Wave of Cyberattacks on Japanese Companies Prompts Government Call for Security Reviews

Japanese companies have spent the past few weeks under a cascade of cyberattacks, and the government has formally called on businesses to check their defenses. According to Bloomberg, the cause of the escalation is AI tools: they lower the barrier to entry for large-scale hacking. The original report does not disclose the exact number of affected organizations. But the form of the response says a lot. When a government addresses everyone at once, it is dealing with a systemic threat, not working through an individual incident.

What is known so far

There are few facts, and it is important not to speculate. Here is what can be stated:

• The attacks came as a series over several weeks, not as a single strike.
• The targets were Japanese companies. The original material does not name industries or specific companies.
• The government called for security reviews.
• The main risk factor cited is that AI makes large-scale hacking cheaper and easier.
• The original source contains no public data on intrusion methods, the scale of the damage, or who is behind the attacks.

Until details are disclosed, any claims about which model or tool the attackers used remain speculation.

Why AI changes the math of attacks

This topic has a particular significance for Japan. For years, the language worked as an informal defensive barrier: phishing emails in Japanese, especially in a business register with polite phrasing, gave away foreign authors through clumsy grammar. Language models remove that barrier. Well-written text in the right tone now takes seconds.

The effect then compounds. AI speeds up reconnaissance from open sources, helps write and rewrite malicious code for a specific environment, and automates vulnerability scanning. Attacking dozens of companies at once used to require an experienced team. Now a single operator can handle part of the routine work. This is an analytical assessment, not a summary of a report, but it is the logic by which the authorities explain their concern: what is growing is not the skill of the best hackers, but the number of people capable of carrying out an attack.

The Japanese context

The country has already faced painful incidents. In autumn 2025, ransomware halted operations at the brewing giant Asahi Group and the retailer Askul, and shipping and order problems became visible to consumers. It became clear then that the vulnerability of one company quickly turns into a supply chain disruption. In parallel, Tokyo is building a legal framework for active cyber defense, which gives the state more authority for preemptive countermeasures. The current call for reviews fits the same logic: the government does not expect businesses to protect themselves on their own.

What to check right now

If you are responsible for security at a company operating in Japan or working with Japanese partners, start with basic hygiene. This is what mass attacks most often break through.

• Perimeter: updates for VPNs, firewalls, and other edge equipment, and closing unnecessary external services.
• Access: multi-factor authentication wherever possible, and a review of privileged accounts.
• Contractors: a list of external organizations with access to your systems, and the permissions they hold.
• Backups: at least one offline copy, plus tested recovery, not just the fact that a backup exists.
• Segmentation: so that the compromise of one node does not open up the entire network.
• Employee training: phishing scenarios without grammatical errors, with plausible context and the names of colleagues.
• Incident response: a plan of action for an incident and drills in which it is actually rehearsed.

The main shift is that the signs of a "bad email" no longer work as a filter. Defense must rest on processes and technical barriers, not on the vigilance of individual employees.