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Ransomware victim Business Services

Kumagai Gumi Group

Listed by Alphv on · organisation based in Japan

kumagaigumi.co.jp

Disclosed
Mar 1, 2024
Leak-site listing date
Threat group
Alphv
59 victims listed
Country
Japan
#11 most targeted
Sector
Business Services

ThreatAI analysis

Compiled from this incident record and the threat intelligence profile for Alphv. Figures and technique mappings are quoted from the source data, not inferred.

About the Alphv group

The operators of the ALPHV/BlackCat ransomware began their activity in December 2021, making posts on Dark Web forums to promote their affiliate program, offering other actors the opportunity to engage in a 'new type of ransomware family' developed from scratch using the Rust programming language. Some clear evidence indicates that the actors behind this new ransomware are not new to cybercrime, and there were links to other affiliate programs such as DarkSide, BlackMatter, and REvil. (After several attacks against large companies, these groups faced pressure and arrests, necessitating the termination of their operations). As a security measure, the operators of ALPHV implemented the requirement for the execution of the ransomware payload by providing an 'access token,' which is supplied by the owners of the Ransomware-as-a-Service to the affiliate. This token is added to the victim's ra Alphv has listed 731 victims since September 2021.

How Alphv is documented to operate

Valid Accounts T1078 Stealth Persistence

Adversaries may obtain and abuse credentials of existing accounts as a means of gaining Initial Access, Persistence, Privilege Escalation, or Defense Evasion. Compromised credentials may be used to bypass access controls placed on various resources on systems within the network and may even be used for persistent access to remote systems and externally available services, such as VPNs, Outlook Web Access, network devices, and remote desktop. Compromised credentials may also grant an adversary increased privilege to specific systems or access to restricted areas of the network.

Mitigations: Application Developer Guidance, User Training, Password Policies, User Account Management, Privileged Account Management, Multi-factor Authentication

MITRE ATT&CK reference
External Remote Services T1133 Persistence Initial Access

Adversaries may leverage external-facing remote services to initially access and/or persist within a network. Remote services such as VPNs, Citrix, and other access mechanisms allow users to connect to internal enterprise network resources from external locations. There are often remote service gateways that manage connections and credential authentication for these services. Services such as Windows Remote Management and VNC can also be used externally. Access to Valid Accounts to use the service is often a requirement, which could be obtained through credential pharming or by obtaining the credentials from users after compromising the enterprise network.

Mitigations: Limit Access to Resource Over Network, Restrict Web-Based Content, Network Segmentation, Multi-factor Authentication, Disable or Remove Feature or Program

MITRE ATT&CK reference
Exploit Public-Facing Application T1190 Initial Access

Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network. The weakness in the system can be a software bug, a temporary glitch, or a misconfiguration. Exploited applications are often websites/web servers, but can also include databases (like SQL), standard services (like SMB or SSH), network device administration and management protocols (like SNMP and Smart Install), and any other system with Internet-accessible open sockets. On ESXi infrastructure, adversaries may exploit exposed OpenSLP services; they may alternatively exploit exposed VMware vCenter servers.

Mitigations: Vulnerability Scanning, Limit Access to Resource Over Network, Filter Network Traffic, Network Segmentation, Privileged Account Management, Application Isolation and Sandboxing

MITRE ATT&CK reference
Scheduled Task/Job T1053 Execution Persistence

Adversaries may abuse task scheduling functionality to facilitate initial or recurring execution of malicious code. Utilities exist within all major operating systems to schedule programs or scripts to be executed at a specified date and time. A task can also be scheduled on a remote system, provided the proper authentication is met (ex: RPC and file and printer sharing in Windows environments). Scheduling a task on a remote system typically may require being a member of an admin or otherwise privileged group on the remote system. Adversaries may use task scheduling to execute programs at system startup or on a scheduled basis for persistence.

Mitigations: Operating System Configuration, User Account Management, Restrict File and Directory Permissions, Privileged Account Management, Audit

MITRE ATT&CK reference

MITRE ATT&CK techniques attributed to Alphv across its recorded activity, not a finding about how Kumagai Gumi Group was reached.

Incident analysis

Kumagai Gumi Group was listed by Alphv ransomware, a group with 59 victims recorded in this database. The listing appeared on the group's leak site on March 1, 2024.

Kumagai Gumi Group is based in Japan and operates in the Business Services sector. Japan ranks #11 worldwide for ransomware disclosures, with 294 victims in this database.

Sector context. Business services firms often have access to multiple client environments, making them high-value pivot points for ransomware operators seeking to maximise impact across multiple victim organisations.

Alphv typically follows a double extortion model: data is exfiltrated from the victim's systems before files are encrypted, so the victim faces two demands at once — pay to restore access, and pay to keep stolen data unpublished. The leak site, where this listing appeared, is the lever for the second demand.

Source. Public leak-site disclosures aggregated via the ransomware.live API. The disclosure date is when the listing was published, which can differ from the date of compromise. This site does not publish or link to stolen data. Last updated .

Frequently asked questions

Was Kumagai Gumi Group attacked by ransomware?

Yes. Kumagai Gumi Group was listed as a victim of the Alphv ransomware group on March 1, 2024. The organisation is based in Japan and operates in the Business Services sector. The disclosure appeared on the group's dark web leak site.

Which ransomware group attacked Kumagai Gumi Group?

Kumagai Gumi Group was attacked by Alphv ransomware. Alphv is one of the most active ransomware groups, having claimed 59 victims globally. The group typically employs a double-extortion model: encrypting the victim's files and threatening to publish stolen data.

When did the Kumagai Gumi Group ransomware attack occur?

The ransomware attack on Kumagai Gumi Group was disclosed on March 1, 2024. This date reflects when the victim was published on the threat group's leak site, which may differ from the actual date of initial compromise.

What data was stolen in the Kumagai Gumi Group ransomware attack?

The specific data stolen from Kumagai Gumi Group has not been independently verified by this platform. Ransomware groups typically exfiltrate data before encrypting systems and use the threat of publication to pressure victims. As a Business Services organisation, Kumagai Gumi Group likely held sensitive business data, client information, and operational records.

How can organisations protect against Alphv attacks?

To defend against Alphv and similar threat actors, organisations should: maintain regular offline backups tested for restoration; implement network segmentation to limit lateral movement; deploy multi-factor authentication on all remote access; use endpoint detection and response (EDR) tools; conduct regular phishing and security awareness training; and monitor threat intelligence feeds for indicators of compromise (IOCs) associated with active groups.