TYPES OF
ATTACKS CHEATSHEET.

By Target

• Web Applications (XSS, SQLi, CSRF)
• Network (MITM, DDoS, Sniffing)
• Endpoint (Malware, Ransomware)
• Human (Phishing, Social Engineering)
• Cryptographic (Brute Force, Hash Collision)

By Goal

• Data Theft / Exfiltration
• Denial of Service (DoS/DDoS)
• Privilege Escalation
• Information Disclosure
• System Compromise
• Financial Fraud

Cross-Site Scripting (XSS)

• Injects malicious scripts into web pages
• Types: Stored, Reflected, DOM-based
• Steals cookies, session tokens, user data
• Prevention: Input sanitisation, CSP, HTML encoding

<script>alert('XSS')</script>

// Prevention: HTML encode
<script>alert('XSS')</script> → &lt;script&gt;alert('XSS')&lt;/script&gt;

SQL Injection (SQLi)

• Injects malicious SQL queries via input
• Bypasses authentication, extracts data
• Can delete or modify database
• Prevention: Parameterised queries, ORM, input validation

// Example: SQLi
' OR '1'='1' --

// Query becomes:
SELECT * FROM users WHERE username='' OR '1'='1' --' AND password=''

// Prevention: Parameterised queries (JDBC)
PreparedStatement stmt = conn.prepareStatement(
    "SELECT * FROM users WHERE username = ? AND password = ?"
);
stmt.setString(1, username);
stmt.setString(2, password);

Cross-Site Request Forgery (CSRF)

• Forces authenticated user to perform unwanted actions
• Exploits trust of web application
• Changes password, funds transfer, etc.
• Prevention: CSRF tokens, SameSite cookies, re‑authentication

Command Injection

• Executes arbitrary system commands
• Input passed to shell without sanitisation
• Can compromise entire server
• Prevention: Avoid system() calls, sanitise input, use APIs

Path Traversal / Directory Traversal

• Accesses files outside web root
• Uses ../ sequences to navigate
• Exposes configuration, source code, passwords
• Prevention: Validate file paths, use whitelisting, chroot

Server-Side Request Forgery (SSRF)

• Abuses server to make requests to internal resources
• Accesses internal services, cloud metadata
• Can lead to data exfiltration
• Prevention: Validate URLs, block internal IPs, network segmentation

XML External Entity (XXE)

• Exploits XML parsers with external entities
• Reads local files, performs SSRF
• Can cause DoS
• Prevention: Disable external entities, use secure parsers

Insecure Deserialization

• Exploits deserialisation of untrusted data
• Leads to remote code execution
• Common in Java, PHP, Python, Ruby
• Prevention: Avoid deserialising untrusted data, use allowlists, integrity checks

Denial of Service (DoS / DDoS)

• Overwhelms system with traffic/requests
• Makes service unavailable
• Distributed (DDoS) uses multiple sources
• Prevention: Rate limiting, load balancing, CDN, WAF, traffic filtering
• Types: Volumetric, Protocol, Application layer

Man-in-the-Middle (MITM)

• Intercepts communication between two parties
• Eavesdrops, modifies, or impersonates
• ARP spoofing, DNS spoofing, SSL stripping
• Prevention: TLS/SSL, certificate validation, VPN, secure DNS

ARP Spoofing / Poisoning

• Falsifies ARP responses on local network
• Redirects traffic to attacker's MAC
• Used in MITM attacks
• Prevention: Dynamic ARP inspection, static ARP, network segmentation

DNS Spoofing / Cache Poisoning

• Falsifies DNS responses
• Redirects users to malicious sites
• Can lead to credential theft
• Prevention: DNSSEC, encrypted DNS (DoH/DoT), validate responses

Packet Sniffing

• Passively captures network packets
• Extracts sensitive data (passwords, tokens)
• Works on unencrypted or insecure protocols
• Prevention: Encryption (TLS), VPN, secure protocols (SSH, HTTPS)

IP Spoofing

• Forges source IP address
• Bypasses IP‑based authentication
• Used in DoS and MITM attacks
• Prevention: Ingress/egress filtering, authentication, cryptographic validation

Brute Force Attack

• Tries all possible combinations
• Targets passwords, encryption keys
• Time‑consuming for strong keys
• Prevention: Strong passwords, rate limiting, account lockout, MFA

Dictionary Attack

• Uses wordlist of common passwords
• More efficient than brute force
• Prevention: Password policies, MFA, salted hashing

Hash Collision Attack

• Finds two different inputs with same hash
• Compromises integrity and signatures
• Weak hash algorithms (MD5, SHA‑1) are vulnerable
• Prevention: Use SHA‑256, SHA‑3, strong hashing

Replay Attack

• Captures and resends valid data transmission
• Replays authentication, transactions
• Prevention: Nonces, timestamps, session tokens, TLS

Side‑Channel Attack

• Exploits physical implementation
• Timing, power consumption, electromagnetic leaks
• Spectre, Meltdown, timing attacks
• Prevention: Constant‑time algorithms, masking, hardware mitigations

Birthday Attack

• Exploits birthday paradox to find hash collisions
• Compromises digital signatures
• Prevention: Use larger hash output (SHA‑256/384/512)

Phishing

• Fake emails/websites pretending to be legitimate
• Steals credentials, personal information
• Types: Spear phishing (targeted), Whaling (executives), Vishing (voice), Smishing (SMS)
• Prevention: User education, email filtering, MFA, verify URLs

Pretexting

• Creates a fabricated scenario to extract info
• Impersonates authority figures, IT support
• Prevention: Verify identity, follow procedures, employee training

Baiting

• Offers something attractive to lure victim
• USB drives, downloads, free software
• Installs malware when used
• Prevention: Security awareness, USB lockdown, software sources

Tailgating / Piggybacking

• Follows authorised person into restricted area
• Physical security breach
• Prevention: Access control, security awareness, badge checks

Ransomware

• Encrypts files, demands ransom for decryption
• WannaCry, Ryuk, LockBit
• Spreads via phishing, exploits, RDP
• Prevention: Backups, updates, email filtering, network segmentation

Virus

• Self‑replicating, attaches to files
• Requires host file to spread
• Prevention: Anti‑virus, software updates, safe downloads

Worm

• Self‑replicating, spreads across network
• Does not need host file
• Conficker, Morris worm
• Prevention: Network segmentation, patch management, security monitoring

Trojan Horse

• Disguised as legitimate software
• Contains malicious code
• Prevention: Download from trusted sources, antivirus, code signing

Spyware / Adware

• Monitors user activity, steals information
• Displays unwanted ads
• Prevention: Antispyware tools, browser extensions, safe browsing

Rootkit

• Hides malicious code from detection
• Maintains privileged access
• Prevention: Security software, patch management, regular scans