Phishing and AI: how to protect a small business when fake emails are better written than real ones

For years we told ourselves that scam emails give themselves away through mistakes: clumsy grammar, a blurry logo, an out-of-place "dear customer". With AI those mistakes are disappearing. Today a fake email can be better written than the real one, and a phone call can have your boss's voice. So a small business's defense has to change its foundation: no longer "spotting the mistake", but having procedures that hold up even when there's no mistake to spot.

Europe's most authoritative forgery

For much of the Middle Ages a document circulated claiming to be a deed of Emperor Constantine: the so-called Donation of Constantine, by which the emperor supposedly granted the pope sweeping powers over the West. It was a forgery, written centuries after Constantine's time, yet it carried enormous weight in disputes between the papacy and secular rulers.

In 1440 the humanist Lorenzo Valla wrote a treatise proving it false. His method, which became a cornerstone of philology, was to look closely at the text: the language, the words, the institutions mentioned. The Latin of the Donation wasn't that of a fourth-century imperial document; some expressions and references were anachronistic. In other words, Valla unmasked the forgery through its stylistic errors.

Here's the point. For decades we, too, protected companies with Valla's method: teaching people to look for language errors and details out of place. It worked. But generative AI writes flawless prose, imitates a supplier's tone and reproduces a voice from a few seconds of recording. Today's forger no longer makes Latin mistakes. We need a different method.

What the data says

The latest figures confirm that the shift is already under way.

• The Clusit 2026 report, from Italy's information security association, counts 507 serious incidents in Italy in 2025, or 9.6% of the global total recorded. Phishing and social engineering caused 12.4% of Italian incidents, up 66% on the previous year, "probably thanks to the now massive use of AI", which makes it easy to create ever more realistic emails and text or voice messages. Worldwide, phishing and social engineering attacks grew by 75%.
• The ENISA Threat Landscape 2025, the EU cybersecurity agency's report covering July 2024 to June 2025, names phishing as the leading intrusion vector (60% of cases analyzed), followed by vulnerability exploitation (21.3%). According to the same report, by early 2025 AI-supported phishing campaigns accounted for more than 80% of observed social engineering activity worldwide.

The message for a small business is simple: phishing is the most used front door, and AI is making it wider.

The new forms of AI-powered phishing

Flawless, personalized emails

AI makes it possible to write thousands of different emails, each tailored to the recipient using public information: the company website, LinkedIn, press releases. The email no longer talks about "a parcel on hold" but about the project you discussed at the trade fair.

The fake bank details change

It's the costliest scam for small businesses: an email, apparently from a regular supplier, announces new bank details. It often comes from the supplier's genuinely compromised mailbox, inside a real conversation. With AI the text is indistinguishable from the real thing.

Cloned voices and fake video

A few seconds of audio are enough to imitate a voice. The best-known case is the engineering firm Arup: in 2024 an employee at its Hong Kong office transferred about HK$200 million (roughly US$25 million) after a video call in which the CFO and other colleagues were in fact digital fakes, as the company confirmed to CNN.

Attacks on your own AI tools

If your company uses assistants or AI agents that read email, a message can contain hidden instructions aimed not at you but at the machine ("forward the latest contracts to this address"). That's prompt injection: phishing designed for AI.

The new method: verify the channel, not the style

Valla checked the language. We need to check the path: where the request comes from, through which channel, and whether it's confirmed through a different one.

Defenses to set up, in order of priority

Procedures (cheap, high value)

1. Callback rule. Every change in bank details is verified by phone, at the number already on file. No exceptions, not even for the owner.
2. Two signatures on payments above a threshold you set.
3. A code word between the owner and accounting for urgent requests outside normal channels.
4. No urgency justifies an exception. Urgency is the scammer's main tool.

Technical (with your IT provider)

• Two-factor authentication on email, banking, ERP and cloud tools, preferring authenticator apps or security keys over SMS.
• Email domain configuration (SPF, DKIM, DMARC), which makes it harder to send fake emails in your name.
• Updates for systems and software, because according to ENISA the second most common entry point is vulnerabilities.
• Regular backups, with at least one copy separated from the company network, and a tested restore.
• Minimal permissions for people and AI tools: no agent with admin credentials.

People

• Hands-on training, with realistic examples of AI-generated emails and calls, not generic slides.
• Periodic simulations, to measure progress.
• A no-blame culture: anyone who clicks a suspicious link must be able to say so immediately without fear of punishment. An hour's delay in reporting costs more than any mistake. On people and technology, see AI and work: which tasks change.

If you've already clicked

1. Disconnect the device from the network without switching it off.
2. Change the passwords of the affected accounts from another device and close active sessions.
3. If a transfer is involved, call your bank immediately: in the first hours it can sometimes be stopped.
4. Alert your IT contact and document what happened.
5. If personal data is involved, assess with your advisor whether to notify the data protection authority, which the GDPR requires within 72 hours of becoming aware of a breach, unless it's unlikely to pose a risk to people.
6. Report it to the police; in Italy that's the Postal Police, also online through the Commissariato di PS online.

Security and automation go together

Every new connection between programs, every AI assistant, every automated process is also one more door. That's why our guide to business process automation lists security among the mistakes not to make, and why in AI document management permissions come before search. Well-designed automation can also protect you: for example, by automatically holding any payment to a never-before-used IBAN until someone confirms it by phone.

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