birthday attack can be used in communication abusage between two or more parties. It depends on a fixed degree of permutations and the higher likelihood of collisions found between random attempts of attack, as described in probability theory.

These attacks are aimed against hash algorithms used to verify the integrity of a message, software, or digital signature.

10.       Password Attacks

Passwords are the common mechanism used to authenticate users to an information system, which is why obtaining them is one of the most effective attack approaches.

Apart from “traditional” ways of obtaining passwords, such as looking around the person’s desk or “sniffing” the network connection to get unencrypted passwords, there are many other hacking techniques to steal passwords and gaining access to someone’s vital data.

Hence, the most common password attacks are:

  • Brute-force Attacks: Brute-force attack is an attempt to crack someone’s password or find the key used to encrypt a message by trying different passwords and hoping that one of them works. Although it’s old and doesn’t seem possible, this method has shown some good practices so far.
  • Dictionary attacks: This attack uses the dictionary of common passwords to gain access to an individual’s computer and network. For instance, they copy an encrypted file that contains all the passwords, apply the same encryption to a dictionary, and compare the results.

Verdict: Cybercrime Is the Threat That Never Ceases

The advent of the Internet has changed the norms and concepts of everyday life of all people around the globe. The power of the cybercrime grows together with the development of the Internet and being aware of its consequences makes us think about the cybersecurity measures we should take in order to stay protected.

Identity and money thefts, computer frauds, and deleting vital accounts are just a small piece of the much broader range of consequences brought by the cybercrime, which is why we must use the Internet carefully, paying attention to every detail.

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