Insights & Resources

Somewhere on the dark web, right now, there is a marketplace selling stolen login credentials. Some of those credentials almost certainly belong to your employees. This is not speculation. It is a statistical near-certainty based on the scale of credential theft in recent years.

In 2025, infostealer malware stole 1.8 billion credentials, an 800 percent increase from the previous year. These infostealers infected 5.8 million devices, silently extracting saved passwords, browser cookies, session tokens, and financial information. The stolen data is packaged and sold on dark web forums, often within hours of theft, for as little as a few dollars per set of credentials.

For businesses, this creates a specific and urgent problem. If an employee’s work credentials appear in a dark web dump, attackers can use those credentials to access your email, cloud services, VPN, and internal systems. The breach does not start with a sophisticated hack. It starts with a login that looks completely legitimate because it uses real credentials.

Dark web monitoring is the practice of continuously scanning these criminal marketplaces for your organization’s exposed data so you can act before attackers do.

How Credentials End Up on the Dark Web

Understanding the supply chain of stolen credentials helps explain why the problem is so pervasive.

Infostealer Malware

Infostealers are lightweight malware programs designed to extract saved credentials from web browsers, email clients, and other applications. They run silently on infected devices, harvest every saved password, cookie, and autofill entry, and transmit the data to the attacker’s server. The entire process takes seconds.

Common infostealers like RedLine, Raccoon, and Vidar are sold as services on criminal forums for $100-300 per month. The barrier to entry is low, and the volume of stolen data is enormous.

Employees who save work passwords in their personal browser, use the same device for work and personal browsing, or download software from unofficial sources are all potential infostealer victims.

Data Breaches at Third-Party Services

When a service your employees use is breached, their credentials for that service are exposed. If they reused their work password on that service, which research shows the majority of people do, their work credentials are effectively compromised as well.

Major breaches at services like LinkedIn, Dropbox, and Adobe exposed hundreds of millions of credentials. Smaller breaches at niche services happen constantly and receive little media attention, but the credentials are equally valuable to attackers.

Phishing Campaigns

Credentials harvested through phishing campaigns are aggregated and sold in bulk on dark web marketplaces. A successful phishing campaign targeting your industry might capture credentials from dozens of businesses, all of which end up in the same marketplace.

Combolists and Credential Databases

Stolen credentials from multiple sources are compiled into massive databases called combolists. These databases contain billions of email-password pairs and are used for automated credential stuffing attacks against any service that accepts username and password authentication.

What Attackers Do with Stolen Credentials

Stolen credentials are not just collected; they are actively exploited, often within hours of appearing on the dark web.

Account takeover. Attackers use stolen credentials to log into email accounts, cloud services, and business applications. Once inside, they can read sensitive communications, access client data, and establish persistence for future attacks.

Business email compromise. A compromised email account is the perfect launching pad for BEC attacks. The attacker can read ongoing conversations, understand business relationships, and send fraudulent requests from a legitimate account.

Ransomware deployment. Stolen VPN or remote access credentials give attackers direct access to your internal network, where they can deploy ransomware, exfiltrate data, and move laterally to critical systems.

Data exfiltration. Access to cloud storage, file shares, and business applications allows attackers to steal sensitive data for sale, extortion, or competitive advantage.

Lateral movement. A single set of compromised credentials often leads to broader access. Attackers use the initial foothold to discover additional credentials, escalate privileges, and compromise additional systems.

How Dark Web Monitoring Works

Dark web monitoring services continuously scan criminal marketplaces, forums, paste sites, and data dumps for information associated with your organization. When your company’s data is found, you receive an alert with details about what was exposed and where it was found.

What is monitored:

• Email addresses associated with your domain appearing in breach databases and credential dumps
• Passwords paired with your company email addresses
• Session tokens and cookies that could allow account access without a password
• Company-specific data such as internal documents, client lists, or proprietary information
• Mentions of your company on criminal forums, which could indicate targeting or reconnaissance

What you receive:

• Alerts when new exposures are detected
• Details about which credentials were compromised and from what source
• Recommendations for immediate response (password resets, session invalidation)
• Trend reports showing your organization’s exposure over time

What to Do When Credentials Are Found

Discovering that your company’s credentials are on the dark web is not a reason to panic, but it is a reason to act immediately.

Force password resets. Any account whose credentials appear in a dark web dump should have its password reset immediately. Do not wait for the employee to do it voluntarily.

Invalidate active sessions. Changing a password does not terminate existing sessions. Revoke all active sessions for compromised accounts to ensure that stolen session tokens cannot be used for access.

Enable or verify MFA. If the compromised account does not have multi-factor authentication enabled, enable it immediately. If MFA is already enabled, verify that no unauthorized MFA methods have been added to the account.

Check for unauthorized activity. Review sign-in logs, email forwarding rules, and recent file access for the compromised account. Attackers who gain access often create persistence mechanisms like email forwarding rules or OAuth app consents that survive a password reset.

Investigate the source. Determine how the credentials were compromised. Was it a third-party breach? An infostealer infection? A phishing attack? Understanding the source helps prevent future exposures.

Beyond Monitoring: Reducing Your Exposure

Dark web monitoring is a detection control, not a prevention control. It tells you when credentials have been compromised, but it does not prevent the compromise from happening. A comprehensive approach combines monitoring with controls that reduce your exposure.

Enforce unique passwords. Deploy a business password manager that generates and stores unique passwords for every service. This eliminates password reuse, which is the primary reason that a breach at one service compromises access to others.

Deploy endpoint protection. EDR solutions detect and block infostealer malware before it can harvest credentials. Ensure that all devices that access company resources have current endpoint protection.

Implement phishing-resistant MFA. Even if credentials are stolen, MFA prevents them from being used for account access. Phishing-resistant methods like passkeys and FIDO2 security keys provide the strongest protection.

Restrict saved passwords in browsers. Configure endpoint policies to prevent work credentials from being saved in personal browsers, where they are vulnerable to infostealer extraction.

Monitor continuously. Dark web exposure is not a one-time check. New breaches and credential dumps appear daily. Continuous monitoring ensures that new exposures are detected promptly.

JayTec Solutions provides dark web monitoring as part of our comprehensive cybersecurity services. Combined with endpoint protection, MFA enforcement, and security awareness training, continuous credential monitoring closes the gap between when credentials are stolen and when your security team can respond.

The credentials are already out there. The question is whether you find out from a monitoring alert or from an attacker inside your network.