Large Balances, Small Teams: How Family Offices Get Attacked and Which Controls Hold

What makes a family office attractive

Ask what an attacker wants from a target and a family office answers almost every item.

The first is the payout. One successful fraud here can be worth as much as a hit on a mid-sized financial institution, and there is no institutional security department standing in the way.

The second is staffing. An office of five people probably has no IT employee and certainly no security lead. Often one person both chooses the software and releases the wires.

The third is temperament. Family offices hire for loyalty and discretion. Those are good traits, and they are also the ones a social engineer is trained to lean on.

The fourth is how much is already known. A principal’s travel, charitable giving, business interests, and family ties can usually be researched in an afternoon. All of it helps an attacker write a message that sounds like it belongs.

The fifth gets the least attention: there is no edge to defend. The work spills into homes, household staff, personal phones, and private travel, well beyond anything a firewall in an office suite covers. Attackers rarely go after the best-defended system first. They go after mail, passwords, and old access that everyone forgot was still live.

Eight places the exposure turns up

1. Fraudulent payment requests by email

This is the attack that drains accounts. Someone takes over or imitates a mailbox belonging to a principal, an attorney, an advisor, or a known vendor, then asks for a transfer and says it cannot wait. Because a family office routinely sends large amounts on short notice, the fake request looks like any other Tuesday. The FBI’s Internet Crime Complaint Center counted $3.05 billion in reported BEC losses for 2025, which makes it one of the most expensive categories the bureau tracks. That figure covers only what victims reported.

Typical versions:

• An invoice from a vendor you know, with the right name and logo and a different bank account.
• Revised escrow instructions ahead of a property closing, sent from an attorney’s account that has been taken over.
• An investment wire marked urgent that seems to come from the head of the family.

The people behind these are in no hurry. They may read a mailbox for weeks, learning how the office writes and how it pays, until a genuine transaction comes along. Then the false instructions arrive at the one moment they will look expected.

2. Phishing written for one office

Mass phishing is usually obvious. A message composed for your office in particular is much harder to catch. The writer draws on social media, public records, data-broker listings, and old breach dumps, and mentions actual people, actual transactions, and actual events. Controllers and executive assistants receive most of these, since they hold the access and release the payments.

3. Vendors and outside advisors

A family office depends on a long list of outsiders: banks, wealth managers, accountants, law firms, property managers, staffing agencies, art advisors, yacht crews. Each is a possible way in. A vendor whose mailbox has been compromised, and whose messages your staff already trust, is a well-worn route. It is often identified only after the funds have left. Verizon’s 2025 report found that the share of breaches involving a third party doubled in a year, to roughly 30%. Deloitte, meanwhile, found that 68% of family offices have no formal process for vetting vendors. Those two numbers do not sit well together.

4. People on the inside

Insiders are a risk whether they mean harm or simply make a mistake. Personal assistants, household staff, and employees on their way out tend to have wide access. Small offices are usually thin on background checks, separation of duties, and offboarding routine, so a login keeps working long after the job it was issued for has ended.

5. Ransomware and the threat of publication

Consider what a family office keeps on file: tax returns, trust documents, estate plans, prenuptial agreements, medical records, the private workings of a family. That is ideal extortion material. More and more, the demand is less about unlocking files and more about keeping them off the internet. Verizon’s 2025 Data Breach Investigations Report found ransomware in 44% of breaches, a sharp rise on the prior year, and most of these attacks now copy the data out before encrypting anything. A family that prizes privacy above nearly everything else feels that pressure most. Paying does not solve it, because a criminal’s promise is not something you can enforce.

6. An office without a building

Few family offices operate out of a single secured location. The work gets done at a residence, at a second home, in the air, on a personal phone, and on a laptop that also carries the principal’s private email. A device might release a wire one morning and book a vacation and check personal accounts the next.

The overlap is where the trouble lies. If office and personal life share devices, logins, and connections, then a problem that begins on the personal side arrives a single click away from the accounts that move money. Many offices look after the part they call “the office” fairly well. Few have marked a boundary around everything else the work passes through.

7. Digital information with physical consequences

A wealthy family cannot treat cyber risk and physical risk as separate subjects. Staff schedules, alarm-system access, itineraries, and where the children are on a given day are all stored as data somewhere. Flight tracking, property records, and photos with location tags can support a burglary, or something considerably worse.

8. The public record

A great deal about a family can be obtained legally: home addresses, property records, court filings, political donations, who is related to whom. Attackers use it to construct a believable pretext. They also use it to answer the “security questions” meant to guard your accounts. The rules here vary by jurisdiction and keep moving. At the federal level, the Consumer Financial Protection Bureau withdrew its proposed data-broker rule in May 2025. California went the other way with its Delete Act: since January 2026 residents have been able to submit one deletion request through the state’s DROP platform, and registered data brokers must begin honoring those requests on August 1, 2026. That helps. It is still a patchwork, and a family cannot depend on it alone.

