Data Security in the Family Office: The Softest Target, and What to Do About It

A family can spend years building a structure that is discreet and well protected on paper, then lose that discretion in a single afternoon. Not to a sophisticated adversary, but because an assistant clicked a link, or a provider three contracts away got breached, and everything the structure was built to keep quiet, who owns what, through which entities, banked where, is suddenly a folder for sale on a forum. I have watched families spend fortunes on the legal architecture of privacy and almost nothing on the digital version of it. This piece is about closing that gap, plainly and concretely.

The numbers, plainly

Start with the environment, because it has changed. In the first quarter of 2026 France became the second most breached country in the world, with 23.5 million accounts compromised in three months, roughly three every second, on Surfshark's tally. Since January, independent trackers count more than 250 million records exposed across some 300 French services, and the casualties were not obscure: the national identity card agency, medical software used by thousands of practices, the national statistics office. None of this targeted wealthy families specifically. It does not need to. It means the digital ground everyone stands on, including every family office, is leaking constantly.

Now the sector itself, and the direction matters more than any single number. The most recent industry survey, run by AlTi Tiedemann Global with Campden Wealth in 2025, found that 60 percent of family offices have experienced at least one cyberattack, phishing first among them, and that 70 percent now rank cybersecurity as their top operational risk. A year earlier, Deloitte's deeper audit of 354 single family offices managing a combined 708 billion dollars had put the attacked share at 43 percent, 62 percent above one billion dollars of assets, with half of the victims hit three times or more and phishing present in 93 percent of attacks. The line points one way. What has not kept pace is the quality of the defence. When Deloitte examined the plans rather than the claims, 31 percent of offices had no incident response plan at all, only 26 percent could call theirs robust, barely more than half trained their staff, and 63 percent carried no cyber insurance. Offices increasingly say the right things; the audited reality is thinner. The attacks are routine. The preparation is not.

Why the softest target

The reason is structural, and it is the same reason a family office exists in the first place. It concentrates. In one small organisation sit the identities and passports of every family member, the account details, the ownership structures, the trust deeds, the passwords, the travel plans, the whole map of the family's wealth and life. A bank holds a slice of that picture and defends it with a security department. A family office holds all of it and defends it, typically, with a handful of people, personal devices, shared inboxes and goodwill. Criminals read this correctly: maximum value, minimum resistance. That is what a soft target is.

Where it actually comes in

Forget the image of someone breaking through a firewall. Attacks on family offices come through people and relationships. Phishing and business email compromise lead by a distance: a plausible email, a fake invoice, a request that looks like it comes from the principal. Stolen or reused passwords open doors quietly. Vendors and outside providers, the accountants, the IT contractor, the concierge service, extend the office's perimeter far beyond its walls, and a breach at any of them is a breach of the family. Personal devices and family members, especially the younger generation and household staff, carry office data outside every control. And the fastest growing threat, on Deloitte's reading, is deepfake impersonation: a cloned voice of the principal instructing a transfer. The wider data points the same way: Verizon's 2026 investigations report, built on more than twenty-two thousand confirmed breaches, finds ransomware in nearly half of them and third-party involvement rising sharply. Every one of these runs through the human layer, which is why the human layer is where the work is.

A governance question, not an IT ticket

Here is the point I most want to land. In a family office, data security is not the IT department's problem, because there usually is no IT department. When something is nobody's mandate, it is handled casually, delegated to whoever seems technical, and revisited only after an incident. The offices that stay out of trouble treat it the way they treat tax and succession: as a standing governance matter, with a named owner at principal level, a line on every board or family council agenda, and an annual review taken as seriously as a tax position. Discretion is an asset. Like every asset, it needs someone accountable for it.

The basics that stop most of it

The good news is that most of the threat yields to a short list of unglamorous measures. Multi-factor authentication on every account, no exceptions, including the principal's. A password manager for the office and the family, so nothing is reused and nothing lives in a notebook or a spreadsheet. Payment discipline above all: two people to approve any transfer, and a callback on a known number to verify any new or changed payment instruction, because no email, however convincing, should ever move money on its own. Regular phishing training for everyone who touches the office, explicitly including family members and assistants, since they are the ones addressed by name. And managed, updated devices, with the family's own phones and laptops inside the policy rather than outside it. None of this is expensive. All of it is a matter of deciding.

The layer a serious office adds

Beyond the basics, a well governed office adds a second layer. Map the data: know precisely what sensitive information the office holds, where it sits and who can reach it, then cut access back to what each person actually needs. Vet the vendors: every provider that touches family data should be asked about its own security, bound contractually to notify you of a breach, and reviewed yearly, because the outside provider is part of your perimeter whether you like it or not. Move sensitive documents off email attachments and into encrypted channels. Keep backups that are tested by actually restoring them. Write an incident response plan, one page is enough, that says who calls whom, in what order, on the afternoon it happens, and rehearse it once a year the way you would a fire drill. Commission an independent test of the office's defences annually. And carry cyber insurance sized to the office, after reading what it excludes.

What good looks like

In practice, the offices that handle this well share a rhythm rather than a budget. One named owner. A short standing item on every governance agenda. Once a year: training refreshed, backups restored as a test, the response plan rehearsed, the vendors reviewed, an outside party invited to try to get in. And a principal who can answer three questions without hesitation: who owns our security, when did we last rehearse an incident, and what exactly would we do at six on a Friday evening when a payment demand arrives from a compromised counterparty. If those answers come slowly, that is the finding.

The uncomfortable truth in the numbers above is that the families most exposed are often the ones that most prize discretion, because they assumed discretion was a legal product. It is not. It is a legal product and an operational habit, and the operational half can be lost in one afternoon and cannot be bought back. The structures deserve the years families spend on them. The data deserves, at minimum, a seat at the same table.