Was Jakarta Nanyang School hit by ransomware?

Jakarta Nanyang School was listed by the tengu ransomware operation (Indonesia), 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 tengu ransomware group?

tengu 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 Jakarta Nanyang School breach?

tengu published data attributed to Jakarta Nanyang School. Darkfield captured the leak post and a screenshot of the listing.

Ransomware victim disclosure

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Jakarta Nanyang School

Claimed by Tengu · listed 5 months ago

Age

since listed · data leaked

Status timeline

ListedJan 26, 2026
Data leakeddate unknown

At a glance

Group: Tengu
Status: Data leaked
Country: Indonesia
Sector: Education
Listed on leak site: Jan 26, 2026

About the victim

AI dossier — public-source company profile

Jakarta Nanyang School is an international school located in Jakarta, Indonesia. Based on its name, it likely serves students of Chinese heritage or follows a curriculum with Chinese-language instruction, as 'Nanyang' is a common reference to Southeast Asia in Chinese cultural contexts. No public site content was available to confirm further operational details.

Industry: Education (International School)

Attack summary

Severity: high — The disclosure status is 'data_published', meaning data has been actively released rather than merely threatened. A school environment likely holds sensitive PII on minors (students), staff records, and potentially financial data, raising the severity. However, the absence of any stated data inventory, size, or proof details prevents a 'critical' classification.

The Tengu ransomware group has listed Jakarta Nanyang School under a 'data_published' status, indicating that data exfiltration and/or encryption occurred and data has been published. No specific data volume, ransom amount, or description of stolen data categories was provided in the leak post.

high

What the group claims

Jakarta Nanyang School (JNY) is a co-educational institution catering to students aged 3 to 18, offering a global and progressive educational approach. Established in 2012 in Bumi Serpong Damai, JNY focuses on the holistic development of students, enhancing their academic, moral, physical, social, and emotional growth. The school provides a nurturing environment and a variety of programs including Kindergarten, Primary, Secondary, and Junior College. JNY aims to serve families seeking a comprehensive and innovative educational experience for their children

The leak post

captured from the group's site

Shisa Ransomware Blog Shisa RANSOMWARE DATA LEAKS BLOG HOME AFFILIATE PROGRAM CONTACT crown-security.com.tw PUBLISHED Crown Security is a technology company specializing in information security and digital systems, offering advanced solutions to protect corporate networks and data from breaches and cyberattacks The company focuses on providing security consulting and implementing integrated protection systems tailored to each organization's needs 27,470 👁 Sileno Companies Inc PUBLISHED Sileno Companies Inc. A US company primarily operating in the hospitality and real estate sectors, its activities include: Hotel operation Property management Management of hotels' restaurants and bars Hospitality project development 22.9TB was encrypted in 14 hours on 3/5/2026 More than 67.07 GB was extracted 29,787 👁 Eos Technology srl PUBLISHED Eos Technology srl is a company with 15 years of experience in the ICT sector, initially starting as an assembly and repair laboratory for PCs and peripherals. Over time, it has developed expertise that has allowed it to become a partner of various international brands. The company offers a range of services including IT assistance, multimedia services, h…

Sources

Leak posthttp://longcc4fqrfcqt5lzceutylaxir6h66fp6df3oin6mvwvz6pfdbxc6qd.onion/blog/040c040c85339ebb4b2a8f8d865b4d2c5c83121b48c8dfde5436a78b113919fa/

Source

Indexed 5 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 tengu

Tengu is a recently emerged ransomware group first observed in October 2025, operating with apparent financial motivations and demonstrating a geographically diverse targeting approach across 49 documented victims. The group has primarily focused their operations on Morocco, the United States, India, Italy, and Indonesia, suggesting either opportunistic targeting or specific interest in these regions' economic sectors. Their victim profile spans multiple industries including technology, manufacturing, public sector, and agriculture and food production, indicating a broad targeting strategy rather than sector-specific focus. Due to the group's recent emergence and limited public documentation from established threat intelligence sources, specific details regarding their origin, affiliation status, technical methodology, encryption techniques, and operational structure remain largely undocumented by major cybersecurity agencies and research organizations. No notable high-profile campaigns or law enforcement actions have been publicly reported by CISA, FBI, or prominent security researchers at this time. The group's current operational status appears active given their recent emergence, though comprehensive threat intelligence profiles from established sources have yet to be published due to their nascent presence in the ransomware landscape. The group has been linked to 59 public disclosures across our corpus. First observed on a leak site on October 23, 2025; most recent post May 28, 2026. The operation is currently active.

Timeline of this disclosure

January 26, 2026Jakarta Nanyang School listed by tenguon the group's public leak site

Other recent disclosures by tengu

tengu has been linked to 59 public victims on Darkfield. A sample of the most recent:

See the full tengu dossier →

Sector and geography

This disclosure adds to ransomware activity in the Education sector, which has 694 disclosures indexed across all operators we track. Geographically, Jakarta Nanyang School is reported in Indonesia, a country with 23 ransomware disclosures in our corpus.

If your organisation is affected

A listing by tengu means Jakarta Nanyang School 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 tengu'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.