How Not to Get Hacked: An Overview of Cyber Attacks

How Not to Get Hacked: An Overview of Cyber Attacks

In today’s interconnected world, cybersecurity is no longer optional—it’s essential. Hackers use numerous methods to gain unauthorized access to information, systems, and networks. Understanding these methods is the first and most critical step in defending yourself, whether you are an ordinary user or a server administrator.

The Most Common Types of Cyber Attacks and Simple Countermeasures

Cyber attacks are diverse, but some are used continuously and inflict severe damage. Here, we introduce the most important ones and provide simple yet effective solutions for mitigation.

Phishing Attacks

Phishing is one of the most widespread social engineering attacks, relying on deceiving the victim into divulging sensitive information. In this method, attackers impersonate a legitimate and trusted entity (like a bank, a large company, or a colleague) to gain critical information such as usernames, passwords, or credit card details. This attack often occurs via emails, text messages, or fraudulent websites designed to misleadingly resemble the original ones, thereby encouraging the victim to enter their personal data.

Simple Prevention Solutions:

• Always carefully check the sender’s address and the website’s URL for any small inconsistencies.
• Never click on links sent unexpectedly; instead, manually type the intended website’s address directly into your browser.
• Use Two-Factor Authentication (2FA) for all your important accounts. This creates a powerful security layer that makes hacker access nearly impossible, even if your password is stolen.

SQL Injection Attacks

This attack specifically targets the server environment and websites that use SQL databases for storing information. In an SQL Injection attack, the attacker sends malicious SQL code through input fields (e.g., search forms, login forms, or comments) to the website’s database. If the system fails to properly sanitize and filter the user input, the injected code is executed, allowing the attacker to access, view, modify, or even completely delete sensitive data in the database.

Simple Prevention Solutions (For Server/Website Administrators):

• The most important security principle here is to never trust user input. All user input must be rigorously filtered and validated before being used in SQL queries.
• The most effective technical solution to prevent these attacks is to use Prepared Statements in your programming code, as this treats user input as data, not as an executable part of the SQL command.

Man-in-the-Middle Attacks (MITM)

MITM attacks occur when an attacker secretly places themselves between two communicating parties (e.g., a user and a website or server), intercepting and potentially altering all data exchanged between them. This attack can happen on insecure public networks (like café Wi-Fi) or by tricking devices into routing traffic toward the attacker’s machine. The main goal is to steal login credentials, session cookies, or other unencrypted data. This risk is significant for both Virtual Private Servers (VPS) and Dedicated Servers that offer services over HTTP.

Simple Prevention Solutions:

• To prevent MITM attacks, ensure you always use the HTTPS protocol. Server administrators must confirm that a valid SSL/TLS certificate is installed and that all traffic is forcibly redirected from HTTP to HTTPS.
• Additionally, avoid using public Wi-Fi networks without a password for sensitive tasks or ensure you are using a secure VPN to encrypt your traffic on these networks.

Denial of Service Attacks (DDoS/DoS)

A DoS (Denial of Service) attack occurs when an attacker overwhelms a target server with a massive volume of fake requests, consuming its resources (bandwidth, CPU, memory). This results in the server becoming unavailable to legitimate users. DDoS (Distributed Denial of Service) is the same attack, except it uses multiple distributed and infected sources (usually a network of devices called a botnet) to send requests, making detection and mitigation significantly harder. These attacks directly target the server environment and lead to service downtime.

Simple Prevention Solutions (For Server Administrators):

• The most crucial measure is to use DDoS protection services that filter incoming traffic and block malicious requests (such as Cloudflare services or other Web Application Firewalls – WAFs).
• Also, implementing Rate Limiting in the server firewall is essential. This restricts the number of requests a specific IP address can send within a given time frame, preventing the server from being overwhelmed.

Cross-Site Scripting Attacks (XSS)

This is one of the most common web vulnerabilities and is directly associated with web applications typically hosted on a server. In an XSS attack, the attacker injects malicious client-side code (usually JavaScript) into a legitimate website. When another user views the compromised page, their browser executes the malicious code, allowing the hacker to steal the user’s sensitive information like Session Cookies, modify data, or redirect the user to other pages.

Simple Prevention Solutions (For Server/Website Administrators):

• Use Output Encoding: Before displaying user input on a web page, you must Output Encode it so the browser reads it as plain text, not as executable code.
• Input Sanitization and Validation: All user inputs and URL parameters must be rigorously sanitized and validated to remove malicious HTML or JavaScript tags.
• Configure HTTP Security Headers: Using headers like Content-Security-Policy (CSP) can instruct the browser to only load resources (scripts) from trusted sources.

