The Largest Credential Leak in History — and a Practical Guide to Help You Respond

In June 2025, researchers confirmed a breach of unprecedented scale: more than 16 billion credentials are now circulating on dark web markets.

These include logins for platforms your teams and vendors use daily — Microsoft 365, Apple, Google, VPNs, and core cloud tools.

This isn’t just a cybersecurity issue. It’s an operational risk that affects recovery, vendor reliability, and continuity planning. If you oversee business continuity or risk programs, this belongs at the top of your list.

What We Know: This Leak Is Massive, Current, and Already in Use

This leak isn’t recycled data. Most credentials were stolen recently through infostealer malware — malicious code that quietly captures logins from browsers and devices.

Affected platforms cover everything from enterprise systems to everyday productivity apps. Nearly every corner of the modern workplace is touched.

According to the 2025 Cyber Security Report, 61% of ransomware attacks last year began with stolen credentials. Attackers are using this data to gain entry, escalate access, and disrupt operations.

Why The Data Leak Matters to Continuity Leaders Like You

Credential leaks directly threaten your organization's ability to remain operational during crises. 

Here’s how:

• They enable silent entry into your environment, making it harder to detect and stop attackers before damage is done.
• They bypass your perimeter, especially if MFA isn’t enforced consistently across teams and vendors.
• They slow or block your response and recovery, especially when key accounts are hijacked or locked.
• They extend to your supply chain, making third-party risk harder to control and predict.

A data leak is a business continuity challenge, and the faster you respond, the better positioned your program will be.

How to Respond to a Credential Breach: A Practical 7-Step Guide

1. Assess and Investigate Potential Exposure

Use breach detection tools or dark web monitoring to confirm if employee or vendor credentials are exposed. Prioritize review of systems tied to those accounts.

2. Secure Privileged Access and Credentials

Immediately force password resets for critical roles and systems. Eliminate shared logins and ensure multi-factor authentication is enabled everywhere possible.

3. Work with IT to Remediate Systems

Coordinate cross-functionally to remove malware, block known malicious IPs, and patch systems that may have been exploited during the breach.

4. Update Your Continuity and Response Plans

Revise your business continuity and incident response plans to reflect credential-related threats. Test whether your current RTOs and RPOs can withstand an identity-driven disruption scenario.

5. Keep Stakeholders Informed and Aligned

Regularly brief legal, compliance, and executive leadership on the status of breach response, potential impacts, and any external communication obligations.

6. Revisit Training and Employee Behavior

Use this moment to reinforce credential hygiene and phishing awareness across your workforce. Focus on practical actions: unique passwords, password manager usage, and prompt reporting of suspicious activity.

7. Invest in Long-Term Visibility and Control

If you haven’t already, explore identity and access management tools that provide better insight into how credentials are used and misused across your environment. Consider expanding internal security capabilities or partnering with outside expertise.

Need a Starting Point? Use This Executive Guide

We developed The Largest Credential Leak in History: An Executive Guide to Protect Your Business to help continuity professionals respond with clarity, not chaos.

Inside, you’ll find:

• A short self-assessment to identify weak points in your current program.
• A practical roadmap for reducing identity-based risk.
• Guidance on how to adapt your business continuity strategy for this new class of threat.
• A framework to align with IT, security, and compliance teams

It’s designed to help you move quickly and confidently without overcomplicating the process.

This Breach Signals a Shift in Risk Management

Credential misuse is one of the fastest-growing threats to resilience. Whether the next attack starts inside your network or through a vendor, preparation is key.

A strong continuity program is your safety net — but only if it reflects today’s identity-driven risks.

Download the guide now and get ahead of credential-driven disruption.