Common Cyber Threats

written by Dieter Smith, Wade Wells, Blake Regan, Matthew Thomas || Guest Authors

This article was originally published in the InfoSec Survival Guide: Green Book. Find it free online HERE or order your $1 physical copy on the Spearphish General Store.

In today’s interconnected digital world, information security has become a critical concern for individuals, businesses, and governments alike. Cyber threats, which encompass a wide range of malicious activities targeting information systems, pose significant risks to the confidentiality, integrity, and availability of data. Understanding these threats is essential for developing effective strategies to protect sensitive information and maintain cybersecurity.

Malware

Malware, or malicious software, is a broad category of cyber threats that includes viruses, worms, Trojans, ransomware, spyware, and adware. These programs are designed to infiltrate, damage, or gain unauthorized access to computer systems.

• Viruses attach themselves to legitimate programs and spread when these programs are executed. They can corrupt or delete data, slow down system performance, and disrupt operations.
• Worms are self-replicating programs that spread without user intervention, often exploiting vulnerabilities in network protocols.
• Trojans disguise themselves as benign software but carry malicious payloads, such as creating backdoors for remote access.
• Ransomware encrypts a victim’s data and demands a ransom for the decryption key, causing financial and operational disruptions.
• Spyware secretly monitors user activity, collecting sensitive information like login credentials and financial data.
• Adware displays unwanted advertisements and can track user behavior for marketing purposes.

Zero-Day Exploits

A zero-day exploit targets a vulnerability in software or hardware that is unknown to the vendor and has not yet been patched. Attackers exploit these vulnerabilities before developers can release a fix, making them particularly dangerous.

Insider Threats

Insider threats involve malicious or negligent actions by individuals within an organization, such as employees, contractors, or partners. These threats can result from intentional misconduct—such as data theft or sabotage—or unintentional actions, like falling for phishing scams or mishandling sensitive information.

Advanced Persistent Threats (APTs)

APTs are sophisticated, long-term cyberattacks often orchestrated by well-funded and skilled threat actors, including nation-states. These attacks aim to infiltrate and maintain access to networks to steal sensitive information or disrupt operations.

Social Engineering

Social engineering manipulates individuals into revealing confidential information or performing actions that compromise security. It exploits human psychology through tactics like impersonation and urgency. Social engineering targets trust and fear, emphasizing the need for awareness and education to counteract these deceptive strategies.

Phishing Attacks

Phishing is a social engineering attack where attackers deceive individuals into revealing sensitive information, such as usernames, passwords, and credit card numbers. This is typically done through fraudulent emails, messages, or websites that appear legitimate.

• Spear Phishing targets specific individuals or organizations with personalized deceptive communications, increasing the likelihood of success.
• Whaling is a form of spear phishing aimed at high-profile targets like executives or wealthy individuals.
• Vishing is voice-based solicitation where attackers mask their phone number to pose as a legitimate service and compromise credentials, credit card numbers, or identity information.
• Smishing uses fraudulent text messages (SMS) to trick recipients into providing personal information or clicking malicious links.

Denial of Service (DoS) & Distributed Denial of Service (DDoS) Attacks

DoS and DDoS attacks aim to make a service unavailable by overwhelming it with a flood of illegitimate requests. While a DoS attack originates from a single source, a DDoS attack uses multiple compromised devices to amplify the impact. These attacks can cause significant downtime, financial losses, and reputational damage.

Man-in-the-Middle (MitM) Attacks

Also known as Machine-in-the-Middle attacks—this occurs when an attacker intercepts and potentially alters communication between two parties without their knowledge. This can happen on unsecured Wi-Fi networks, compromised routers, or vulnerable communication protocols. MitM attacks can lead to data theft, unauthorized transactions, and compromised sensitive information.

Web-Based Threats

Web-based threats vary in complexity and often involve a user’s interaction with a compromised website or service.

• Cross-Site Scripting (XSS) involves injecting malicious scripts into web pages to steal data or hijack sessions.
• Drive-By Downloads automatically install malware on users’ devices through compromised websites or links.
• Browser Hijacking alters browser settings to redirect users to malicious sites or display unwanted content, often for ad revenue or phishing purposes.

SQL Injection

SQL injection is a code-injection technique in which attackers insert malicious SQL queries into input fields of a web application. If the input is not properly validated, attackers may manipulate the database, gain unauthorized access to data, modify or delete records, and potentially take control of the server.

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