Infostealers, explained.
From stolen session to breach.
Infostealers take saved passwords, cookies and session tokens from a device and sell them within hours. Learn how that trade works, why it slips past EDR and MFA, and check whether your domain is affected.
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Infostealers harvest credentials, cookies and session tokens straight from a device, then sell them on dark web forums and markets. Attackers buy that access and walk into your systems without a single phishing email being opened by an admin.
Where Passguard sits in an infostealer attack
From the first infection to the login without MFA, and the moment your team gets notified.
- Device infected An employee or contractor device, often unmanaged, runs a stealer.
- Log listed for sale Credentials and session tokens appear on a criminal marketplace.
- Passguard detects it here The listing is matched to your domain. Your team gets the alert, with the sessions to revoke.
- Attacker buys the session Valid tokens are bought within hours of listing.
- Logs in as your employee MFA bypassed. The stolen session walks straight into your systems.
Why infostealers slip past standard defences
EDR, MFA and breach monitoring each see part of the picture. The stealer trade happens in the gaps between them.
- Fact
- >95%of infostealer infections start on unmanaged devices
- Fact
- >1.8 milliondevices infected by stealers every month
- Fact
- Hoursbetween infection and the sale of the session
Everything about infostealers
From how stealers work to what NIS2 and DORA expect from you.
How infostealers work
What infostealers are, how they operate, and who is at risk.
Detection & monitoring
How to find infostealer infections and choose the right monitoring approach.
Attack mechanics
How infostealers spread, steal sessions, and sell access on criminal markets.
Prevention & response
What to do when an infostealer is active and how to reduce future risk.
Stealer families
Profiles of major infostealer malware families in active use.
Compliance
How infostealer risk maps to European regulatory frameworks.
The stealer trade, visible per domain.
The free scan only shows infostealer infections tied to your domain. The platform adds infostealer traces, target lists, password cracks, leaked accounts and breached accounts, with alerts by email and reports for management.
Explore the platform- Infostealer infectionsInfected devices, exposed sessions and infection context.
- Infostealer tracesCredentials found in ULP lists tied to infostealer activity, with source context.
- Target listsAccounts and identities found on target lists used in attack campaigns.
- Password cracksDehashed passwords found on password crack lists.
- Leaked accountsAccounts and credentials exposed in compilations, paste lists and other leaked datasets.
- Breached accountsAccounts and profiles exposed in third-party data breaches.
Everything you need to know
The essentials, explained in plain language.
Not answered here? Contact us
What are infostealers?
Infostealers are a type of malware that steals saved passwords, browser cookies, session tokens, and autofill data from infected devices. The stolen data is packaged into logs and sold on criminal marketplaces, giving attackers valid credentials that can bypass MFA. Read our full guide in the Infostealer Wiki.
Will Passguard work with our existing security stack?
Yes. Passguard requires no integration or installation, so it complements your current security tools without adding workload for your IT team.
Don’t our EDR tools already pick up infostealers?
In most cases they do not. Infostealers typically spread through unmanaged or personal devices that fall outside the reach of traditional EDR solutions.
How quickly can we start seeing results?
You see results immediately. After adding your domains, Passguard shows all historical infections linked to your company and then continues monitoring for new ones.
Does MFA protect us against infostealers?
Only partly. MFA stops an attacker who has just a password. Infostealers also take the browser cookies and session tokens created after a successful login, so the attacker replays a session that already passed MFA. Revoking the exposed sessions closes that door, which is why Passguard shows exactly which sessions to revoke.
What should we do after an infostealer infection?
Revoke the exposed sessions and reset the credentials found in the log, then isolate and clean the device. Check which services the stolen sessions gave access to and review recent logins there. Passguard shows the device, the malware family, the accounts and the sessions per infection, so the response is a checklist rather than a search.