Science & Tech · Cybersecurity · 1 hr ago
Japan sees sharp rise in data leaks as experts warn of AI misuse
Japanese companies and local governments reported 600 cases of data-related damage by September’s end, more than 100 above the same period in 2024 and 2025.
A major case involved Times Car, a car-sharing service, whose system exposure affected about 6.6 million pieces of personal information, including driver’s license images.
JR East, Bookoff and Skyticket have also announced possible leaks involving millions of items of information.
Experts say attackers may be using AI to find system weaknesses faster and help carry out attacks.
A hacker said some attacks that once took two weeks could now be done in several dozen minutes with AI assistance.
The leaked information could be misused for identity fraud, including impersonation during bank account applications.
Security experts say they have seen traces that AI may be used in attacks, but the article does not identify a confirmed cause for each leak.
Japan’s reported cases are on pace to reach a three-year high, while companies and local governments face the challenge of defending against faster attacks.
Japan had 600 publicly reported cases of unauthorized access and other damage by the end of September 2026, more than 100 above the same period in either 2024 or 2025.
The Times Car leak exposed about 6.6 million pieces of personal information, including images of driver’s licenses.
Since October began, several companies have announced possible leaks affecting millions more items of information.
Experts say artificial intelligence may help attackers find vulnerabilities and carry out attacks faster, though the extent of its role is uncertain.
- Who
- Japanese companies and local governments have reported data leaks and other cyber damage. Experts say attackers may be misusing AI.
- What
- Reported cases of unauthorized access and other damage have risen. Several companies have disclosed large leaks or possible leaks.
- When
- By the end of September 2026, 600 cases had been publicly reported. Further leak announcements came in October.
- Where
- Japan.
- Why
- Experts point to possible AI misuse, including using AI to find system vulnerabilities and create malware. The sources do not establish that AI caused every reported incident.
This story does not have two clearly opposing sides.
White-hat hacker Takayuki Sugiura said AI-assisted vulnerability discovery had sped up.
Anthropic released its Claude Mythos model and restricted which organizations could use it amid concerns about misuse.
Japanese companies and local governments had publicly reported 600 cases of unauthorized access and other damage that year.
Times Car announced a leak exposing about 6.6 million pieces of personal information.
JR East, Bookoff Group Holdings and Adventure announced possible leaks affecting millions of items of information.
- Reported cases
- 600 by the end of September 2026
- Year-on-year comparison
- More than 100 above the same period in 2024 and 2025
- Times Car leak
- About 6.6 million pieces of personal information exposed
- JR East and Viewcard
- Up to about 6.09 million pieces of information may have leaked
- Bookoff Group Holdings
- Up to about 6.43 million items may have leaked
- Adventure, operator of Skyticket
- About 14.64 million items of information may have leaked
What people are saying
Since March, the speed of finding vulnerabilities using AI has increased.
The reality is that defenders are being forced onto the back foot.
Traces of AI-based attacks remained in past damage.
Attackers may be using AI more actively, such as creating malware through interactions with AI.