What is a stealer log?
A stealer log is the complete data package infostealer malware exfiltrates from a single device. A breach dump is one field from one company’s database; a stealer log is device-level – every credential and live session token on the machine. That breadth makes logs the raw material for account takeover, ransomware, and fraud.
What a stealer log contains and how it circulates
Contents vary by malware family but typically include browser credentials across every installed browser, active session cookies (the most dangerous element – they bypass MFA), device fingerprints, crypto wallets, and email data. Once exfiltrated, a log moves through a layered economy:
- Malware operators (mostly Malware-as-a-Service) sell logs on darknet markets and private Telegram channels.
- Initial access brokers mine them for corporate VPN and RDP credentials to resell to ransomware affiliates.
- Fraud rings and credential stuffing operators take the banking credentials, cookies, and reusable pairs.
A single log can expose an employee’s corporate email, VPN, and SaaS sessions at once. To see how infostealer exposure translates into ransomware and account-takeover risk across industries, read the 2026 Annual Identity Exposure Report →
Why stealer logs are an enterprise problem, not a consumer one
The threat lives where your controls don’t reach, and the standard response under-remediates it:
- Unmanaged devices are the entry point. Logs land disproportionately on home laptops and personal machines your EDR never sees – yet they hold the corporate sessions employees use for work.
- No internal signal. A home infection can expose Microsoft 365, VPN, and Salesforce sessions with zero IT visibility into the event.
- A password reset isn’t enough. Logs carry live session cookies; the buyer keeps access until those sessions are explicitly killed.
- Remediate what was actually taken. SpyCloud Endpoint Threat Protection surfaces the full per-device exfiltration inventory so teams invalidate every exposed credential and session, not a guess.
Stealer logs vs. combolists
Both are sold in the same markets, but they’re different products with different risk profiles:
- A stealer log is device-level and context-rich – every credential, live session cookie, fingerprint, and accessed application from one machine. It’s the raw material.
- A combolist is the stripped-down derivative – just the username-password pairs, aggregated across many sources for bulk credential stuffing.
- Why the log is more dangerous: it carries the session cookies and device context a combolist throws away, enabling MFA-bypassing takeover rather than just a stuffing attempt.
If an employee’s device has been hit by an infostealer, the log may already be for sale.
Check Your Exposure to see what’s tied to your domain.
Frequently Asked
Everything an infostealer can pull from one device: saved browser usernames and passwords across all profiles, active session cookies and authentication tokens, autofill and form data, device and browser fingerprints, cryptocurrency wallets, and email or messaging data. The session cookies are the most dangerous component because they grant account access without the password and bypass MFA.
A breach dump comes from one company’s database and usually contains one data type for that single service, often hashed. A stealer log is device-level: all credentials, cookies, and data from one victim’s machine, spanning every service they used. Log credentials are also typically fresh and in plaintext, making them far more immediately usable than aged, hashed breach data.
Because infections frequently occur on personal and unmanaged devices your EDR never sees. A home computer infection can expose corporate sessions with no internal alert. Monitoring criminal markets for logs containing your domain is a detection layer that operates independently of endpoint security.