Miljödata data breach: 870K accounts exposed
Severity: medium · Patch status: no-fix-needed · Since 2025-09-16
In August 2025, the Swedish system supplier Miljödata was the victim of a ransomware attack. Following the attack, data was subsequently published on the dark web and included 870k unique email addresses across various compromised files. Data also included names, phone numbers, physical addresses, dates of birth and government-issued personal identity numbers. Exposed data: dates of birth, email addresses, genders, government issued ids, names, phone numbers, physical addresses. The breach dates from Aug 25, 2025; Have I Been Pwned loaded it on Sep 16, 2025.
What to do
- If you had a Miljödata account, change its password and the password of any other account that reused it.
- Turn on multi-factor authentication wherever it is offered.
- Check whether your addresses are in this breach at https://haveibeenpwned.com.
- Expect targeted phishing that quotes the leaked details; verify any unexpected contact out of band.
Sources
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