Was Sabesp hit by ransomware?

Sabesp was listed by the Ransomhouse ransomware operation (Brazil), 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 Ransomhouse ransomware group?

Ransomhouse 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 Sabesp breach?

Ransomhouse published data attributed to Sabesp (~743 GB). Darkfield captured the leak post and a screenshot of the listing.

Ransomware victim disclosure

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Sabesp

Claimed by Ransomhouse · listed 2 years ago

743 GB

Data size

$740

Ransom

demanded

20m

Age

since listed · data leaked

Status timeline

ListedNov 1, 2024
Data leakeddate unknown

At a glance

Group: Ransomhouse
Status: Data leaked
Country: Brazil
Sector: Government
Listed on leak site: Nov 1, 2024
Data size: 743 GB
Ransom demanded: $740

About the victim

AI dossier — public-source company profile

Sabesp is Brazil's state-owned water and sanitation company serving the São Paulo metropolitan area and surrounding regions. It provides water supply, sewage collection, treatment, and disposal services to millions of residents across multiple municipalities in São Paulo state.

Industry: Water & Sanitation Utility

Attack summary

Severity: critical — Sabesp is critical infrastructure (water utility) serving millions; compromise of operational and customer data at 743 GB scale with confirmed exfiltration poses significant public safety and privacy risks. Affects essential services in a major Brazilian metropolitan area.

Ransomhouse claims to have encrypted Sabesp's systems and exfiltrated 743 GB of data. The group is demanding a $740 ransom and has published the breach on their leak site.

critical

Data the group says was taken

AI dossier — extracted from the leak post

operational systems data
customer records
financial records
administrative files
infrastructure documentation

What the group claims

In the name of our partners we apologize for the inconveniences that many people have to bear because of the incident. But we also want to explain the situation a bit more.First of all, the stories the Sabesp representatives tell you that they will restore their infrastructure are all lies.Our partners report that more than 2.000 servers were taken down and there are no chances those will be restored without our help as the company has no backups. If they had that data backed up, that would have already been restored.Taking into account the level of professionalism of the IT crew employeed in the company and the third parties the company has contracts with, restoration would take a minimum of 6 months or perhaps even more.With regard to company claims that no personal data was leaked, that's also not true. That was simply not disclosed yet.In addition to that, the company contacted us in the first days and we offered our help to solve the problem once and for all, but they've decided their money is more important than their clients and simple folk. At the same time we've received information they are taking a lot of cash out of the company for the purposes hardly related to solving the problem for people if you know what we mean.With our help the company infrastucture could be restored in 4-6 hours and everything could get back to normal the same day.The steps the company takes indicate that its management has no value for people and clients, the only things they have value for is money and profit, unfortunately.

The leak post

captured from the group's site

```
{"data":[{"id":"a1894b76b7004c75a3a0845799af49956592e3d9","display":"animated","header":"HOT NEWS","info":" Trellix is a global cybersecurity company.","url":"","sort":1,"views":"436242"},{"id":"336b257f582b17573c97578efd4b22762bf77344","sort":2,"header":"Trellix (McAfee & FireEye)","url":"https://www.trellix.com/","private":"false","revenue":"1.5-2 B$","employees":"5000","info":"Trellix is a global cybersecurity company formed from the October 2021 merger of McAfee Enterprise and FireEye. It provides services to over 50,000 business and government customers worldwide, protecting more than 200 million endpoints. The companys open and native extended detection and response (XDR) platform helps organizations confronted by todays most advanced threats gain confidence in the protection and resilience of their operations. Trellix, along with an extensive partner ecosystem, accelerates technology innovation through machine learning and automation to empower over 40,000 business and government customers with living security","statusDate":"DEPENDS ON YOU","status":"EVIDENCE","published":"NOT YET","action":"Encrypted","actionDate":"17/04/2026","volume":"~","content":"cybersecurity.html"…

Sources

Source

Indexed 2 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 Ransomhouse

Ransomhouse is a ransomware group that emerged in June 2021, operating primarily for financial gain through extortion campaigns targeting organizations across multiple sectors globally. The group's origin and specific affiliations remain unclear based on publicly available intelligence, though their operational patterns suggest they function as an independent cybercriminal organization rather than a traditional ransomware-as-a-service model. Ransomhouse employs double extortion tactics, stealing sensitive data before deploying their ransomware payload and threatening to publish the information on their leak site if victims refuse to pay the demanded ransom. The group has demonstrated a broad targeting approach, with documented attacks against 187 victims primarily concentrated in the United States, China, United Kingdom, Italy, and Spain, focusing heavily on healthcare, technology, business services, and manufacturing sectors. While specific high-profile campaigns have not been extensively documented by major security firms, the group's consistent victim count and geographic distribution indicate sustained operational capability since their emergence. As of current reporting, Ransomhouse remains active with no known major law enforcement disruptions or confirmed rebranding efforts. The group has been linked to 210 public disclosures across our corpus. First observed on a leak site on June 1, 2021; most recent post June 29, 2026. The operation is currently active.

Also tracked as: RANSOM HOUSE.

Timeline of this disclosure

November 1, 2024Sabesp listed by Ransomhouseon the group's public leak site

Data size: 743 GB
Ransom demanded: $740

Sector and geography

This disclosure adds to ransomware activity in the Government sector, which has 685 disclosures indexed across all operators we track. Geographically, Sabesp is reported in Brazil, a country with 404 ransomware disclosures in our corpus.

If your organisation is affected

A listing by Ransomhouse means Sabesp 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.br (Brazil), as required for your jurisdiction.
Monitor for the data appearing on Ransomhouse'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.