AI-Driven Cyberattacks Batter Japan, South Korea as Corporate Risk Mounts

Japan and South Korea are grappling with a surge of cyberattacks that cybersecurity experts say are being supercharged by artificial intelligence, exposing personal data of millions of customers and forcing regulators to demand sweeping security overhauls.

In Japan, the government has issued a nationwide cybersecurity warning after a string of breaches hit major corporations. Convenience store chain Lawson, securities firm Daiwa Securities, second-hand retailer BookOff, and car-sharing operator Times Car have all reported data leaks. Times Car alone exposed information linked to around 6.6 million customer accounts, according to multiple reports.

The Japanese government is now urging companies to treat cybersecurity as a core management issue. “We ask companies to treat cybersecurity as a core management issue, expand related investment, and put in place specialist staff and response units prepared for incidents,” the government said in a statement reported by Kyodo News.

Masaaki Taira, who heads AI policy for the ruling Liberal Democratic Party, described recent attacks as “saturation attacks” in which AI is used to automatically repeat assaults on a massive scale. “We need technical countermeasures that can automatically detect anomalies and block the spread of damage after an IT system is breached but before sensitive information is actually leaked outside,” he said, as reported by Seoul Economic Daily.

Japan’s Digital Transformation Minister Toshihiro Furukawa, cited by Indian news outlet India Today, warned that “cyberattacks are increasing in both quality and quantity, the methods are becoming more sophisticated, and they are having a tremendous impact on people's lives, and of course, causing significant disruption to business activities.” He added that leaked data can lead to “identity theft, fraudulent money transfers, and other scams.”

The scale of the problem is stark. Japan recorded more cybersecurity incidents in the first nine months of this year than in all of last year, according to data from TrendAI cited by Reuters. Incidents reached 86 in September, up about 18% from August and 37% from July. A separate study by Yomiuri and Trend Micro, reported by India Today, found Japan has already recorded more than 500 cyberattacks this year, putting it on course to set a new record.

South Korea is facing a parallel crisis. Nine banks and two mega-churches are investigating attacks that may have involved AI tools, according to government data. The country recorded 1,236 cyber incidents in the first half of this year, up 20% from a year earlier. While server hacking cases fell, reports of distributed denial-of-service (DDoS) attacks rose 56.7% and ransomware incidents surged 76.8%, Reuters reported, citing government data.

US cybersecurity firm CrowdStrike assessed that a suspected 26-year-old China-based attacker behind the South Korean bank incidents would probably not have been able to carry out the campaign without AI assistance, Reuters reported. The individual, whom CrowdStrike assessed was pursuing financial gain, used a Chinese-developed AI agent and Anthropic’s Claude Code. “While (the hacker’s) capabilities were not terribly sophisticated they were effective,” said Adam Meyers, CrowdStrike’s senior vice president of counter adversary operations, as quoted by Reuters.

Cybersecurity experts say AI is lowering the bar for criminals with limited technical skills. “AI doesn’t get tired… My view is that Japan is essentially being subjected to carpet bombing,” said Nobuo Miwa, president of Tokyo-based cybersecurity firm S&J Corp, in comments to Reuters. He said the rise suggests attackers have crossed a threshold in “effort, motivation and technical capability,” while AI has erased language and other barriers that once hindered foreign hackers.

AI-powered tools are also making it harder for defenders to detect suspicious behavior, said Choi Kyoungjin, director of the Center for AI, Data and Policy at Gachon University near Seoul, as reported by Reuters. “With general-purpose AI models, even ordinary users with malicious intent can ask the system to look for vulnerabilities and it will do much of that work for them,” he said.

Warnings about AI’s growing role in cybercrime are increasingly coming from the technology’s developers. Alphabet’s Google and Anthropic have both warned that AI-assisted attacks are becoming more common globally, Reuters reported. “At this point, we can assume that all threat actors are using AI in some capacity and their operations have benefited,” John Hultquist, the chief analyst at Google’s Threat Intelligence Group, said last month, as quoted by Reuters.

Although the breaches have not yet resulted in material financial losses, risks could increase if stolen data is used in phishing or “smishing” campaigns, Karen Wu, senior analyst at Fitch, wrote in a note cited by Reuters. “We expect the incidents to result in regulatory penalties, customer compensation costs, and a sector-wide increase in cybersecurity spending,” Wu said.

Regulators in both countries have begun responding. South Korea’s Financial Services Commission has directed financial industry associations, regulators and affected executives to complete a 12-point cybersecurity self-assessment, according to Reuters. In Japan, Digital Transformation Minister Furukawa convened a meeting of ministries and agencies following the recent attacks, and the National Cybersecurity Office plans to issue warnings to businesses.

S&J’s Miwa said he expected elevated levels of cyberattacks to persist. “The attackers have experienced a breakthrough that has rendered many of the old assumptions obsolete,” he said.