How to Prevent Phishing Attacks in Your Business

A finance officer receives an email that appears to be from your managing director. The tone is familiar, the request is urgent and the bank details look plausible. They pay the invoice before calling to check. This is how phishing succeeds: not through careless people, but by exploiting busy people, trusted relationships and ordinary business processes. Knowing how to prevent phishing attacks means putting practical checks around the moments when a convincing email could become a costly decision.

Phishing is no longer limited to poorly written emails asking for passwords. Criminals now impersonate suppliers, executives, Microsoft 365 notifications, delivery companies and government agencies. They also use text messages, phone calls and fake login pages designed to capture credentials. For Australian businesses, the risk can include fraudulent payments, business interruption, privacy breaches and access to customer information.

Why phishing is difficult to stop with training alone

Staff awareness matters, but it cannot be your only defence. A well-crafted phishing email may arrive when someone is managing a deadline, covering a colleague’s leave or working from a mobile between appointments. Attackers also use information available on company websites, social media and previous data breaches to make their messages more credible.

The aim is not to turn every employee into a cyber security specialist. It is to make suspicious requests easier to spot, safer to report and harder to act on without a second check. Good protection combines people, processes and technology.

How to prevent phishing attacks with layered controls

A layered approach recognises that no single tool or policy catches every threat. If one control fails, another should limit the damage.

Secure email before it reaches the inbox

Email filtering can block known malicious senders, dangerous attachments and suspicious links before staff see them. Modern email security tools also inspect messages for impersonation attempts, such as an external sender using the name of your director or a supplier.

Your domain should be configured with email authentication controls, commonly known as SPF, DKIM and DMARC. These controls help receiving email systems verify whether a message claiming to come from your domain is legitimate. They will not stop criminals impersonating every external supplier, but they significantly reduce the chance of someone spoofing your own business name.

It is worth reviewing these settings carefully. An overly strict configuration can affect legitimate mail, while a weak configuration provides little protection. Your IT provider should test, monitor and progressively tighten the policy rather than treating it as a set-and-forget task.

Require multi-factor authentication everywhere it counts

Stolen passwords remain one of the most common outcomes of phishing. Multi-factor authentication, or MFA, adds another proof of identity, such as an authenticator app prompt or security key. If an employee enters their password on a fake website, MFA can still prevent an attacker from signing in.

Not all MFA methods offer the same protection. App-based authentication or phishing-resistant security keys are generally stronger than text-message codes. Attackers can sometimes trick users into approving an unexpected prompt, so staff should know that an approval request they did not initiate is a warning sign, not an inconvenience to clear.

Apply MFA to email, cloud file storage, finance systems, remote access, password managers and administrator accounts as a priority. Where possible, use conditional access rules that challenge or block unusual sign-in attempts, such as access from an unfamiliar country or device.

Limit what a compromised account can do

Assume that, at some point, a password will be exposed. The next question is whether one compromised account can access everything.

Give people access only to the systems and information they need for their role. Separate everyday accounts from administrator accounts, and review access when people change roles or leave. Restrict automatic email forwarding to external addresses, as attackers frequently create forwarding rules to quietly monitor conversations after gaining access to an inbox.

Backups are also part of phishing resilience. A criminal who gains access through a phishing email may attempt ransomware or delete cloud data. Keep protected, tested backups and make sure your recovery process is understood before an incident occurs.

Build a payment verification process that people can follow

Technology will not prevent every fake invoice or changed bank detail request. Your accounts team needs a simple, documented process for confirming payment changes.

For example, require staff to verify new supplier bank details through a trusted phone number already held in your records, not the number included in the email. A second person should approve high-value or unusual payments. Requests from directors for urgent transfers should follow the same process. Seniority should never be an exception to a financial control.

This can feel slower than acting on an urgent email, but a two-minute call is far cheaper than trying to recover money sent to a criminal account. Make the process easy enough that staff will use it when the pressure is on.

Train for real decisions, not tick-box compliance

Effective phishing training uses examples your team is likely to encounter. A construction business may see fake subcontractor invoices. A professional services firm may face Microsoft 365 login lures or fraudulent document-sharing notices. A retailer may be targeted with delivery, payment terminal or customer refund scams.

Short, regular training is more useful than a once-a-year presentation. Show staff how to check the sender address, hover over links on a desktop, question unexpected attachment types and recognise urgency, secrecy or pressure as manipulation tactics. Just as importantly, explain what they should do next: report the message using the approved method, then delete it only after IT has assessed it.

Simulated phishing campaigns can help identify training gaps, but they need to be handled well. The purpose is to improve habits, not embarrass individuals. Share the lessons with the whole team and use results to adjust training or controls.

Watch for AI-enabled phishing without overreacting

AI makes it easier for criminals to produce polished, personalised messages at scale. The old warning sign of poor spelling is no longer reliable. Attackers can also use AI-generated voice clips to imitate a manager requesting an urgent payment, although a convincing voice alone should never override your normal approval process.

The answer is not to ban useful technology or treat every message as hostile. It is to strengthen verification. A request involving money, passwords, sensitive data or changes to access should be confirmed through a separate, trusted channel. If a caller claims to be your CEO, call them back using a known number or confirm through an established internal channel.

Businesses adopting AI tools should also set clear rules for what information employees can enter. Customer records, financial information and confidential documents should only be used in approved systems with appropriate access controls and data settings. Human review remains essential when an AI tool handles customer enquiries, processes documents or drafts communications.

What to do when someone clicks a phishing link

Speed matters, but blame does not help. If an employee clicks a link, enters a password or opens a suspicious attachment, ask them to report it immediately. They should not wait to see whether anything happens.

Your IT team should then contain the risk. This may include resetting passwords, revoking active sessions, checking sign-in logs, removing malicious inbox rules, scanning the device and reviewing whether other accounts or files were accessed. If payment details were involved, contact the bank promptly and preserve the relevant emails and transaction information.

For a suspected privacy breach, assess what information may have been exposed and whether notification obligations apply. The right response depends on the facts, so having an incident response plan and clear contact points saves valuable time.

Make phishing protection part of everyday IT management

Phishing prevention works best when it is maintained, not launched once and forgotten. Review email security reports, failed sign-in attempts, privileged access, forwarding rules and staff training outcomes regularly. Update processes after a near miss, particularly if someone was almost convinced by a new type of scam.

For many small and mid-sized businesses, this is where managed IT support adds practical value. We can keep security settings current, monitor for suspicious activity and help your team make sensible decisions without adding unnecessary complexity. OzeIT takes the same approach to security as day-to-day IT: reduce the noise, address the real risks and give people a clear path when something does not look right.

The most useful next step is to test one everyday scenario this week. Send a mock changed-bank-details request through your current process, or ask how a staff member would report a suspicious Microsoft 365 email. The answer will show you where a small improvement could prevent a much larger problem.