Cyber-attacks are becoming increasingly common as more of our lives move online. From individuals to businesses to governments, no one is immune from cyber threats. Understanding the most prevalent types of cyber-attacks can help equip us to better defend against them.
Here we will explore the 10 most common categories of cyber-attacks and provide examples of each:
1. Phishing
Phishing is one of the most common and dangerous cyber threats today. It involves attackers masquerading as trustworthy entities in order to trick victims into revealing sensitive information. Phishing attacks typically occur via email, instant message, text message, or fraudulent website. The message will often appear to come from a legitimate organization and request personal information such as login credentials or credit card details. Examples of phishing include:
- An email that looks like it’s from your bank, asking you to verify personal account information
- A text message that appears to be from a package delivery company with a link to track your shipment, but leads to a fake site that collects your data
- A fraudulent customer support line that asks for your password to “verify your account”
Phishing is especially dangerous because it relies on social engineering rather than technical hacking to take advantage of unwitting victims.
2. Denial-of-Service (DoS) Attacks
Denial-of-Service (DoS) attacks aim to overwhelm websites and online services by flooding them with more traffic than they can accommodate. This disrupts legitimate access and functionality. DoS attacks can cost organizations significant revenue due to downtime and blocked traffic.
Some examples of DoS attacks include:
- Ping floods that overwhelm a network with countless small data packets
- SYN floods that send high volumes of TCP connection requests
- HTTP floods that bombard a site with fake browsing requests
- Perpetual attacks from botnets that continuously send requests from millions of infected devices
DoS attacks have grown larger and more complex over time. Attacks exceeding 1 Tbps are not uncommon today.
3. SQL Injection
SQL injection involves inserting malicious code into web inputs like login fields or URLs. Attackers use it to gain unauthorized access to the database behind a website or application. From there, they can steal and expose sensitive information.
Some examples of SQL injection attacks include:
- Entering additional SQL queries into login fields, allowing access to user accounts
- Using UNION SQL keywords to combine queries and extract information not normally accessible
- Inserting server-side code into inputs to manipulate site behavior
SQL injection remains one of the most common attack vectors today due to the widespread use of relational databases behind web applications.
4. Cross-Site Scripting (XSS)
Cross-site scripting, also known as XSS, is an attack that injects malicious client-side code into web pages. This code is then executed by victims’ browsers to hijack sessions, deface sites, insert unwanted content, and more. XSS attacks exploit vulnerabilities in how a website handles user-supplied data.
Some examples of XSS attacks include:
- Stored XSS that permanently injects malicious JavaScript into databases shown on a website
- Reflected XSS that delivers malicious code via malformed links
- DOM-based XSS that corrupts Document Object Models on the client-side browser
XSS attacks are very common due to the prevalence of JavaScript and lack of input validation on many sites. Attackers often use XSS to steal session cookies or deploy spyware.
5. Man-in-the-Middle Attacks
Man-in-the-middle (MitM) attacks insert attackers into a two-party transaction. Attackers then covertly eavesdrop and possibly alter communications between the victims. Examples include:
- Wi-Fi eavesdropping whereby attackers intercept connections on public networks
- BGP hijacking that corrupts Internet routing to divert traffic through attackers
- SSL spoofing that allows encrypted web traffic to be intercepted
MitM attacks allow perpetrators to steal login credentials, financial data, trade secrets and more. They capitalize on unsecured public Wi-Fi, unencrypted web connections, and vulnerabilities in routing protocols.
6. Drive-By Downloads
Drive-by downloads refer to unintentional file downloads that occur when visiting a website. Attackers embed malicious code into legitimate sites that automatically triggers downloads in visitors’ browsers. Examples include:
- Installing spyware or backdoors when a user visits a compromised site
- Hijacking browser settings by exploiting plugin vulnerabilities
- Downloading malware by redirecting users to malicious sites via ads
Drive-by downloads take advantage of vulnerable browsers, plugins, and extensions as well as lax ad vetting procedures. They enable attackers to gain backdoor access without victims noticing.
7. Password Attacks
Attackers have many tools at their disposal to crack users’ passwords. Some approaches include:
- Password spraying which systematically tests common passwords against many accounts
- Dictionary attacks that try passwords from precompiled lists
- Brute force attacks that exhaust all possible password combinations
- Rainbow table attacks with databases of precomputed hash-password pairings
Weak and reused passwords leave users extremely vulnerable to these attacks. Multifactor authentication provides an important safeguard by requiring additional credentials beyond just a password.
8. Malware
Malware refers to malicious software designed to infiltrate and damage devices and systems. Some of the most common malware threats include:
- Viruses that self-replicate by infecting other files or programs
- Trojans that disguise themselves as legitimate software
- Spyware that gathers data like browsing history, logins, and financial information
- Ransomware that encrypts data until ransom is paid
- Botnets powered by malware that conscripts devices into attacking other systems
Malware can delete data, corrupt systems, relay sensitive information, and enable further breaches. It poses one of the most sophisticated digital threats given the many forms it can take.
9. Insider Threats
Insider threats refer to risks posed by malicious actors within an organization. These include employees, contractors, partners, and others with inside access. Examples of insider threat attacks include:
- Intentional data theft or leakage for financial gain or espionage
- Unintentional mishandling of data such as incorrect permissions or misplaced devices
- Sabotage aimed at disrupting business operations
- Collusion with external attackers providing access to sensitive systems
Insider threats often evade security measures focused on external risks. Tracking access, limiting permissions, and monitoring behavior are key to mitigating insider risks.
10. Supply Chain Attacks
Supply chain attacks target less secure vendors, suppliers, or partners to breach the ultimate target through its weaker links. Examples include:
- Compromising software developer tools and processes to inject vulnerabilities into downstream customer installations
- Injecting malware into hardware components during manufacturing to access customer data
- Impersonating vendors to hijack their credentials and access customer environments
Supply chain attacks move through networks of interconnected entities to obscure their source and exploit trust relationships. Securing partner access and software authenticity helps counter this threat.
Conclusion
These 10 categories encompass some of the most prevalent cybersecurity threats facing individuals, businesses, and organizations today. Raising awareness of these attack techniques is crucial for effective defense. Key protective measures include:
- Implementing security awareness training to recognize threats like phishing and avoid behaviors that enable attacks
- Updating software regularly to patch vulnerabilities that many attacks capitalize on
- Installing security tools like antivirus, firewalls, and intrusion detection systems to block and identify threats
- Enabling multifactor authentication to augment password security
- Monitoring networks and systems vigilantly for signs of compromise
- Developing comprehensive incident response plans to contain and remediate damage from successful attacks
Cybersecurity threats will continue to evolve, requiring adaptable defenses. But understanding the most common attack categories provides a strong foundation for individuals and organizations to protect themselves.