South Korea and Japan Investigate Cyberattacks Amid AI Security Concerns

South Korean banks and Japanese companies are investigating cyberattacks as authorities examine whether AI tools helped attackers.

By News National Editorial Team

SEOUL/TOKYO, October 12, 2026: Banks and businesses in South Korea and Japan are strengthening cybersecurity measures following a wave of reported attacks that has raised concerns about how artificial intelligence may be helping cybercriminals. Investigations are continuing, and authorities have not established that AI was used in every incident.

Reuters reported on October 9 that nine South Korean banks and two large churches were investigating cyberattacks. Japanese companies, including Daiwa Securities, SoftBank and Lawson, were also among organisations affected by a recent increase in cyber incidents.

South Korean financial institutions investigate breaches

South Korean President Lee Jae Myung said earlier in October that recent attacks on banks appeared to involve AI tools. Reporting by the Financial Times said data at seven financial firms had been compromised, including customer information at several banks and savings institutions. Authorities were investigating the incidents and the methods used to access the affected systems.

Cybersecurity researchers and investigators have examined whether AI-assisted tools were used to identify software weaknesses or accelerate other parts of the attacks. Reuters reported that a cybersecurity firm assessed that AI assistance probably played a role in incidents linked to a suspected China-based attacker. That is a reported assessment, not a final judicial finding.

The exact method, extent of access and potential impact differ by incident. It would be inaccurate to describe every reported attack as an AI-driven breach or to assume that all affected organisations suffered the same type of data loss.

How AI may change cybercrime

Artificial intelligence can help automate certain technical and administrative tasks. In a criminal context, that may include analysing public information, generating convincing phishing messages, assisting with code or helping identify potential weaknesses in exposed systems.

These capabilities can reduce the time required for some activities, but AI does not automatically make an attack successful. Many intrusions still depend on familiar weaknesses such as unpatched software, stolen credentials, excessive permissions or inadequate monitoring.

For defenders, the challenge is to detect suspicious behaviour while distinguishing malicious automation from legitimate system activity. AI-based security products may help analyse large volumes of events, but they also require careful configuration and human oversight.

Japan faces a wider rise in cyber incidents

Reuters reported that Japanese companies including Daiwa Securities, SoftBank and Lawson had faced recent cyber incidents. The report described an environment in which businesses were racing to improve their defences as attacks became more frequent.

Separately, data cited in Reuters reporting indicated rising cyber incidents in South Korea. Figures from national reporting systems and private cybersecurity companies use different methods and definitions, so they should not be compared as if they measured precisely the same thing.

Nevertheless, the incidents have prompted concern among businesses that rely on digital services and handle large volumes of customer or financial information.

Regulators and companies respond

South Korea's financial authorities have called on institutions to review their security posture and improve their ability to detect and respond to attacks. Organisations can reduce exposure by enforcing multi-factor authentication, promptly applying security updates, limiting access to sensitive systems and monitoring unusual account activity.

Banks and technology companies should also test their incident-response plans, preserve logs and examine third-party connections. Employee training remains important because phishing and impersonation can provide attackers with access even when technical controls are in place.

What the developments mean internationally

The incidents in East Asia are relevant to organisations around the world, including Indian banks, fintech companies and online businesses. Attackers do not need advanced AI tools to exploit weak controls, but automation may make some techniques easier to repeat at scale.

The immediate priority is to establish what happened in each case, notify affected customers where required and address the weaknesses identified by investigators. As authorities release more findings, the precise role of AI and the scope of individual breaches may become clearer.

Sources:

• Reuters, October 9, 2026: https://www.reuters.com/legal/litigation/south-korea-japan-buffeted-by-hacks-ai-lowers-bar-cybercriminals-2026-10-09/

• Financial Times, reporting on South Korean financial-sector cyberattacks: https://www.ft.com/content/fb32e9f8-4bf7-44ad-983d-1a03f50f66f5