GMO Group urges customer system shutdowns following Onamae breach

# GMO Group urges customer system shutdowns following Onamae breach

https://gcdradar.vercel.app/incidents/gmo-group-urges-customer-system-shutdowns-following-onamae-b · AIR-2026-1602 · closed 2026-11-11

- Lane: Breaches & attacks
- Severity: 3 (Confirmed exploitation): Confirmed breach with severe operational response.
- Fix status: No fix needed
- First reported: 2026-10-27
- AI role: No AI role
- Products: Onamae Desktop Cloud

## Summary

Japan's GMO Group advised customers to disconnect systems and shut down computers after threat actors breached Onamae Desktop Cloud and threatened ransomware deployment. The incident caused precautionary operational disruptions.

## What to do

Disconnect affected systems from the internet and shut down computers as advised.

## Affected and fixed versions

- Affected: Onamae Desktop Cloud

## Latest updates

- 2026-10-28: GMO announces up to $1 million bounty for information on the Onamae breach (https://thehackernews.com/2026/10/japans-gmo-offers-1-million-bounty-to.html)
- 2026-10-27: Japan's GMO urges customers to shut down PCs amid ransomware threat (https://bleepingcomputer.com/news/security/japans-gmo-urges-customers-to-shut-down-pcs-amid-ransomware-threat)

## Sources

- 2026-10-27 BleepingComputer: Japan's GMO urges customers to shut down PCs amid ransomware threat https://bleepingcomputer.com/news/security/japans-gmo-urges-customers-to-shut-down-pcs-amid-ransomware-threat
- 2026-10-28 The Hacker News: Japan's GMO Offers $1 Million Bounty to Catch Hackers Behind FX Trading Cloud Breach https://thehackernews.com/2026/10/japans-gmo-offers-1-million-bounty-to.html
- 2026-10-28 techradar.com: Japanese internet giant GMO tells customers to unplug PCs after compromise https://techradar.com/pro/security/japanese-internet-giant-gmo-tells-customers-to-shut-down-and-disconnect-pcs-from-the-internet-following-data-breach-and-ransomware-threat

Verify against the vendor's advisory before changing production. Data CC BY-SA 4.0, https://gcdradar.vercel.app.