16 Billion Credentials Leaked — What to Do Right Now to Secure Your Accounts

by Zach’s Computer Services

A massive credential dump exposed roughly 16 billion login pairs across major platforms. If you reuse passwords or don't use two-factor authentication (2FA) or passkeys, act now — this guide explains the risks and exact steps to secure your accounts.

🔑 What happened and why it matters

A recent massive breach exposed roughly 16 billion email:password credential pairs. Attackers use these dumps for credential stuffing and account takeover attacks — testing leaked credentials across services to find reused passwords. For both individuals and businesses, even a small percentage of reused passwords can lead to account compromise and serious financial or reputational damage.

✅ Immediate actions to take (do these first)

• Check if your email addresses appear in known breaches using reputable breach-check tools and vendor breach notifications.
• Change any exposed passwords to unique, strong passwords you do not reuse across sites.
• Enable two-factor authentication (2FA) or passkeys on every account that supports them — prioritise email, banking, cloud storage, and social accounts.
• Use an authenticator app or hardware security key (FIDO2) instead of SMS-based 2FA where possible.
• Install and run reputable antivirus/anti-malware and ensure your devices are updated.
• Sign out of active sessions you don't recognize and revoke third-party app access.

🔑 How to enable 2FA and passkeys (practical guidance)

Most major platforms provide 2FA in account security settings. Prefer authenticator apps (TOTP) or hardware keys over SMS. Passkeys are the best option where supported — they replace passwords with cryptographic credentials and are phishing-resistant. For corporate environments, enforce phishing-resistant authentication via your identity provider and require hardware security keys for privileged accounts.

🧠 Stop password reuse — use a password manager

Password reuse is the single biggest factor making credential dumps dangerous. Use a reputable password manager to generate and store unique, complex passwords for every site. Most managers integrate with browsers and mobile devices to autofill credentials securely.

🏢 If a business account is exposed

• Immediately change passwords and enable phishing-resistant 2FA/passkeys.
• Rotate API keys, tokens, and service principals that may have been shared or stored with the account.
• Review access logs and MFA challenge/failure logs for unusual activity.
• Follow your incident response playbook and involve your security or IT team.

🧰 Prevention checklist (ongoing best practices)

• Adopt passkeys or hardware-backed 2FA for high-value accounts.
• Use a corporate password manager and enforce unique passwords across systems.
• Keep account recovery options secure and minimal — avoid shared or easily guessed recovery emails or phone numbers.
• Monitor for suspicious activity and set login alerts where available.

FAQ

Is changing my password enough?

Changing a compromised password is essential, but it should be unique and combined with enabling 2FA/passkeys and securing recovery options.

Are passkeys better than 2FA?

Passkeys provide stronger, phishing-resistant protection than most 2FA methods and are preferable where supported.

What if I can’t change a compromised password immediately?

At minimum, enable 2FA on the account, remove stored credentials from shared browsers, and monitor for suspicious activity until you can change the password.

Key takeaways

• 16 billion credentials were exposed — scale matters: attackers can automate credential stuffing at huge scale.
• Password reuse is the primary risk; stop reusing passwords and use a password manager.
• Enable 2FA or passkeys on every account that supports them — prefer authenticator apps and hardware keys over SMS.