A data breach occurs when someone gains unauthorised access to a computer system, network, or database and steals or exposes sensitive information. This stolen data typically includes personal details like names, addresses, email addresses, passwords, financial information, or health records belonging to customers or employees.
Data breaches happen through various attack methods:
- Phishing emails that trick staff into revealing credentials
- Weak or default passwords left unchanged
- Unpatched software vulnerabilities that attackers exploit
- Insider threats from disgruntled employees
- Physical theft of devices containing unencrypted data
- Man-in-the-middle attacks on unencrypted connections
Why this matters: A breach can lead to identity theft, financial fraud, reputational damage, and regulatory fines. In the UK, organisations must report breaches to the Information Commissioner's Office (ICO) within 72 hours if personal data is at risk, and face potential penalties under the Data Protection Act 2018.
Common gotchas: Many organisations underestimate breach risk, assuming their security is adequate when it isn't. Breaches often go undetected for months before discovery. A single weak link, such as an unpatched server or an employee using the same password everywhere, can compromise entire networks.
What you should do: Check whether your email address appears in known breaches using tools like Have I Been Pwned. Use unique, strong passwords for important accounts and enable two-factor authentication where available. For businesses, conduct regular security audits, keep software patched, and train staff on phishing awareness.