Blackout
Since Feb 26, 2024, Blackout has listed 12 organizations on its leak site.
Listings per month
- Total listings
- 12
- First listing
- Feb 26, 2024
- Latest listing
- Jul 19, 2026
- MITRE ATT&CK techniques
- 0
Blackout is a ransomware group that first appeared in early 2024, initially claiming attacks against healthcare entities in Canada, France, and Germany before expanding to telecommunications, mining, and manufacturing sectors, operating a double-extortion model with a data leak site.
It posted 3 listings in the last 12 months; the busiest month was July 2026 (3 listings).
Most targeted country: Greece, with 2 listings (17% of the total).
Most targeted sector: Healthcare, with 3 listings (25% of the total).
Showing 10 of 12 results
What does a ransomware group do?
Ransomware groups break into corporate networks, move data out and encrypt systems. If the ransom is not paid, they list the organization on a leak site and threaten to publish the data.
What should you do if your organization is listed on a leak site?
- Record the listing and any published sample files; do not visit the leak site from the corporate network.
- Isolate affected systems and preserve logs without deleting them.
- Determine which data left the organization; if personal data is involved, review notification obligations with your legal team.
- Make any decision about the ransom demand together with legal, management and incident response.
- Do not bring systems back online before the attacker’s entry point is closed.
Is your organization mentioned?
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