Was Probe Test System hit by ransomware?

Probe Test System was listed by the thegentlemen ransomware operation (Taiwan), 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 thegentlemen ransomware group?

thegentlemen 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 Probe Test System breach?

thegentlemen published data attributed to Probe Test System. Darkfield captured the leak post and a screenshot of the listing.

Ransomware victim disclosure

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Probe Test System Corp.

listed as Probe Test System · Claimed by Thegentlemen · listed 21 hours ago

Today

Age

since listed · data leaked

Status timeline

ListedAug 30, 2026
Data leakeddate unknown

At a glance

Group: Thegentlemen
Status: Data leaked
Country: Taiwan
Sector: Technology
Listed on leak site: Aug 30, 2026

About the victim

AI dossier — public-source company profile

Probe Test System Corp. (PTS, 群雅電子) is a Taiwanese semiconductor back-end service provider offering System Level Test (SLT), wafer chip probing, IC marking, Tape & Reel packaging, and inspection services. The company operates facilities in Miaoli County and serves major Taiwan-based chipmakers including Winbond, MediaTek, Novatek, Nuvoton and Macronix.

Industry: Semiconductor Testing & OSAT (Outsourced Semiconductor Assembly and Test)
Address: Zhunan and Toufen, Miaoli County, Taiwan (consolidated to Toufen as of Q1 2024)
Founded: 2000

Attack summary

Severity: medium — Data published status indicated, but no proof files, screenshots, or data inventory are described in the leak post. The target is a critical supplier to major chipmakers, which elevates concern despite lack of explicit proof disclosure.

The group claims to have compromised Probe Test System Corp. The leak post provides no specific details about the scope of the attack (encryption, exfiltration, or both) or what data categories are at stake.

medium

What the group claims

ptse.com.tw Probe Test System Corp. (PTS, 群雅電子) is a Taiwanese semiconductor back-end (OSAT) service provider operating since 2000, with plants in Zhunan and Toufen, Miaoli County (the former Hsinchu site was consolidated into Toufen in Q1 2024). Its services cover System Level Test (SLT), wafer chip probing (CP) on Chroma, ASL1000 and CTA8280 platforms, IC marking/remarking, Tape & Reel packaging (capacity ~150 KK units/month) plus lead/ball scan inspection. Long-term customers include Taiwan's leading chipmakers: Winbond, MediaTek, Novatek, Nuvoton and Macronix. The company is certified under ISO 9001, ISO 14001 and ANSI/ESD S20.20-2021.

Sources

Victim siteptse.com.tw

Source

Indexed 21 hours 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 thegentlemen

thegentlemen is a ransomware group that emerged in September 2025, operating with apparent financial motivations based on their broad targeting of commercial sectors. The group has documented 267 victims across multiple countries, with primary focus on the United States, Thailand, France, Brazil, and India. Their targeting strategy demonstrates a preference for high-value sectors including manufacturing, technology, healthcare, and financial services organizations. Given the group's recent emergence and limited public documentation from established threat intelligence sources such as CISA, FBI, or major security research firms, specific details regarding their country of origin, operational structure, attack methodologies, encryption techniques, and whether they employ ransomware-as-a-service models remain unclear. The relatively high victim count of 267 in a short operational timeframe since September 2025 suggests either an aggressive campaign pace or potential inflation of victim numbers through affiliate operations, though without corroborating intelligence reports, the group's exact operational capabilities and notable campaigns cannot be definitively established. Current intelligence indicates the group remains active as of late 2025, though comprehensive threat profiling requires additional validated reporting from authoritative cybersecurity sources. The group has been linked to 807 public disclosures across our corpus. First observed on a leak site on September 9, 2025; most recent post August 30, 2026. The operation is currently active.

Also tracked as: the gentlemen.

Timeline of this disclosure

August 30, 2026Probe Test System listed by thegentlemenon the group's public leak site

Other recent disclosures by thegentlemen

thegentlemen has been linked to 807 public victims on Darkfield. A sample of the most recent:

See the full thegentlemen dossier →

Sector and geography

This disclosure adds to ransomware activity in the Technology sector, which has 3,577 disclosures indexed across all operators we track. Geographically, Probe Test System is reported in Taiwan, a country with 58 ransomware disclosures in our corpus.

If your organisation is affected

A listing by thegentlemen means Probe Test System 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 thegentlemen'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.