What happened
In June 2026, on June 15, Troy Hunt's Have I Been Pwned (HIBP) added a new dataset called "June 2026 Stealer Logs." It contains hundreds of millions of records from infostealer malware, including:
- 56.3 million unique email addresses;
- 124 million unique passwords, which were added to Pwned Passwords and are now searchable.
Important: this is not a breach of one specific company. It is an accumulated collection of logs from various sources, generated by malware installed on the victims' own computers.
What "stealer logs" are
Infostealers are malicious programs that, once installed (via an attachment, a software crack, a fake extension or a malicious ad), collect everything they can from the browser and system: saved logins and passwords, session cookies, card data and crypto wallets. The data goes to the criminal and is then sold or shared on forums and Telegram channels.
That is why these logs are so dangerous: they usually bundle the site, the username and the password together, and sometimes session cookies that let attackers into an account without a password or 2FA.
How to check and what to do
- Individuals: search your email at haveibeenpwned.com. If it appears, the dashboard shows the stealer log records tied to it.
- Organizations: HIBP offers a stealer logs API by domain to see which corporate accounts appear.
If your email is listed, HIBP recommends:
- Change the affected password on every account where it was used.
- Enable two-factor authentication wherever possible.
- Use a password manager with unique passwords.
KGA IT's recommendations
Because the leak starts on the victim's own device, changing the password is not enough:
- Clean the computer first: run a trusted antivirus or reinstall the system. Changing a password on a still-infected PC hands the new one to the criminal.
- Sign out of all open sessions in email, social media and cloud services to invalidate stolen cookies.
- Prefer passkeys or security keys, which resist credential theft better.
- In companies: ban pirated software, control browser extensions and monitor the corporate domain in services like HIBP.
- Don't save work passwords in a personal browser.
Why it matters
Stealer logs have become one of the main entry points for attacks on companies: many large breaches start with a password or cookie stolen from an employee's computer. A dataset with 124 million unique passwords shows the scale of the problem.
Sources
- Have I Been Pwned, "June 2026 Stealer Logs": https://haveibeenpwned.com/Breach/June2026StealerLogs
Want to check whether your company's domain appears in leaks and protect your team's accounts? KGA IT offers a free consultation: kga-it.com.