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Cyber Threat
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Ransomware victim Technology

Sistel

Listed by Aoqin on · organisation based in Brazil

Disclosed
Nov 5, 2026
Leak-site listing date
Threat group
Aoqin
5 victims listed
Country
Brazil
#7 most targeted
Sector
Technology

ThreatAI analysis

Compiled from this incident record and the threat intelligence profile for Aoqin. Figures and technique mappings are quoted from the source data, not inferred.

About Sistel

Fundação Sistel de Seguridade Social offers a range of services including previdência (pension plans) and assistência médica (medical assistance) aimed at providing social security solutions. Their intended clients include individuals seeking financial security and healthcare support. The company also provides additional services such as loan simulations and preventive health packages. With a focus on user experience, they ensure access to a network of accredited healthcare professionals and facilities. Status: Not paid. Data publication: 2026-11-12 11:00 UTC. Revenue: $16M. Employees: 1. Data type: clientsData, confidential, personal.

Source record: ransomware.live

About the Aoqin group

Aoqin has listed 4 victims since November 2026.

Incident analysis

Sistel was listed by Aoqin ransomware, a group with 5 victims recorded in this database. The listing appeared on the group's leak site on November 5, 2026.

Sistel is based in Brazil and operates in the Technology sector. Brazil ranks #7 worldwide for ransomware disclosures, with 541 victims in this database.

Sector context. Technology companies hold intellectual property, customer data, and source code — all highly valuable assets. A successful ransomware attack can also put downstream customers at risk through supply chain exposure.

Aoqin typically follows a double extortion model: data is exfiltrated from the victim's systems before files are encrypted, so the victim faces two demands at once — pay to restore access, and pay to keep stolen data unpublished. The leak site, where this listing appeared, is the lever for the second demand.

Source. Public leak-site disclosures aggregated via the ransomware.live API. The disclosure date is when the listing was published, which can differ from the date of compromise. This site does not publish or link to stolen data. Last updated .

Frequently asked questions

Was Sistel attacked by ransomware?

Yes. Sistel was listed as a victim of the Aoqin ransomware group on November 5, 2026. The organisation is based in Brazil and operates in the Technology sector. The disclosure appeared on the group's dark web leak site.

Which ransomware group attacked Sistel?

Sistel was attacked by Aoqin ransomware. Aoqin is one of the most active ransomware groups, having claimed 5 victims globally. The group typically employs a double-extortion model: encrypting the victim's files and threatening to publish stolen data.

When did the Sistel ransomware attack occur?

The ransomware attack on Sistel was disclosed on November 5, 2026. This date reflects when the victim was published on the threat group's leak site, which may differ from the actual date of initial compromise.

What data was stolen in the Sistel ransomware attack?

The specific data stolen from Sistel has not been independently verified by this platform. Ransomware groups typically exfiltrate data before encrypting systems and use the threat of publication to pressure victims. As a Technology organisation, Sistel likely held source code, intellectual property, and customer data.

How can organisations protect against Aoqin attacks?

To defend against Aoqin and similar threat actors, organisations should: maintain regular offline backups tested for restoration; implement network segmentation to limit lateral movement; deploy multi-factor authentication on all remote access; use endpoint detection and response (EDR) tools; conduct regular phishing and security awareness training; and monitor threat intelligence feeds for indicators of compromise (IOCs) associated with active groups.