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Stealer logs are packages of stolen data harvested by infostealer malware from infected devices. Each log contains credentials, cookies, and sensitive files from one victim. Criminals sell these logs on dark web markets and Telegram channels. Buyers use them for account takeover, fraud, and network intrusion.
When infostealer malware infects a device, it harvests everything valuable and sends it to attacker infrastructure. That stolen data becomes a “log” representing one compromised machine. Millions of these logs trade hands daily on criminal markets.
Understanding stealer logs matters because they’re the source of most credential exposure. Your employees’ passwords don’t just appear on the dark web randomly. They come from infected devices, packaged into logs, and sold to whoever pays.
What’s Inside a Stealer Log?
A typical stealer log contains everything the malware could extract from the infected device.
Browser credentials. Every username and password saved in Chrome, Firefox, Edge, and other browsers. Most people save dozens of passwords. One infection compromises them all.
Session cookies. Authentication tokens from active sessions. These bypass MFA because they represent sessions that already passed verification. Attackers use stolen cookies to hijack accounts without needing passwords.
Autofill data. Names, addresses, phone numbers, and payment card details stored in browser autofill. This enables identity theft and fraud beyond credential abuse.
Cryptocurrency wallets. Wallet files and browser extension data for Bitcoin, Ethereum, and other cryptocurrencies. Attackers can drain wallets immediately.
System information. Hardware IDs, installed software, IP addresses, and geolocation. This metadata helps buyers assess the log’s value and plan attacks.
Application credentials. Passwords from VPN clients, email programs, FTP applications, and messaging platforms. Corporate VPN credentials are especially valuable.
Where Are Stealer Logs Sold?
Stealer logs move through several channels on their way to buyers.
Telegram channels. Many operators distribute logs through private Telegram groups. Some channels offer free samples to attract buyers. Others run subscription services with daily log deliveries.
Dark web marketplaces. Dedicated markets like Russian Market and Genesis Market specialize in stealer logs. Buyers browse logs by country, domain, or specific services. Dark web markets operate like commercial platforms with search, filtering, and customer reviews.
Criminal forums. Hacking forums host sellers advertising bulk log packages. Prices vary based on log freshness, geographic location, and whether corporate credentials are included.
Direct sales. High-value logs containing corporate VPN access or admin credentials often sell privately. Initial access brokers purchase these logs, verify the access works, and resell to ransomware operators.
How Are Stealer Logs Priced?
Log pricing depends on what’s inside and how fresh the data is.
Consumer logs containing personal accounts sell for cents to a few dollars each. Bulk purchases of thousands of logs cost hundreds of dollars.
Corporate credentials command premium prices. A log containing VPN access to a mid-size company might sell for $50-500. Domain administrator credentials can fetch thousands.
Fresh logs are worth more than old ones. Credentials harvested yesterday are more likely to still work than those from months ago.
Geographic targeting affects price. Logs from wealthy countries with valuable banking and corporate targets cost more than those from regions with less financial infrastructure.
Why Do Stealer Logs Matter for Security Teams?
Stealer logs represent a direct path into your network.
Credentials appear before attacks. Stolen credentials circulate on criminal markets for days or weeks before attackers use them. This window is your detection opportunity. If you find exposed credentials while they’re being sold, you can reset them before exploitation.
Personal devices expose corporate access. Employees save work passwords in personal browsers. When their home computer gets infected, corporate credentials end up in stealer logs. Your endpoint protection doesn’t cover devices you don’t manage.
Session tokens bypass your defenses. Even with MFA enabled, stolen session cookies let attackers into accounts. They don’t trigger authentication alerts because the session is already validated. Only 33% of organizations terminate active sessions after detecting credential theft.
Ransomware starts here. According to Mandiant’s M-Trends 2025, stolen credentials are a top initial access vector for ransomware. Attackers buy VPN credentials from stealer logs, access your network, and deploy ransomware days or weeks later.
How Can You Detect Your Data in Stealer Logs?
Detection requires monitoring the sources where logs appear.
Monitor infostealer channels. Infostealer channel monitoring watches Telegram groups and markets where logs are distributed. When your domain appears in a log, you get alerted.
Search dark web markets. Automated scanning of criminal marketplaces catches credentials being sold. This detection happens while credentials are listed, before buyers exploit them.
Track by domain. Monitoring your corporate domains catches any employee credential that appears in logs. This works regardless of which device was infected or which infostealer harvested the data.
Check session exposure. Beyond passwords, monitor for exposed session tokens. These require immediate session termination, not just password resets.
What Should You Do When Credentials Appear in Logs?
Finding your credentials in stealer logs requires immediate action.
Reset passwords immediately. Don’t wait to investigate. Reset the exposed credentials first, then determine scope.
Terminate active sessions. Password resets don’t invalidate existing sessions. Force logout from all devices for affected accounts.
Assess the infection source. Determine which device was compromised. If it’s a corporate device, it needs forensic analysis. If it’s personal, the employee needs guidance on remediation.
Check for lateral movement. Review authentication logs for suspicious activity from the exposed accounts. Attackers may have already used the credentials.
Monitor for additional exposure. The same device may have exposed multiple credentials. Continue monitoring for your domains in stealer logs.
Conclusion
Stealer logs are the raw material of credential-based attacks. Every exposed password and session token in your organization likely came from one of these logs. Understanding what they contain and where they’re sold helps you detect exposure faster.
The window between credential theft and exploitation is your opportunity. Dark web monitoring catches stealer logs containing your credentials while they’re being sold.
Check if your credentials are already exposed with a free dark web scan.
Stealer Logs FAQ
A stealer log contains everything harvested from an infected device. This includes saved passwords from browsers, session cookies, autofill data, cryptocurrency wallet files, and system information. Each log represents one victim’s compromised data packaged for sale.
Logs typically appear within hours to days of infection. Infostealers exfiltrate data immediately after harvesting. Operators package logs and distribute them through Telegram channels or dark web markets. This speed creates a window where you can detect exposure before attackers exploit it.
Yes. Stealer logs contain session cookies captured after authentication. Attackers import these cookies to hijack active sessions without triggering MFA. This makes session tokens in stealer logs especially dangerous since password resets alone don’t invalidate them.
You need to monitor the markets and channels where logs are sold. Credential monitoring services scan stealer log sources for your domains and alert you when employee credentials appear. Without monitoring, you won’t know until attackers use them.
Data breaches expose credentials from compromised servers or databases. Stealer logs come from infected individual devices. Breach data is often older and passwords may already be changed. Stealer logs contain fresh credentials harvested in real-time, often including session tokens that bypass MFA.