Otto Sieve GmbH
StormThis record tracks a ransomware attack claimed by the Storm group against Otto Sieve GmbH. It collects the publicly disclosed attack details — sector, location and timeline — as published on the operator's leak site and indexed by Breach House.
Window Zero
EXPOSURE GAPWindow Zero is the time the breach stayed in the open before anyone said so — the gap between when the attack was first discovered on the operator's leak site (t1) and when it was publicly disclosed (t2). The wider this window, the longer victims, staff and customers were exposed with no warning.
Attack Summary
Otto Sieve GmbH is a family-owned German company specializing in building services and modern home technology. Founded in 1967, the company provides heating, ventilation, sanitary, solar, and renewable energy solutions. Its services cover the planning, installation, maintenance, repair, and modernization of heating systems, bathrooms, heat pumps, solar technology, ventilation, and related building systems. Otto Sieve serves customers involved in new construction, renovation, and modernization projects and also provides maintenance and emergency repair services. The company emphasizes energy-efficient, sustainable solutions, technical expertise, personal consultation, and high-quality workmanship. Its headquarters is in Lohne, Lower Saxony, Germany. The company headquarters is located in Lindenstraße 102a, 49393 Lohne, Germany. 11-50 Employees
Leak Screenshots
SAMPLEProof-of-breach screenshots the operator posted from the stolen data. Previews are redacted and locked — the originals are available on HaveIBeenRansom.