Disclosure context

About worldleaks

Based on the limited available data, worldleaks is a recently emerged ransomware group that was first observed in May 2025 and appears to be primarily financially motivated, having claimed 134 victims in a relatively short timeframe since its emergence. The group's origin and organizational structure remain unclear, with no publicly documented information from major cybersecurity firms or law enforcement agencies regarding their country of origin, potential affiliations, or operational model. Their targeting patterns indicate a focus on English-speaking countries, particularly the United States, United Kingdom, and Canada, with additional activity observed in Germany and Japan, while their sector targeting shows a preference for healthcare, technology, manufacturing, and consumer services organizations. Due to the group's recent emergence and limited public documentation by established threat intelligence sources, specific details about their attack methodologies, encryption techniques, extortion tactics, and notable campaigns have not yet been comprehensively analyzed or reported by organizations such as CISA, FBI, or major cybersecurity research firms. The group appears to remain active as of the most recent observations, though comprehensive threat intelligence profiling awaits further analysis and documentation by established cybersecurity authorities. The group has been linked to 155 public disclosures across our corpus. First observed on a leak site on May 18, 2025; most recent post May 12, 2026. The operation is currently active.

Timeline of this disclosure

April 1, 2026AMBAU Personalservice listed by worldleakson the group's public leak site

Sector and geography

This disclosure adds to ransomware activity in the Business Services sector, which has 2,640 disclosures indexed across all operators we track. Geographically, AMBAU Personalservice is reported in DE, a country with 333 ransomware disclosures in our corpus.

How we know this. Darkfield monitors public ransomware leak sites continuously, archiving every new disclosure and the data later released against the victim. Each entry on this page is sourced from the operator's own publication and cross-checked against complementary OSINT feeds (RansomLook, ransomware.live, RansomWatch). We do not collect or host stolen data — only the metadata, timestamps and screenshots needed to make the public disclosure searchable and accountable. Records here are corrected when the original post is edited, retracted, or merged with another disclosure.

Ransomware victim disclosure

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AMBAU Personalservice

Claimed by worldleaks · listed 2 months ago

49d

Age

since listed · data leaked

Status timeline

Listed
Apr 1, 2026
Data leaked

At a glance

Group: worldleaks
Status: Data leaked
Country: DE
Sector: Business Services
Listed on leak site: Apr 1, 2026

About the victim

AI dossier — public-source company profile

AMBAU Personalservice is a German staffing and recruitment company with over 30 years of experience, offering temporary staffing (Arbeitnehmerüberlassung), permanent placement, and coaching services. The company specialises in commercial and industrial personnel across sectors including steel and plant construction, wind turbine construction, and power plant engineering. It operates from five locations across Germany: Ludwigsfelde (headquarters), Wittenberg/Jessen, Bremen, Cuxhaven, and Berlin.

Industry: Staffing & Temporary Personnel Services
Address: Seestraße 35, Brandenburg Park, 14974 Ludwigsfelde, Germany

Attack summary

Severity: high — As a staffing agency, AMBAU holds significant volumes of personally identifiable information for both employees and job applicants (names, addresses, employment history, potentially tax/payroll data), as well as client company data. The disclosed status of 'data_published' indicates actual exfiltration and release of this sensitive PII, elevating the risk to affected individuals and client firms.

The worldleaks group claims to have published data belonging to AMBAU Personalservice, with the disclosed status indicating data has been released rather than merely threatened. No specific details on encryption or the precise nature of exfiltrated data are stated in the post.

high

Data the group says was taken

AI dossier — extracted from the leak post

Employee records
Applicant/candidate data
Payroll and compensation information
Client company HR data
Internal business correspondence
Financial/controlling records

Original description

AI-summarised, not from the leak post

AMBAU Personalservice is a staffing and recruitment company based in Germany. It specializes in providing highly skilled personnel across various industries including construction, industry, logistics, and traffic fields. Their services cater to both temporary and permanent staffing needs. The company is known for its effective, comprehensive services encompassing the full cycle of recruitment, placement, and employee management.

Sources

Victim sitewww.ambau-team.de
Leak posthttps://worldleaksartrjm3c6vasllvgacbi5u3mgzkluehrzhk2jz4taufuid.onion/companies/2617010624

Source

Indexed 2 months ago

This page surfaces a public ransomware disclosure indexed by Darkfield. Original posts come from the operator's own leak site; we cross-check against ransomware.live, RansomLook and RansomWatch where applicable. Share this URL freely.