Common Network Attacks: Top 5 Threats Explained

HISILA BHANDARI

Sat, 24 May 2025

In the digital era, network security is the bedrock of safe communication, commerce, and collaboration. As businesses, governments, and individuals increasingly rely on interconnected systems, the risk and complexity of cyber threats have grown exponentially. Among countless forms of cyberattacks, certain types have become especially prevalent, continually evolving to exploit new vulnerabilities. This blog post explores the ten most common network attacks in detail, explains how they work, and provides actionable strategies to prevent them.

1. Denial-of-Service (DoS) and Distributed Denial-of-Service (DDoS) Attacks

Denial-of-Service (DoS) attacks are among the oldest and most disruptive forms of cyberattacks. Their primary goal is to render a network, server, or service unavailable to legitimate users by overwhelming it with superfluous requests. While a single DoS attack may originate from one source, its more dangerous cousin—the Distributed Denial-of-Service (DDoS) attack—employs multiple systems (often a botnet) to increase the scale and difficulty of mitigation. The most common targets of DDoS attacks include financial institutions, e-commerce platforms, and government websites. These entities depend heavily on uptime and fast, reliable access to online services. An effective DDoS attack can cause service outages, financial losses, and damage to brand reputation. There are various types of DDoS attacks, including volumetric attacks, protocol attacks, and application-layer attacks. Volumetric attacks saturate the bandwidth of a system. Protocol attacks exploit weaknesses in layer 3 and layer 4 protocols, such as TCP, IP, and ICMP. Application-layer attacks target specific web functions such as HTTP, overwhelming the application with seemingly legitimate traffic. Preventing DDoS attacks involves a combination of proactive planning and technical solutions. Organizations should invest in scalable infrastructure and DDoS mitigation tools such as cloud-based filtering services, which can absorb large traffic spikes. Firewalls, routers, and load balancers must be configured to recognize and mitigate attack traffic. Real-time traffic analysis tools help distinguish between normal and malicious behavior. Deploying anomaly-based Intrusion Detection Systems (IDS) and Intrusion Prevention Systems (IPS) allows organizations to block suspicious IP addresses before they do damage. Rate limiting and geo-blocking can also reduce attack surfaces.

2. Phishing and Social Engineering

Phishing is a deceptive method that manipulates individuals into divulging sensitive information, such as login credentials or banking details. It usually occurs via email, but also extends to text messages (smishing), phone calls (vishing), and malicious websites. Attackers impersonate trusted entities like banks, service providers, or co-workers to deceive their targets. There are several types of phishing attacks, including spear-phishing, whaling, and clone phishing. Spear-phishing is highly targeted, often directed at a particular person or company. Whaling targets high-ranking executives, while clone phishing replicates a legitimate message but with malicious content. Social engineering encompasses a broader range of manipulative techniques beyond phishing. These can include pretexting (creating a fabricated scenario), baiting (offering something enticing), and tailgating (physically following someone into a restricted area). The common denominator is exploiting human psychology rather than technical vulnerabilities. The primary defense against phishing and social engineering is user education and awareness. Regular cybersecurity training ensures employees can identify red flags in communications. Simulation exercises can reinforce vigilance and encourage reporting of suspicious emails or requests. Technological safeguards are equally important in reducing phishing success rates. Spam filters, Domain-based Message Authentication Reporting and Conformance (DMARC), email encryption, and real-time URL scanners can intercept and quarantine malicious messages before they reach users.

3. Man-in-the-Middle (MitM) Attacks

Man-in-the-Middle (MitM) attacks occur when an attacker intercepts communication between two parties. This eavesdropping can result in data theft, session hijacking, and unauthorized access to accounts and systems. Common MitM techniques include packet sniffing, ARP spoofing, DNS spoofing, and HTTPS stripping. MitM attacks are particularly effective on unsecured networks, such as public Wi-Fi hotspots. Attackers can position themselves between the victim and the internet gateway to capture all transmitted data. Once inside the data stream, they can alter, read, or inject malicious content without the user’s knowledge. Session hijacking is a subset of MitM where attackers take over a valid user session. Once in possession of session cookies or tokens, they can impersonate the user and gain full access to web applications, often without requiring login credentials. Preventing MitM attacks requires a multi-layered approach that starts with encryption. Always use HTTPS for web browsing, SSH for secure remote login, and VPNs for secure tunneling. TLS (Transport Layer Security) ensures encrypted communication between clients and servers. Additional precautions include avoiding public Wi-Fi for sensitive transactions, using mobile network data instead, and verifying digital certificates. Employing tools like HTTPS Everywhere and turning off automatic connection to open networks can significantly reduce exposure.

4. SQL Injection

SQL Injection is a code injection technique used to exploit vulnerabilities in web applications. When a web application fails to properly validate or sanitize user input, attackers can inject malicious SQL code into input fields. This code manipulates the backend database to reveal sensitive information or perform unauthorized operations. The impact of a successful SQL Injection attack can be devastating. Attackers can retrieve entire databases, delete or alter data, and in some cases, gain administrative access to systems. High-profile breaches have occurred due to poorly protected web forms, search fields, and login pages. There are different types of SQL Injection, including in-band SQLi, blind SQLi, and out-of-band SQLi. In-band is the most straightforward, where attackers use the same communication channel to both launch and gather results from their attack. Blind SQLi relies on observing behavior rather than receiving direct output, while out-of-band uses alternate communication methods. To prevent SQL Injection, developers must adopt secure coding practices from the outset. The most effective measure is the use of prepared statements and parameterized queries, which separate data from code. This prevents user inputs from being interpreted as executable commands. Other preventive steps include input validation, using ORM libraries, and deploying Web Application Firewalls (WAFs). Regular code reviews, automated vulnerability scanners, and penetration testing should be part of every development cycle to catch and fix potential weaknesses early.

5. Cross-Site Scripting (XSS)

Cross-Site Scripting (XSS) enables attackers to inject malicious scripts into web pages that are then viewed by other users. These scripts execute in the victim's browser, allowing attackers to hijack sessions, steal cookies, redirect users, and spread malware. There are three main types of XSS: stored, reflected, and DOM-based. Stored XSS saves the malicious script on a server (e.g., in a comment field), where it’s served to other users. Reflected XSS embeds the script in a URL or form, which is then executed immediately upon being clicked. DOM-based XSS manipulates the Document Object Model of the page in the browser. XSS vulnerabilities are widespread due to dynamic content rendering and poor input handling. Any web application that processes and displays user-generated content is a potential target. Mitigation of XSS begins with robust input sanitization and output encoding. All user inputs should be treated as untrusted and cleaned before rendering. Encoding ensures that scripts are displayed as plain text rather than executed. Additional security measures include implementing Content Security Policies (CSP), escaping dynamic data in HTML, and enabling XSS protection headers. Security tools such as Snyk, OWASP ZAP, and Burp Suite can be used to scan for XSS vulnerabilities during development.