If you’ve used the internet for more than a year, your email is probably in some breach corpus. The more interesting question in 2026 is whether you appear in fresh infostealer logs, credentials harvested by malware running on a real device, often within the last 30 days. Stealer logs are higher-impact than old breach data because the credentials are still active and frequently include valid session cookies. This is the tutorial for checking yourself, your family, or your domain.
Step 1: Check email exposure with Hudson Rock
Hudson Rock’s free tools are the cleanest starting point. Plug in any email address; their service tells you whether that email appears in their stealer-log corpus, with redacted preview of which services are affected.
Don’t ignore “yes” results, even if it’s an old infection. The credentials harvested at infection time may still be valid; the cookies definitely aren’t fresh anymore but accounts that haven’t rotated passwords are still at risk.
Step 2: Check domain exposure (corporate / employer)
Hudson Rock also offers a free domain check at the same URL, enter example.com and you get a count of infections across that domain’s employees. The detail page is gated; for the count alone, free is enough to know whether to escalate.
If you’re an admin and the count is non-zero, the next step is identifying which users and forcing credential rotation across them. That’s where the paid tier (or our own Stealercheck when it ships partner-data integration) comes in.
Step 3: Cross-check with IntelX
IntelX indexes paste sites, Tor pages, and public stealer-log dumps. Search your email, if it shows up in any indexed leak source, IntelX surfaces it with snippet preview and source. The free tier limits daily searches; sufficient for personal checks.
Different coverage from Hudson Rock, Hudson Rock focuses on infostealer-malware corpus; IntelX covers a broader set of leaked-data sources. Run both.
Step 4: Have I Been Pwned for breach context
Have I Been Pwned tells you which named breaches your email has appeared in over the years. Doesn’t cover infostealer logs (HIBP is breach-focused) but gives historical context for how exposed the email is generally. Free.
HIBP also has a free domain-monitoring service for owners of corporate domains, verify ownership via DNS or HTTP, get notified of every future breach including your domain. Set this up once for any domain you own.
Step 5: For higher-stakes monitoring, paid options
If you want monthly active monitoring instead of one-time checks:
- Hudson Rock Premium, full visibility into your domain’s infections, including which users, which credentials, which apps. Pricing on request.
- Flare, broader threat-intel platform that includes stealer-log monitoring, ransomware leak-site monitoring, and dark-web mention alerting. Mid-five-figures annually for SMB tier.
- Recorded Future, enterprise-grade. Six-figure annual contracts.
For most individuals, the free Hudson Rock + IntelX + HIBP combination is sufficient. For SMBs, Hudson Rock Premium or Flare. Enterprise should be running Recorded Future or Mandiant Threat Intelligence as part of a broader stack.
Step 6: When you find yourself in a log, what to do
Three actions, in order:
1. Find and clean the infected device. The infection is what created the log entry. If you don’t clean the device, every credential you rotate gets re-harvested. The Hudson Rock detail page (paid tier) tells you which device, typically by hostname and OS info captured by the malware. If you can’t identify the device, treat every machine you’ve used recently as suspect and run rebuilds.
2. Rotate credentials for every account in the log. Every saved password the malware harvested is in the log; rotate them all. Use a password manager to make this less painful.
3. Revoke active sessions. The cookies in the log can be replayed. Visit each major account’s “active sessions” page (Google, Microsoft, Apple, Facebook, your password manager) and sign out of every device. Then re-authenticate from the now-clean device.
Step 7: Make checking a habit
Set a calendar reminder for the first of every month. Five minutes, Hudson Rock check, IntelX check, HIBP check. The work compounds: catching exposure within 30 days of the leak is dramatically better than 18 months later when the credentials have already been used by three different criminal operations.
If you find yourself in a log: don’t panic. Most exposures are containable if you act within the day. The catastrophic cases are the ones nobody noticed for a year.