DisclosureLens
GLOBALMalwareManufacturingManufacturingRansomwareStormRansom DemandedActor NamedData Leak ThreatenedData PublishedHigh

Otto Sieve GmbH

bd_4175f31bb7062d18 · schema v1 · pii pii-v2

Severity

High

Discovered

Filed

Aug 24, 2026

To disclose

Affected

Not disclosed

Confidence

50%
Full breach record for Otto Sieve GmbH

Threat-actor claim — not a regulatory filing

This row is a claim by the ransomware group Storm on its public extortion blog. It has not been validated by the victim or any regulator. Treat attribution and counts as the threat actor's assertion until a regulatory filing or victim disclosure corroborates them.

Group activity: ManufacturingDiscovered: 2026-08-27

Source: Ransomware.live

Post text · scraped from the leak site

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

Incident timeline — mostly unverified

? — ?

Breach window unknown

Aug 24, 2026

Claim posted

No filing yet · watching

Compliance clocks stay unassessable until a regulatory filing lands. Dashed segments fill in automatically when corroboration arrives.

Claim → filing

Compliance clock

Not assessable

Tracked as a single-filing incident — the only disclosure on record for this event so far.Unverified claimView incident

Evidence ladder

Leak-site claimThis record

Attacker assertion only. Establishes: claim date, group, alleged victim.

Press / market report

Unlocks: incident narrative, operational impact. Still no compliance clock.

State AG / regulator filing

Unlocks: discovery date, data types, affected count, compliance clock.

SEC 8-K / victim statement

Unlocks: materiality, stated response, full audit trail. Ceiling removed.

No regulatory filing corroborates this yet — it is the attacker's own assertion. Watch this entity to be notified the moment a filing corroborates or contradicts it.

Source ceiling

  • actor name
  • victim claim
  • ransom/leak status
  • discovery date
  • materiality
  • notification
  • affected count
  • confirmed data types
  • compliance clock

The ✕ fields stay blank until a regulatory filing or victim disclosure lands.

About this group

storm

56 victims claimed globally56 tracked hereFull profile →