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ISOSL

listed as isosl.be · Claimed by Apt73 · listed 3 months ago

2m
Age
since listed · data leaked

Status timeline

  1. ListedApr 27, 2026
  2. Data leakeddate unknown

At a glance

Group
Apt73
Status
Data leaked
Country
Belgium
Listed on leak site
Apr 27, 2026

About the victim

AI dossier — public-source company profile

ISOSL is a Belgian engineering company specialising in industrial solutions and automation. Based in Belgium, the company operates in the industrial engineering sector. Further details on scale and operations are not available from the provided sources.

Industry
Industrial Engineering & Automation

Attack summary

Severity: high — Data has been confirmed as published by the threat actor, indicating successful exfiltration of business data from an industrial engineering and automation company, which may include sensitive operational or proprietary technical information.

The group APT73 claims to have attacked ISOSL and has published data (disclosed status: data_published), suggesting exfiltration of company data, though specific details on encryption or precise data categories are not stated in the truncated post.

high

Data the group says was taken

AI dossier — extracted from the leak post
  • Industrial engineering data
  • Business operational data

What the group claims

ISOSL is an engineering company in Belgium, which deals with industrial solutions, automation and...

Sources

Source

Indexed 3 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 Apt73

APT73 is a recently emerged ransomware group that began operations in April 2024, with financial motivation as their primary driver based on their targeting patterns across multiple high-value sectors. The group has demonstrated rapid growth in their operational tempo, accumulating 78 documented victims within their first months of activity. Their targeting methodology shows a preference for English-speaking markets and major economies, with the United Kingdom and United States representing their primary focus areas, followed by significant activity in India, Brazil, and France. The group exhibits a clear preference for high-value sectors including business services, technology, financial services, and healthcare organizations, suggesting a calculated approach to victim selection based on potential payment capability and operational impact. Given the group's recent emergence and limited public documentation from major threat intelligence sources, specific details regarding their initial access vectors, tooling, encryption methods, or organizational structure remain largely unconfirmed by authoritative sources such as CISA, FBI, or established security research firms. The group's current operational status appears active based on the timeline of their emergence, though comprehensive analysis of their capabilities and infrastructure requires additional intelligence gathering and documentation by security researchers. The group has been linked to 161 public disclosures across our corpus. First observed on a leak site on April 22, 2024; most recent post July 6, 2026. The operation is currently inactive.

Also tracked as: Eraleign.

Timeline of this disclosure

  • April 27, 2026isosl.be listed by Apt73on the group's public leak site

Other recent disclosures by Apt73

Apt73 has been linked to 161 public victims on Darkfield. A sample of the most recent:

See the full Apt73 dossier →

Sector and geography

Geographically, isosl.be is reported in Belgium, a country with 44 ransomware disclosures in our corpus.

If your organisation is affected

A listing by Apt73 means isosl.be 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.
  • Report the incident to your national CERT, CERT.be (Belgium), as required for your jurisdiction.
  • Monitor for the data appearing on Apt73'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.