Was Interplan hit by ransomware?

Interplan was listed by the worldleaks ransomware operation (Germany), and stolen data was published on the group's leak site. Darkfield tracks this disclosure with the original leak post, screenshot and group context.

Who is the worldleaks ransomware group?

worldleaks is a ransomware operator tracked by Darkfield. See the full operator dossier for its known victims, sectors targeted, IOCs and leak-site infrastructure.

What data was leaked in the Interplan breach?

worldleaks published data attributed to Interplan. Darkfield captured the leak post and a screenshot of the listing.

Ransomware victim disclosure

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Interplan

Claimed by Worldleaks · listed 4 months ago

Age

since listed · data leaked

Status timeline

ListedFeb 3, 2026
Data leakeddate unknown

At a glance

Group: Worldleaks
Status: Data leaked
Country: Germany
Listed on leak site: Feb 3, 2026

About the victim

AI dossier — public-source company profile

Interplan is a German professional congress and event management company headquartered in Munich, with additional offices in Hamburg, Berlin, and Leipzig. The company provides congress organisation, exhibition and sponsoring management, hotel services, participant management, DMC & event management, and association management services. With approximately 120 employees across four locations, Interplan serves medical, scientific, and professional associations across Europe.

Industry: Congress, Meeting & Event Management
Address: München, Hamburg, Berlin, Leipzig, Germany
Employees: 120

Attack summary

Severity: high — Data is marked as published (exfiltrated and released), and the company handles sensitive client data for medical congresses, government events (OSZE, G20), and professional associations across Europe, raising the likelihood that participant PII, contract data, and sensitive organisational records are involved.

The worldleaks group claims to have published data belonging to Interplan, with the disclosure status marked as data_published. The leak post description appears AI-generated and mischaracterises the company; no specific data types, encryption activity, or volume are detailed in the post.

high

Data the group says was taken

AI dossier — extracted from the leak post

Internal business data
Client and event records
Employee information
Association management files

Original description

AI-summarised, not from the leak post

Interplan is a leading international architecture and engineering firm that offers comprehensive planning and design services. Its services include the planning, development, and implementation of construction projects, covering various markets like hotels, nursing homes, and retail facilities. Their professional team brings together architects, interior designers, engineers, and planners to execute unique, efficient, cost-effective, and sustainable solutions for their clients.

Sources

Victim sitewww.interplan.de
Leak posthttps://worldleaksartrjm3c6vasllvgacbi5u3mgzkluehrzhk2jz4taufuid.onion/companies/9255855374

Source

Indexed 4 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.

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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 167 public disclosures across our corpus. First observed on a leak site on May 18, 2025; most recent post June 11, 2026. The operation is currently active.

Timeline of this disclosure

February 3, 2026Interplan listed by worldleakson the group's public leak site

Other recent disclosures by worldleaks

worldleaks has been linked to 167 public victims on Darkfield. A sample of the most recent:

See the full worldleaks dossier →

Sector and geography

Geographically, Interplan is reported in Germany, a country with 695 ransomware disclosures in our corpus.

If your organisation is affected

A listing by worldleaks means Interplan appeared on a ransomware extortion site and data attributed to it has been published. If this is your organisation, or a supplier you depend on, the priority is to confirm the intrusion and contain it before the window to act closes.

Engage your incident-response team and preserve forensic evidence before remediating — do not wipe affected systems first.
Force a password reset and revoke active sessions for exposed accounts; rotate any credentials, API keys or certificates that may have been in the stolen data.
Assess regulatory notification duties (GDPR, NIS2, sector regulators) — many carry a 72-hour reporting clock from awareness.
Monitor for the data appearing on worldleaks's leak site and across paste and breach channels, and brief downstream partners who may be exposed through you.

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.