Was JLK Rosenberger hit by ransomware?

JLK Rosenberger was listed by the Incransom 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 Incransom ransomware group?

Incransom 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 JLK Rosenberger breach?

Incransom published data attributed to JLK Rosenberger (~300 GB). Darkfield captured the leak post and a screenshot of the listing.

Ransomware victim disclosure

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JLK Rosenberger LLP

listed as JLK Rosenberger · Claimed by Incransom · listed 5 months ago

300 GB

Data size

Age

since listed · data leaked

Status timeline

ListedJan 28, 2026
Data leakeddate unknown

At a glance

Group: Incransom
Status: Data leaked
Country: United States
Sector: Financial Services
Listed on leak site: Jan 28, 2026
Data size: 300 GB

About the victim

AI dossier — public-source company profile

JLK Rosenberger LLP is a full-service accounting and business advisory firm headquartered in California with offices in Irvine, Glendale, and Dallas, Texas. The firm is recognized as a Top 400 accounting firm by Inside Public Accounting and is one of the largest auditors of insurance entities in the United States, as ranked by Aon and AM Best.

Industry: Certified Public Accounting & Business Advisory
Address: Offices in Irvine, CA; Glendale, CA; and Dallas, TX, United States

Attack summary

Severity: critical — 300 GB of exfiltrated data from a large CPA firm includes client financial records and personal information at scale, which almost certainly contains regulated PII and sensitive financial data of both individuals and institutional clients (including insurance entities); data_published status and imminent publication threat compound the severity.

Incransom claims to have exfiltrated 300 GB of data from JLK Rosenberger LLP, including internal mail, accounting records, and customer information, and has threatened to publish all data imminently.

critical

Data the group says was taken

AI dossier — extracted from the leak post

Internal email communications
Accounting records
Customer/client information

What the group claims

JLK Rosenberger LLP, Certified Public Accountants: A full service accounting and business advisory firm with offices in Irvine and Glendale, California and Dallas, Texas. The firm is recognized as a Top 400 Firm by Inside Public Accounting and one of the largest auditors of insurance entities in the United States as ranked by Aon and AM Best We have 300GB of data. Internal mail, accounting, company customer information and we will publish all the information next week.

Sources

Leak posthttp://incblog6qu4y4mm4zvw5nrmue6qbwtgjsxpw6b7ixzssu36tsajldoad.onion/blog/disclosures/6975dbc68f1d14b7439a8b81

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 Incransom

Incransom is a ransomware group that emerged in August 2023, operating with primarily financial motivations as evidenced by their targeting of high-value sectors across multiple developed nations. The group's origin and specific affiliations remain undocumented by major threat intelligence organizations, though their operational patterns suggest they likely operate independently rather than as a ransomware-as-a-service model. With 734 documented victims, Incransom has demonstrated a preference for targeting organizations in the United States, Canada, United Kingdom, Germany, and Australia, with particular focus on healthcare, technology, business services, and manufacturing sectors, though their attack methodology and specific technical capabilities have not been extensively documented by established security researchers or government agencies. The group's notable campaigns and specific high-profile victims have not been publicly detailed by CISA, FBI, Mandiant, or other reputable threat intelligence sources, suggesting either operational security effectiveness or limited visibility into their most significant operations. Based on available intelligence, Incransom appears to remain active as of recent reporting periods, though comprehensive analysis of their current operational status requires additional documentation from established threat intelligence sources. The group has been linked to 829 public disclosures across our corpus. First observed on a leak site on August 9, 2023; most recent post June 11, 2026. The operation is currently active.

Also tracked as: inc ransom.

Timeline of this disclosure

January 28, 2026JLK Rosenberger listed by Incransomon the group's public leak site

Data size: 300 GB

Other recent disclosures by Incransom

Incransom has been linked to 829 public victims on Darkfield. A sample of the most recent:

See the full Incransom dossier →

Sector and geography

This disclosure adds to ransomware activity in the Financial Services sector, which has 516 disclosures indexed across all operators we track. Geographically, JLK Rosenberger is reported in United States, a country with 7,392 ransomware disclosures in our corpus.

If your organisation is affected

A listing by Incransom means JLK Rosenberger 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 Incransom'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.