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cytomx.com

Claimed by Dispossessor · listed 2 years ago

27m
Age
since listed · data leaked

Status timeline

  1. ListedApr 19, 2024
  2. Data leakeddate unknown

At a glance

Group
Dispossessor
Status
Data leaked
Country
United States
Sector
Healthcare
Listed on leak site
Apr 19, 2024

About the victim

AI dossier — public-source company profile

CytomX Therapeutics is a clinical-stage biopharmaceutical company focused on developing Probody therapeutics for cancer treatment. The company specializes in antibody-drug conjugates (ADCs) and has multiple programs in clinical trials, with a lead candidate targeting colon cancer. CytomX is publicly traded and operates as an innovative oncology-focused drug developer.

Industry
Biopharmaceutical & Oncology

Attack summary

Severity: medium — Confirmed data publication by ransomware group targeting a publicly traded biopharmaceutical company likely holding sensitive R&D, financial, and operational data. However, no specific proof files, data inventory, or operational impact details are provided in the leak post excerpt.

The ransomware group Dispossessor claims to have breached CytomX.com and published data. No specific details about the scope of exfiltration, encryption, or data types are stated in the available leak post excerpt.

medium

What the group claims

cytomx.com

Sources

Source

Indexed 2 years 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 Dispossessor

Dispossessor is a recently emerged ransomware group that began operations in April 2024, primarily motivated by financial gain through extortion campaigns targeting organizations across multiple sectors. The group's country of origin and potential affiliations with other ransomware operations remain unclear based on publicly available intelligence, and there is insufficient documented evidence to confirm whether they operate as a Ransomware-as-a-Service model or as an independent entity. Given the group's recent emergence, detailed technical analysis of their attack methodology, specific initial access vectors, encryption techniques, and data exfiltration practices have not been extensively documented by major cybersecurity firms or law enforcement agencies, though their targeting patterns suggest they employ typical ransomware deployment strategies against business services, healthcare, technology, financial services, and manufacturing sectors. The group has reportedly compromised 344 victims since their emergence, with primary targeting focus on organizations in the United States, Canada, France, the United Kingdom, and India, indicating a preference for English-speaking and Western European targets. As of current reporting, Dispossessor appears to remain active with no documented law enforcement disruption actions or confirmed rebranding activities, though the limited timeframe since their emergence in April 2024 means their operational longevity and persistence remain to be determined. The group has been linked to 344 public disclosures across our corpus. First observed on a leak site on April 19, 2024; most recent post August 11, 2024. The operation is currently inactive.

Timeline of this disclosure

  • April 19, 2024cytomx.com listed by Dispossessoron the group's public leak site

Other recent disclosures by Dispossessor

Dispossessor has been linked to 344 public victims on Darkfield. A sample of the most recent:

See the full Dispossessor dossier →

Sector and geography

This disclosure adds to ransomware activity in the Healthcare sector, which has 2,600 disclosures indexed across all operators we track. Geographically, cytomx.com is reported in United States, a country with 11,033 ransomware disclosures in our corpus.

If your organisation is affected

A listing by Dispossessor means cytomx.com 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 Dispossessor'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.