“Sometimes the easiest way to penetrate a billion-dollar company is to get close to the person running it,” Eric O’Neill, a former FBI counterintelligence operative, told Fortune.

For O’Neill, protecting executives should include teaching them to recognize manipulation—and giving others a way to intervene when the boss won’t listen.

Huang stepped down Thursday as president, CEO, and a board member of Nvidia, No. 16 on the 2026 Fortune 500, amid scrutiny of his relationship with a woman suspected of spying for China. The company named chief financial officer Colette Kress interim CEO while its board searches for a permanent successor.

In a message to employees Sunday, Huang acknowledged being unfaithful to his wife and said he would cooperate with the board’s investigation. The New York Times reported that U.S. intelligence officials believed Alice Huang, a former executive at Singapore-based Megaspeed, had been recruited by China’s intelligence service. The Chinese government has denied the allegations.

Nvidia’s board said Sunday that it had no reason to believe company secrets or national security had been compromised, but that its independent investigation, led by a committee of independent directors, would examine all available information. The company has lost about $450 billion in market value since Huang’s admission.

How trust becomes a security risk

O’Neill, whose undercover work helped catch FBI spy Robert Hanssen, founded NeXasure AI and wrote Spies, Lies, and Cybercrime. He said an intelligence-gathering attempt often looks, at first, like an ordinary relationship.

He said an approach rarely begins with someone asking an executive to hand over company secrets. It may start at a conference, through a business introduction, over drinks, or even on a dating app. The operative finds common ground, builds trust, and makes the executive feel important.

Romance can speed things up. Using romantic or sexual interest to gain information, access, or leverage is known as “honey trapping,” a tactic far older than dating apps.

The warning signs can be subtle, O’Neill said: a relationship that moves unusually quickly, persistent questions about sensitive business matters, requests to meet influential colleagues, or encouragement to keep secrets. The goal may be information, influence over a business decision, or compromising material that could later be used for blackmail.

Those signs are harder to recognize when the person under scrutiny is someone the executive trusts.

“By the time a security professional raises concerns, the executive may already be emotionally invested and unwilling to listen,” O’Neill said.

CEOs have access to information others want, from intellectual property and strategic plans to government relationships. O’Neill argues their security training should teach them how someone might use a personal relationship to get closer to those assets.

Peter Warmka, a former CIA senior intelligence officer who now trains executives through his Counterintelligence Institute, told Fortune his sessions cover who might target a company, what they want, and how they approach employees and contractors. Senior executives are prime targets because of their access, he said, but their attitudes toward security can also leave them exposed.

“Unfortunately, they are also perceived as more vulnerable because many believe not all security measures imposed on lower-level employees also apply to them,” Warmka said.

Much of his training focuses on overseas travel, including the risks of electronic eavesdropping in hotel rooms and on the way to meetings, intelligence collection targeting their devices, and interpreters who may work for intelligence services.

Even with that preparation, recognizing an attempt to extract information can be difficult. “Well-trained operatives know how to elicit information without raising suspicion,” Warmka said.

How boards can intervene when the CEO won’t listen

When a CEO dismisses a warning, someone else needs a way to act.

Chief security officers, general counsel, and chief information security officers should have a confidential route to independent directors, O’Neill said. If the CEO will not cooperate, the board can bring in outside counsel and investigators to assess a credible threat and recommend protective measures. Where warranted, the company should involve federal authorities.

A romantic relationship alone does not prove espionage, O’Neill emphasized. Any investigation should be objective and discreet, balancing the executive’s privacy with the company’s security. That requires someone outside the relationship to assess the risk.

“No executive, regardless of wealth, reputation, or brilliance, should be the final authority on investigating a threat in which that executive may be personally compromised,” O’Neill said.