Depending on why you hired an advisor — creating a financial plan versus managing your portfolio — sharing info like your Social Security number or account numbers might not be necessary. If you're sending account statements or tax returns, black out such personal information, said Matt Rodgers, head of product for E8 Security, a cybersecurity analytics firm.
Don't be afraid to question the need for such data. "Ask, 'Why do you need this? What are you going to use it for?'" he said.
Nor should you share your own login information for financial accounts, even if the advisor needs access, said O'Leary. Brokerages allow you to fill out paperwork granting an advisor access and specifying actions he or she can take on your behalf.
Secure data transmissions
"As much as can be kept off of email, the better," said Patterson.
Either party's email could be the target of an attack, multiplying the risk of sensitive personal information falling into the wrong hands, he said. Use a secure file-transfer service, or if the firm has one, a secure client-access portal.
Recognize phishing attempts
After a breach, attackers may pose as your financial institution or advisor, sending emails designed to trick you into revealing more financial information. Don't click on any links in emails urging you to log in, change your password, sign up for credit monitoring services or take some other action, said Roemer.
Instead, use channels of communication you know to be correct — calling the office directly, for example, or typing your financial institution's web address directly into a new browser window.
Set up communication protocols
Agree upfront with your advisor on how you'll handle any important communication or account instruction, said Rodgers. (He and his advisor, for example, have agreed that his advisor will email, asking Rodgers to call the office.) That kind of setup prevents an attacker with access to either party's email from gaining access to more financial information — or cash.
"Having email passwords cracked is a fairly common issue for all of us," he said. "We don't want to put our financial lives in jeopardy because we didn't make some common-sense decisions upfront."