Disclosure context

About genesis

Genesis is a recently emerged ransomware group that was first observed in October 2025, operating with apparent financial motivations based on their targeting patterns across multiple high-value sectors. The group has demonstrated a relatively aggressive operational tempo since emergence, accumulating 54 documented victims within a short timeframe. Given the limited public documentation available from established threat intelligence sources regarding this newly identified group, specific details about their country of origin, organizational structure, and precise attack methodologies remain under investigation by security researchers. The group's targeting patterns indicate a preference for victims in the United States and United Kingdom, with additional activity observed in Malaysia and Spain, suggesting either a broad operational scope or the use of automated targeting tools that do not discriminate by geography. Their sector targeting reveals a focus on healthcare, manufacturing, business services, and financial services organizations, indicating they may prioritize entities with both high revenue potential and critical operational dependencies that increase pressure for ransom payment. Due to the group's recent emergence and limited reporting from major threat intelligence organizations such as Mandiant, CISA, or FBI, comprehensive details regarding their specific encryption methods, initial access vectors, data exfiltration practices, or notable high-profile campaigns have not yet been publicly documented. Genesis remains an active threat as of current reporting, though their operational longevity and potential connections to established ransomware ecosystems continue to be assessed by the cybersecurity community. The group has been linked to 82 public disclosures across our corpus. First observed on a leak site on October 21, 2025; most recent post May 19, 2026. The operation is currently active.

Timeline of this disclosure

May 18, 2026HostBooks listed by genesison the group's public leak site

Data size: 500 GB

Sector and geography

This disclosure adds to ransomware activity in the Software/Accounting sector.

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.

Ransomware victim disclosure

← All victims

HostBooks

Claimed by genesis · listed 3 days ago

500 GB

Data size

Age

since listed · data leaked

Status timeline

Listed
May 18, 2026
Data leaked

At a glance

Group: genesis
Status: Data leaked
Sector: Software/Accounting
Listed on leak site: May 18, 2026
Data size: 500 GB

About the victim

AI dossier — public-source company profile

HostBooks is an accounting software provider founded in 2009. The company offers a cloud-based platform encompassing cloud accounting, expense management, invoicing, reconciliations, inventory management, financial reporting, and a client management portal. It serves businesses requiring integrated financial and operational software tools.

Industry: Accounting Software (SaaS/Cloud)
Founded: 2009

Attack summary

Severity: critical — 500 GB of data has been published including confirmed medical data, criminal data, personal PII, and financial data belonging to the company's clients — constituting large-scale exfiltration of multiple categories of regulated and sensitive data.

The Genesis ransomware group claims to have exfiltrated approximately 500 GB of data from HostBooks, including client personal data, medical data, financial data, criminal data, legislation data, email archives, network user folders, and data from the company's file server. The post indicates data has been published/made available for download.

critical

Data the group says was taken

AI dossier — extracted from the leak post

Client data
Personal data
Medical data
Legislation data
Criminal data
Operational data
Financial data
Company file server data
Email archives
Network user folders

The group's post references roughly 1 proof file.

What the group claims

Founded in 2009, HostBooks is an accounting software provider. The company's software features cloud accounting, expense management, cloud storage, invoicing, reconciliations, inventory management, data import/export, financial reports and a client management portal.

The leak post

captured from the group's site

Founded in 2009, HostBooks is an accounting software provider. The company's software features cloud accounting, expense management, cloud storage, invoicing, reconciliations, inventory management, data import/export, financial reports and a client management portal.
For these lawyers, building a website is too complicated. The same goes for protecting their clients' data.

```
- 500 Gb of accessible data.
- Clients Data.
- Personal Data.
- Medical Data.
- Legislation Data.
- Criminal Data.
- Operational Data.
- Financial Data.
- Data from company fileserver. 
- Email archives.
- Folders of network users. 

```

[Download The List of Company Files](http://genesis6ixpb5mcy4kudybtw5op2wqlrkocfogbnenz3c647ibqixiad.onion/download/72daf8151f038f9399f8.txt)

Data the group says was taken

Clients Data
Personal Data
Medical Data
Legislation Data
Criminal Data
Operational Data
Financial Data
Data from company fileserver
Email archives
Folders of network users

Screenshot of the leak post

Sources

Leak posthttp://genesis6ixpb5mcy4kudybtw5op2wqlrkocfogbnenz3c647ibqixiad.onion/72daf8151f038f9399f8/

Source

Indexed 3 days 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.

Disclosure context

About genesis

Timeline of this disclosure

Other recent disclosures by genesis

Sector and geography

Status timeline

At a glance

About the victim

Attack summary

Data the group says was taken

What the group claims

The leak post

Data the group says was taken

Screenshot of the leak post

Sources

Source