Was Peaker Services hit by ransomware?

Peaker Services was listed by the sinobi ransomware operation (United States), 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 sinobi ransomware group?

sinobi 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 Peaker Services breach?

sinobi published data attributed to Peaker Services. Darkfield captured the leak post and a screenshot of the listing.

Ransomware victim disclosure

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Peaker Services

Claimed by Sinobi · listed 7 months ago

Age

since listed · data leaked

Status timeline

ListedDec 16, 2025
Data leakeddate unknown

At a glance

Group: Sinobi
Status: Data leaked
Country: United States
Sector: Manufacturing
Listed on leak site: Dec 16, 2025

About the victim

AI dossier — public-source company profile

Peaker Services, Inc. is a Brighton, Michigan-based company specializing in rebuilding, repairing, and maintaining diesel engines and related equipment for railroad, power generation, and marine sectors. The company designs, assembles, and installs generator, compressor, propulsion, and mechanical drive systems, as well as custom control systems, and distributes power generation and control equipment. It operates as a subsidiary of PSI Holding Company with facilities in Brighton, Michigan and New Castle, Delaware.

Industry: Diesel Engine Rebuilding & Industrial Power Systems Services
Address: Brighton, Michigan, United States (also facilities in New Castle, Delaware)
Founded: 1971

Attack summary

Severity: high — Data has been published (confirmed exfiltration) by the threat actor. The victim operates in critical infrastructure-adjacent sectors (railroad, power generation, marine), and the exfiltrated data likely includes sensitive business, engineering, and customer information. No regulated PII at scale is confirmed, preventing a critical rating.

The ransomware group sinobi claims to have attacked Peaker Services, Inc. and has published data (disclosed status: data_published), indicating exfiltration of company data, though no specific data volume or ransom amount was stated in the post.

high

Data the group says was taken

AI dossier — extracted from the leak post

Company operational data
Engineering and system design files
Customer records (railroad, power generation, marine sectors)
Contract and maintenance records
Business financial data

What the group claims

Peaker Services, Inc. engages in rebuilding, repairing, and maintaining diesel engines and related equipment for railroad, power generation, and marine companies. The company also designs, assembles, and installs systems used in generator, compressor, propulsion, and mechanical drive systems; designs and installs custom control systems; and provides emergency and custom repair, case and pan repair, component and assembly rebuilding, contract maintenance, inspection, and surveying services. In addition, it engages in the distribution of power generation and control equipment. The company was founded in 1971 and is based in Brighton, Michigan with facilities in Brighton, Michigan; and New Castle, Delaware. Peaker Services, Inc. operates as a subsidiary of PSI Holding Company.

Sources

Source

Indexed 7 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 sinobi

Based on the limited publicly available information, Sinobi appears to be a recently emerged ransomware operation first observed in July 2025, with financial motivations evidenced by their targeting of 268 victims across multiple sectors. The group's origin and specific affiliations remain undocumented in public threat intelligence reporting, and there is no confirmed information regarding whether they operate as a Ransomware-as-a-Service model or as an independent entity. Their attack methodology and technical capabilities have not been extensively documented by major security research organizations, though their targeting patterns suggest a broad opportunistic approach rather than highly selective operations. The group demonstrates a preference for targeting organizations in the United States, India, United Kingdom, Canada, and Italy, with a focus on manufacturing, healthcare, construction, and technology sectors, suggesting they may exploit common vulnerabilities across these industries rather than deploying sophisticated, sector-specific attack vectors. No major high-profile campaigns or significant law enforcement actions against Sinobi have been publicly reported by CISA, FBI, or established threat intelligence firms. Given the recent emergence timeline and lack of extensive public documentation, the group's current operational status and long-term trajectory remain unclear, though the substantial victim count suggests continued activity as of the last available reporting period. The group has been linked to 274 public disclosures across our corpus. First observed on a leak site on July 5, 2025; most recent post May 8, 2026. The operation is currently active.

Timeline of this disclosure

December 16, 2025Peaker Services listed by sinobion the group's public leak site

Other recent disclosures by sinobi

sinobi has been linked to 274 public victims on Darkfield. A sample of the most recent:

See the full sinobi dossier →

Sector and geography

This disclosure adds to ransomware activity in the Manufacturing sector, which has 3,681 disclosures indexed across all operators we track. Geographically, Peaker Services is reported in United States, a country with 11,033 ransomware disclosures in our corpus.

If your organisation is affected

A listing by sinobi means Peaker Services 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, CISA (United States), as required for your jurisdiction.
Monitor for the data appearing on sinobi'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.