Disclosure context

About Avoslocker

**Overview**: AvosLocker is a financially motivated ransomware group that emerged in June 2021, operating as both a Ransomware-as-a-Service (RaaS) platform and conducting direct attacks against organizations worldwide. The group has demonstrated sophisticated capabilities and has targeted over 70 victims across multiple critical sectors. **Origin & Affiliation**: While the exact country of origin remains unclear, AvosLocker operates as a RaaS model, recruiting affiliates to conduct attacks using their ransomware payload and infrastructure. The group has shown no clear ties to state-sponsored activities, appearing to be purely profit-driven cybercriminals. **Attack Methodology**: AvosLocker typically gains initial access through compromised Remote Desktop Protocol (RDP) credentials, VPN vulnerabilities, and phishing campaigns, subsequently deploying tools like Cobalt Strike for lateral movement and persistence. The group employs double extortion tactics, stealing sensitive data before encrypting systems and threatening to publish the information on their leak site if ransom demands are not met. Their ransomware uses strong encryption algorithms and includes capabilities to terminate security processes and delete shadow copies to prevent recovery. **Notable Campaigns**: The group has particularly targeted critical infrastructure sectors including education, manufacturing, finance, healthcare, and transportation, with significant attacks reported against organizations in the United States, Germany, Singapore, Canada, and France. CISA and FBI have issued joint advisories warning about AvosLocker's targeting of critical infrastructure, highlighting the group's impact on essential services. **Current Status**: As of recent threat intelligence reporting, AvosLocker remains active, continuing to recruit affiliates and conduct ransomware operations against organizations globally. The group has been linked to 70 public disclosures across our corpus. First observed on a leak site on June 13, 2021; most recent post February 11, 2023. The operation is currently inactive.

Also tracked as: Avos.

Timeline of this disclosure

December 26, 2022Chimbusco listed by Avoslockeron the group's public leak site

Sector and geography

This disclosure adds to ransomware activity in the Energy & Utilities sector, which has 6 disclosures indexed across all operators we track. Geographically, Chimbusco is reported in China, a country with 29 ransomware disclosures in our corpus.

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

China Marine Bunker (PetroTrans) Co., Ltd. (CHIMBUSCO)

listed as Chimbusco · Claimed by Avoslocker · listed 3 years ago

41m

Age

since listed · data leaked

Status timeline

Listed
Dec 26, 2022
Data leaked

At a glance

Group: Avoslocker
Status: Data leaked
Country: China
Sector: Energy & Utilities
Listed on leak site: Dec 26, 2022

About the victim

AI dossier — public-source company profile

CHIMBUSCO (China Marine Bunker Co.) is a Chinese state-affiliated enterprise established in 1972, jointly owned by PetroChina and COSCO Group. The company specialises in marine fuel supply including bunker oil, marine lubricants, and fresh water, as well as the trading, blending, transportation, and storage of oil products. It operates across more than 50 major ports and 30 branch offices throughout China, supported by a fleet of over 100 barges.

Industry: Marine Fuel Supply & Oil Products Trading
Founded: 1972

Attack summary

Severity: high — CHIMBUSCO is a significant state-affiliated Chinese energy and logistics enterprise with ties to PetroChina and COSCO Group; data has been confirmed published by the threat actor, indicating successful exfiltration from a strategically important infrastructure-linked company, though the specific data types and scale are not fully enumerated in the post.

Avoslocker claims to have compromised CHIMBUSCO and has published data ('data_published' status), indicating confirmed exfiltration of company data. The specific volume and nature of exfiltrated data are not detailed in the leak post.

high

Data the group says was taken

AI dossier — extracted from the leak post

Company operational data
Internal business documents

What the group claims

Established in 1972, CHIMBUSCO has since reformed with two major shareholders namely, PetroChina and COSCO Group engaging in marine fuel supply of bunker oil, marine lubricants and fresh water as well as trading, blending, transportation and storage of oil products. CHIMBUSCO operates over 50 major ports and 30 branch offices in China, with an operational fleet of over 100 barges.

Source

Indexed 3 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.