Cases › security breach › LR-2026-0229
China-linked autonomous AI agent Artex used in cyberattacks on Japanese and South Korean firms
Whose AI: Artexsecurity breach
Severity major: Many third parties were affected: eight Japanese companies disclosed data leaks and South Korean financial institutions were also hit.
Earliest source we hold 2026-10-20
A security firm, the information security subsidiary of GMO Internet Group, investigated cyberattacks on Japanese firms and said the autonomous China-linked AI agent Artex was used in them.
Risk grouping: AI used to exploit
| Who caused it | A person or organisation “The GMO affiliate said its probe indicated that the autonomous AI agent Artex was employed in the cyberattacks against Japanese entities.” source |
|---|---|
| Intended or not | Intended “The GMO affiliate said its probe indicated that the autonomous AI agent Artex was employed in the cyberattacks against Japanese entities.” source |
| Before or after release | After release “The GMO affiliate said its probe indicated that the autonomous AI agent Artex was employed in the cyberattacks against Japanese entities.” source |
| The AI's part | Used as a tool “The GMO affiliate said its probe indicated that the autonomous AI agent Artex was employed in the cyberattacks against Japanese entities.” source |
The story
1 · What it was doingThe autonomous China-linked AI penetration tool Artex was used to attack Japanese firms, diagnosing system vulnerabilities; the GMO Internet Group security subsidiary investigated the attacks on retail, logistics and financial companies.
2 · What went wrongThe agent was used in unauthorized access to corporate systems, breaching those firms' security and leading to leaks of data.
3 · What it reached or didEight Japanese companies in retail, logistics and finance disclosed leaked data in September and October; South Korean financial institutions were also hit since late September.
4 · How it was caughtThe information security subsidiary of GMO Internet Group discovered six attacking devices targeting Japanese firms and identified Artex through its probe, publishing the finding on its blog.
5 · What was doneThe government said it is analyzing whether AI was maliciously used after hearing from damaged companies, and vowed to keep working to prevent cyberattacks.
Others like this
ARTEX autonomous penetration-testing agent used in attacks on South Korean financial institutions 2026-10-21
AI agent (ARTEX with Claude) used in cyberattacks targeting South Korean banks 2026-10-05
Show every field, with its source and grade
The AI system
Model
Artex
C one secondary source states it
What it was allowed to do
diagnosing system vulnerabilities
C one secondary source states it
How much it acted alone
it acted alone, unwatched
D inferred by us from the described behaviour, reason shown
How it was connected
agentic with tools
D inferred by us from the described behaviour, reason shown
What it was for
AI penetration tool for diagnosing system vulnerabilities
C one secondary source states it
What happened
Earliest source we hold
2026-10-20
A the date the source itself carries
Who caught it
an outside party
D inferred by us from the described behaviour, reason shown
Themes
AI agent misuse, cyberattack, Japan, data leak
D inferred by us from the described behaviour, reason shown
What went wrong
security breach
D inferred by us from the described behaviour, reason shown
AI agent
an AI agent acted
C one secondary source states it
Impact
Severity
major
D inferred by us from the described behaviour, reason shown
Who was affected
eight Japanese companies in retail, logistics and financial sectors; South Korean financial institutions
C one secondary source states it
Why this severity
Many third parties were affected: eight Japanese companies disclosed data leaks and South Korean financial institutions were also hit.
D inferred by us from the described behaviour, reason shown
Context
Industry
Retail Trade; Transportation and Warehousing; Finance and Insurance
C one secondary source states it
Country
Japan
C one secondary source states it
LR-2026-0229 · version 3 · published 2026-10-25 after automatic checks; not yet checked field by field by a person · changes to this case · JSON