You've locked your front door, installed an alarm, and trained your staff not to let strangers wander in. It is also important to consider the tradies who have keys to your digital systems. Your IT support company, your payroll provider, and your cloud storage service each have some level of access to your business. If they get hacked, you could be next.
This is the hidden problem with managed service provider security. Australian small businesses are increasingly reliant on external suppliers who connect to their systems, store their data, or manage their technology. Each relationship creates a potential entry point for attackers.
Why Attackers Love Targeting Suppliers
Breaking into a well-defended business directly takes effort. But if an attacker compromises one supplier who services many clients, they have hit the jackpot. One breach can lead to many victims.
The Latitude Financial breach in Australia exposed data on millions of people. The entry point was compromised credentials from a third party. The SolarWinds attack affected thousands of organisations globally through a single software update. Attackers are aware that suppliers are often easier targets with bigger payoffs.
For small businesses, this creates an uncomfortable reality. You might do everything right internally, but a supplier's weak password policy or unpatched server could still lead to your client data being stolen.
How hackers learn about your business
Sophisticated attackers research their targets. They learn which suppliers you use, what software runs your business, and how your staff communicate. This research helps them craft convincing phishing emails that reference real vendors and real services.
An email appearing to come from your actual IT provider, referencing your actual software, asking you to click a link to "verify your account" looks legitimate because it is based on real information. Your staff have seen genuine emails like this before, so they often have no reason to suspect the message is fake.
This is why AI-powered phishing attacks are becoming more dangerous. Attackers can automate the research phase, generating personalised attacks at scale.
Managed Service Provider Security: What Australian Businesses Should Ask
The Australian Cyber Security Centre provides guidance on managing security when working with managed service providers. You don't need to become a security expert, but you should be asking some basic questions.
Consider what access they actually need. Your IT provider probably needs admin access to your systems, but your email marketing platform doesn't need access to your financial records. Match access levels to actual requirements.
Find out how they protect their own systems. A managed service provider handling your data should have security practices at least as good as yours. Ask about their staff training, their backup procedures, and how they would notify you of a breach.
Know what happens to your data when the relationship ends. It is important to know if you can get it back or if they will delete it. These details matter more than most businesses realise until they're trying to switch providers.
Keeping your clients' data safe starts with your own house
If you're a professional services firm (accountant, lawyer, financial planner) handling sensitive client data, you have obligations under the Privacy Act. A breach originating from your supplier is still your problem. Your clients trusted you with their information.
Keeping your clients' data safe means understanding where their data goes. If you use cloud accounting software, that provider now holds your clients' financial information. If you use a document signing service, that provider processes sensitive contracts. Each supplier relationship extends your compliance responsibilities.
The same applies if you're an MSP yourself. International guidance from CISA makes clear that managed service providers are high-value targets precisely because of the access they hold to multiple client environments.
The Human Element: Where Supplier Attacks Often Start
Most supply chain breaches don't begin with sophisticated hacking. They start with phishing. Someone at your supplier clicks a bad link, enters their credentials on a fake login page, or opens a malicious attachment. Now attackers have a foothold.
Your staff face the same risks. An email appearing to come from your IT provider asking them to "update their password" might actually be an attacker who's researched your supplier relationships. Your helpful support team wants to be responsive. That same helpfulness makes them vulnerable to well-crafted requests.
This is where phishing simulation training pays off. When your staff have practised spotting fake emails (including ones that impersonate your real suppliers), they're less likely to fall for the real attacks.
Practical Steps You Can Take This Week
Make a list. Write down every external company that has access to your systems, data, or premises. Include software providers, IT support, cleaning companies with building access, and other contractors. Most businesses are surprised how long this list gets.
Check access levels. For each supplier, ask whether they still need the access they have. Former contractors still having active logins is more common than you might expect.
Review your contracts. Check whether your supplier agreements include terms about security requirements or breach notification, and consider adding these terms when contracts renew.
Train your people. Your staff are the last line of defence when phishing emails arrive that impersonate your suppliers. Regular, realistic training helps them recognise these attacks before clicking.
Building a Security-Aware Culture
You can't audit every supplier's security practices yourself. But you can build a team that questions unexpected requests, verifies unusual payment instructions through a second channel, and reports suspicious emails rather than just deleting them.
This doesn't require expensive consultants or complex technology. It requires consistent practice. Simulated phishing tests that mirror real supplier impersonation attempts teach your staff what to look for in a way that reading policies never will.
The goal isn't perfection. Someone will eventually click something they shouldn't. The goal is reducing how often it happens and ensuring people report incidents quickly when they do.
Start With Your Own Defences
You can't control your suppliers' security practices, but you can control how your team responds to attacks that use supplier relationships as cover. Regular phishing simulation creates muscle memory. When the real attack arrives disguised as a message from your IT provider, your staff will pause instead of clicking automatically.
You can see how your team would respond to a supplier impersonation attack by signing up for a free trial of Phishing Training Australia and sending yourself a test email. It takes about two minutes, and you'll immediately understand why this training matters.