Password Attacks (Brute Force and Dictionary Attacks)

These attacks have a very specific goal: finding the correct password to access a user account, administrative panel, or server services like SSH or FTP. In a Brute Force attack, the attacker attempts to discover the password by trying every possible combination of characters. A Dictionary Attack starts with a list of common words and phrases that are highly likely to be used.

Simple Prevention Solutions:

• Strong and Unique Passwords: Always use long passwords (at least 12 characters) combining upper and lowercase letters, numbers, and symbols.
• Limit Login Attempts: In system or server settings, limit the number of unsuccessful login attempts (e.g., blocking the IP address for a short period after 5 failed tries). This is easily implemented on servers using tools like Fail2ban.
• Use 2FA or SSH Keys: Never rely solely on a password for sensitive administrative access to a Virtual oder Dedizierter Server.

Zero-Day Exploits

Zero-Day attacks occur when an attacker discovers a vulnerability in a software or operating system that the vendor or developer is not yet aware of or for which they have not released a patch. The developer has had zero days to fix the problem. These can be the most dangerous type of attacks because no known defense exists at the moment of the attack, and they can target both types of Server and applications.

Simple Prevention Solutions:

• Defense-in-Depth Strategy: Since a vulnerability cannot be predicted, you must have multiple layers of security. If one layer (e.g., the website software) is compromised, the other layers (e.g., the server firewall) should prevent the attacker from gaining full system access.
• System Segmentation: Place critical systems in separate segments of the network so that if one is infected, the others remain protected.
• Remove Unnecessary Software: Every service or piece of software installed on your server presents a potential vector for a Zero-Day vulnerability. Only install and keep active the services you absolutely need.

Security Differences in Virtual vs. Dedicated Server Environments

Server security is always the responsibility of the user or system administrator, but the type of server (virtual or dedicated) determines the extent and nature of your responsibilities, making the role slightly different in securing each.

In a Dedizierter Server, you, as the customer, have complete and absolute control over the physical hardware, operating system, and all installed software. Here, all security responsibility rests with you. This includes installing hardware or software firewalls, updating the operating system kernel, managing security patches, and constantly monitoring all server logs for intrusion detection. The big advantage is a potentially higher level of security, as there are no “neighbors” (other servers) that can compromise your system through shared infrastructure vulnerabilities.

Conversely, a Virtual Private Server (VPS) is an isolated, virtual segment of a larger physical server managed by a Hypervisor. With a VPS, security responsibility is shared: the service provider is responsible for the security of the physical hardware, network infrastructure, and the Hypervisor itself (underlying security). You are responsible for the security of the guest operating system, applications, and your own data. A key difference is that, in a VPS, mitigating large DDoS attacks is more dependent on the service provider’s anti-DDoS infrastructure, and your ability to change network settings at the hardware level is more limited.

Essential Critical Security Measures for the Server Environment

Whether you use a Virtual or a Dedicated Server, the following measures are necessary to prevent server compromise from various cyber attacks.

Access Management and User Segmentation

Whether on a Dedicated Server with full control or a VPS, the Principle of Least Privilege must be enforced. This means giving users and processes the minimum level of access required to perform their tasks.

• Use Non-Root Users: Never use the Wurzel (in Linux) or Administrator (in Windows) account for routine tasks. If an attacker gains access to a normal user account, the damage they can inflict will be significantly limited.
• Process Isolation: Run critical processes like the web server (e.g., Apache or Nginx) and database with users who have the least privilege. This prevents an attacker, if the web server is compromised, from gaining access to the entire file system.

Backup and Recovery

One of the most effective measures to minimize damage from attacks like Ransomware or malicious intrusions is having a strong and consistent backup strategy.

• Off-site Backup: Store backup copies not just on the same server but in a completely separate location (e.g., a secure cloud space or another separate server). This ensures that even if your entire primary physical or virtual server is compromised, your data will still be recoverable.
• Recovery Testing: A backup without testing is worthless. Periodically practice the data recovery process to ensure that the procedure works correctly during a crisis.

Configuration Management

Incorrect server configuration is one of the biggest sources of vulnerability.

• Disable and Remove Unnecessary Services: Deactivate or remove unnecessary services that are installed by default on the operating system
• Secure Remote Protocols: For both Dedicated and Virtual Servers, only use secure protocols like SSH (with cryptographic keys) and completely disable insecure legacy protocols like Telnet.

By adhering to these comprehensive and specialized points, whether you are managing a Dedicated Server with full security responsibility or a Virtual Server with shared responsibility, you can effectively reduce the risk of being hacked and maintain a secure online environment for yourself and your users.