The Most Common Methods Behind Major Data Breaches
Data breaches have evolved in sophistication, but many attackers still rely on proven tactics to exploit vulnerabilities. Based on analysis of breaches from 2020–2025, here are the most prevalent methods used globally, along with real-world examples and statistics.

1. Credential-Based Attacks (37% of breaches)
Methods:
- Phishing: Fraudulent emails or messages trick users into revealing passwords.
- Brute Force: Automated tools guess weak passwords (e.g., "123456").
- Credential Stuffing: Reusing stolen credentials across platforms.
Statistics:
- 37% of breaches in 2024 involved credential theft (Verizon DBIR 2024).
- Stolen credentials cost companies $4.62M per breach on average (IBM, 2023).
Examples:
- 23andMe (2023): Hackers used credential stuffing to access 6.9 million accounts via reused passwords.
- Colonial Pipeline (2021): Attackers breached an employee’s VPN using a password found on the dark web.
2. Social Engineering (40% of breaches)
Tactics:
- Business Email Compromise (BEC): Impersonating executives to trick employees into wiring funds.
- Phishing: 16% of breaches start with phishing (IBM, 2024).
Impact:
- $4.76M: Average cost of phishing-related breaches (IBM).
- LinkedIn (2021): Hackers posed as recruiters to steal corporate credentials.
3. Exploiting Vulnerabilities (24% of breaches)
Common Weaknesses:
- Unpatched Software: Equifax’s 2017 breach stemmed from an unpatched Apache Struts flaw.
- SQL Injection: Injecting malicious code into databases (e.g., Heartland Payments, 2008).
Trends:
- Zero-Day Exploits: Accounted for $4.45M per breach in 2023 (IBM).
- MOVEit (2023): Russian hackers exploited a file-transfer tool to steal 60+ million records.
4. Ransomware (24% of Malware Breaches)
Process: Encrypt data and demand payment for decryption.
Costs:
- $4.91M: Average ransomware breach cost (IBM).
- Colonial Pipeline: Paid $4.4M in Bitcoin after a DarkSide ransomware attack halted fuel distribution.
Targets: Healthcare, education, and critical infrastructure.
5. Insider Threats (65% of breaches)
Types:
- Malicious Insiders: Employees selling data (e.g., Tesla staff leaking customer info in 2023).
- Negligence: Accidental exposure of sensitive files (e.g., misconfigured cloud storage).
Stats:
- Insider breaches take 85 days to contain (IBM).
- Meta (2024): Contractors improperly shared user data with third parties.
6. Physical Theft/Loss
Examples:
- Lost laptops or USB drives containing unencrypted data.
- Samsung (2022): A stolen device exposed proprietary chip designs.
Mitigation: Encryption reduces risk by 50% (Kaspersky).
7. Supply Chain & Third-Party Vulnerabilities
Attacks:
- SolarWinds (2020): Russian hackers compromised software updates to breach 18,000 organizations.
- Target (2013): HVAC vendor access led to 40M credit cards stolen.
Trend: 62% of breaches in 2024 involved third parties (Ponemon Institute).
8. Malware & Spyware
Common Tools:
- Keyloggers: Record keystrokes to steal passwords (e.g., Sony PlayStation breach, 2011).
- Spyware: Monitors user activity covertly.
Case: Marriott (2018): Chinese state actors used malware to steal 500M guest records over four years.
9. Cloud Misconfiguration
Impact:
- 80% of cloud breaches result from misconfigured storage buckets (Gartner, 2024).
- Exactis (2018): 340M records exposed via an unsecured Elasticsearch server.
10. Denial-of-Service (DoS) Attacks
Purpose: Disrupt services to distract from concurrent breaches.
- AWS (2020): A 2.3 Tbps DDoS attack masked a data exfiltration attempt.

Key Trends (2020–2025)
- Rise of AI-Driven Attacks: Phishing emails generated via ChatGPT increased by 135% in 2024.
- Global Regulation: GDPR fines hit €4B+ since 2018, pushing adoption of CCPA, LGPD, and DPDPA.
- Critical Infrastructure Focus: 45% of ransomware targets energy/healthcare sectors.
Prevention Strategies
- Zero Trust: Verify every access request.
- Multi-Factor Authentication (MFA): Blocks 99% of credential attacks (Microsoft).
- Employee Training: Reduces phishing success rates by 50% (KnowBe4).
As cybercriminals innovate, organizations must prioritize proactive defense to avoid becoming the next headline.
Sources: Verizon DBIR 2024, IBM Cost of a Data Breach 2023, Kaspersky, Gartner.
Citations:
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