京成建設株式会社

Summary

Keisei Construction Co., Ltd. experienced an unauthorized access incident affecting its network infrastructure, prompting technical remediation guidance for users. The company advised verifying physical network connections, restarting routers and modems, and adjusting firewall or antivirus permissions to allow Chrome access. Instructions included reconfiguring proxy server settings via browser controls or disabling proxy use entirely for local networks if unintended. The response focused on restoring connectivity through device reboots and network configuration checks without detailing the incident's origin or broader operational impacts.

Motives

Detailed motive labels are available to members.

TTPs

Detailed technique labels are available to members.

Description

On or around April 1, 2022, Keisei Construction Co., Ltd. publicly reported an incident involving unauthorized access ("不正アクセス") to its systems, as indicated by a notice published on its corporate website. The company provided immediate technical guidance to users experiencing network disruptions, directing them to inspect physical network components such as cables and to reboot routers, modems, and other network devices. Instructions specifically addressed Chrome browser connectivity issues, advising users to verify firewall or antivirus permissions for the application and to re-add Chrome to allowed program lists if existing configurations failed. For proxy server users, the company recommended verifying proxy functionality with network administrators or disabling proxy settings entirely via Chrome's advanced settings menu under LAN configurations. These measures indicated active efforts to restore normal network operations following the unauthorized access event.

The incident impacted user access to network resources, necessitating client-side troubleshooting to reestablish connectivity. Keisei Construction's response focused on user-initiated remediation steps rather than detailing internal containment procedures or forensic findings. No specifics regarding the intrusion's origin, duration, data compromise, or operational consequences were disclosed in the published notice. The company's communication prioritized restoring basic network functionality through standardized browser and device resets without elaborating on broader organizational countermeasures or system modifications. Publicly confirmed impacts remained confined to access disruptions requiring the outlined technical adjustments by end users.

Sources

Sources available to members: 1 source.