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A1 Group

listed as A1 · Claimed by Ransomed · listed 3 years ago

35m
Age
since listed · data leaked

Status timeline

  1. ListedAug 21, 2023
  2. Data leakeddate unknown

At a glance

Group
Ransomed
Status
Data leaked
Country
Austria
Sector
Technology
Listed on leak site
Aug 21, 2023

About the victim

AI dossier — public-source company profile

A1 Group is a leading telecommunications and ICT provider headquartered in Vienna, Austria, serving approximately 30 million customers across 7 core markets in Central and Eastern Europe. The company offers voice telephony, broadband internet, mobile and home entertainment, smart home, data and IT solutions, wholesale, payment solutions and digital services. It reported revenues of 5.6 billion EUR in 2025 and has been listed on the Vienna Stock Exchange since 2000.

Industry
Telecommunications & ICT Services
Address
Lassallestraße 9, 1020 Vienna, Austria
Employees
16000
Founded
2000

Attack summary

Severity: high — A1 Group is a major telecommunications operator with 30 million customers across 7 countries; a confirmed breach with data published against a company of this scale and sensitivity (customer PII, communications data) constitutes a high-severity incident, though the lack of specific data inventory detail and small disclosed proof prevents a critical rating.

The ransomed group claims a data provider breach against A1, noting that 1 of 4 partial payments was made on 2023-08-23, indicating a partial ransom payment was received. The post implies exfiltration of data with the 'data_published' status suggesting some data has been released.

high

Data the group says was taken

AI dossier — extracted from the leak post
  • Customer data
  • Business data

What the group claims

A1 Data Provider (1/4 partial payments have been paid on 2023-08-23)

Sources

Source

Indexed 3 years 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 ransomed

The ransomed ransomware group is a relatively new cybercriminal organization that emerged in August 2023, primarily motivated by financial gain through extortion activities targeting organizations across multiple countries. Based on their targeting patterns across Japan, Brazil, Russia, Great Britain, and Bulgaria, the group appears to operate internationally without clear geographic limitations, though their country of origin and potential affiliations with other ransomware groups remain undetermined due to limited public intelligence reporting. Given the recent emergence of this group and lack of detailed technical analysis from major security firms, their specific attack methodologies, initial access vectors, and encryption techniques have not been comprehensively documented in publicly available threat intelligence reports from CISA, FBI, or established security researchers. The group has claimed approximately 68 victims across their identified target countries since becoming active, though no specific high-profile campaigns or notable ransom demands have been publicly reported by law enforcement or security organizations. As of current reporting, the group appears to remain active with continued victim claims, though the limited public documentation suggests they operate as a lower-profile ransomware operation compared to more established and widely-tracked ransomware families. The group has been linked to 68 public disclosures across our corpus. First observed on a leak site on August 21, 2023; most recent post October 30, 2023. The operation is currently inactive.

Timeline of this disclosure

  • August 21, 2023A1 listed by ransomedon the group's public leak site

Other recent disclosures by ransomed

ransomed has been linked to 68 public victims on Darkfield. A sample of the most recent:

See the full ransomed dossier →

Sector and geography

This disclosure adds to ransomware activity in the Technology sector, which has 3,549 disclosures indexed across all operators we track. Geographically, A1 is reported in Austria, a country with 84 ransomware disclosures in our corpus.

If your organisation is affected

A listing by ransomed means A1 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.at (Austria), as required for your jurisdiction.
  • Monitor for the data appearing on ransomed'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.