The controls that hold

You do not need a global bank’s budget for any of this. You need a short list of controls that somebody is responsible for and that are kept up to date. This is the order we would take them in.

Name an owner

Security needs one accountable person, even when an outside firm does the work. The gap we run into most often is not an absent product. It is that no one is looking at the whole, so small things go unattended: a restore that has never been tried, a former vendor’s login that still works, a shared mailbox no one reads. Settle ownership first. After that, commission an independent risk assessment, so that decisions rest on what is exposed in fact and not on what someone believes is fine.

Wire controls, without exceptions

• Confirm by a second channel. Every wire and every change to bank details gets a phone call to a number that was on file beforehand. The number in the email does not count.
• Two approvers for anything over a threshold you set.
• A waiting period before paying a new payee or acting on changed instructions.
• A written callback procedure, rehearsed often enough that nobody has to think about it.

Identity

• MFA on every system, including email, banking, accounting, and cloud storage. Where the stakes are high, use an authenticator app or a hardware key in place of SMS.
• A password manager, so that no password is used twice.
• Access limited to what each role requires.
• Accounts closed on the day a person leaves.

Email and devices

• Email filtering that goes beyond spam and includes anti-impersonation.
• SPF, DKIM, and DMARC, so that outsiders cannot send mail that appears to come from your domain.
• Managed endpoint detection on any device that connects to office systems.
• Prompt patching, and removal of software the maker no longer supports.

A boundary between personal and office

• Principals and key staff get managed, hardened devices for office and financial work. Those stay apart from the phones and laptops used for the rest of life.
• Office email, accounts, and files stay off personal devices. Personal accounts stay off office devices.
• When work is done away from a managed office, route office traffic over a trusted, encrypted connection, so it does not rely on whichever network the principal has joined that day.
• Split the networks. Office systems should not travel alongside guest Wi-Fi and personal devices.

Vendors, treated as the access points they are

• Review a vendor’s security before granting access or sharing data.
• Write security requirements into the contract.
• Restrict what each vendor can reach, and monitor it.
• Regard any vendor email that changes payment details as suspect until a phone call confirms it.

Training for the people who get targeted

• Awareness training matched to each role. Include the principals, who draw the most attacks and frequently get the least training.
• Simulated phishing.
• Training for assistants and household staff, who are common entry points.
• An office where a person who questions a strange request, including one from the boss, is thanked for it and never scolded.

A plan made in advance

• A written incident response plan with actual names and escalation paths.
• Offline backups of critical records, with restores tested.
• An incident response firm and legal counsel chosen before anything goes wrong.
• Exact knowledge of your bank’s fraud-reporting window. When a wire is fraudulent, recovery is decided in hours.

A smaller public footprint

• Review what can be found publicly about the family.
• Use data-broker removal services. California residents can also file the state’s new DROP deletion request.
• Talk with family members about social media, location sharing, and how much they post.
• Where possible, arrange property ownership and public filings so that less is attributed to individuals by name.

Younger family members count too

Many offices are passing wealth to a generation that grew up online and has the footprint to show for it. Bring them into the training and the controls. One person’s personal device or social feed can expose the entire enterprise.

Cyber insurance, briefly

A properly written policy can pay for incident response, wire fraud losses, and extortion. Insurers have also started making baseline controls a condition of coverage. In 2025–2026, underwriters commonly ask for enforced MFA on email and remote access, endpoint detection on every device, and immutable backups along with evidence that a restore has been tested. Without that evidence, they decline to bind or offer a much thinner policy. So a good policy does two jobs. It is a financial backstop, and it gives the office a firm reason to finish the basics.

How Defendrs approaches it

We do not open with scare stories, and we do not open with a product list. Owning software and being secure are different conditions. An office can have a firewall, an antivirus license, and several “secure” portals and still have nobody responsible for how they fit together. With family offices we work the way we work with every client: find out what is exposed, secure what matters most, and keep the program maintained. In practice that means tightening the path a wire takes to approval, hardening identity across both office and personal accounts, and bringing the standing access of advisors and vendors under control. We do it discreetly, and we explain it in terms you can pass along to the family or the board.

A control that was configured once and never revisited slowly stops working. The measures described here turn away the large majority of real attacks, on the condition that someone updates them as the family, the office, and the vendor list change.

This is a business that runs on trust, and it should. The safeguard is a habit of confirming, and for anything involving money the confirmation is a phone call.

Unsure what is exposed? Start here.

The exposure check is a short set of questions covering email, devices, vendors, backups, and access. An attacker has likely worked through the same questions about your office already. It takes about three minutes.

→ Check your family office’s exposure · Book a consultation