(NewsNation) — National security experts say foreign adversaries are using popular job sites like LinkedIn and Indeed to recruit spies and extract trade secrets from U.S. workers.

The new strategy has enabled intelligence agencies in countries like China to target thousands of people across a variety of industries, including those without access to classified government information.

“Today, we’re finding a situation where spies are going after all sorts of people that are not spies — average Americans,” said Mirriam-Grace MacIntyre, who is the executive director of the National Counterintelligence and Security Center (NCSC).

NewsNation spoke with MacIntyre and the assistant director for the FBI Counterintelligence Division, Alan Kohler, about the problem and what to look out for.

how big is the problem?

Identifying foreign agents online can be difficult, and bringing them to justice in the United States is even harder. That makes espionage via social media a fairly low-risk, low-cost proposition.

For that reason, it’s hard to know how often foreign adversaries are targeting Americans online. On its own, the Chinese government has been accused of going after tens of thousands of people worldwide, MacIntyre said.

If even a fraction of those people is duped, it could present a national security problem.

“(Foreign adversaries) only need 1% to say yes and then they’ve got a lot of people that they can talk to,” said Kohler.

which social media platforms are vulnerable?

Any social media site could be used to target individuals, but LinkedIn has become especially popular because it provides more professional data, MacIntyre said.

Federal authorities have already won convictions in multiple espionage cases that started on LinkedIn.

In 2019, former CIA officer Kevin Mallory was sentenced to 20 years in prison for conspiring to provide defense information to the Chinese government after being approached on the site. The initial interaction set off a chain of events which resulted in Mallory providing China with classified information in exchange for thousands of dollars.

In some cases, law enforcement has directly traced investigations to Chinese spies.

In 2017, a General Electric employee in Cincinnati was contacted on LinkedIn and invited to speak at a university in China. He ultimately took the trip, which the Chinese paid for. Once there, the employee was introduced to Yanjun Xu — a Chinese government intelligence officer — who pressured him to provide information on specific designs.

When the employee returned to the U.S., the FBI took over communications and eventually brought Xu into custody with help from Belgian authorities. Last November, Xu was sentenced to 20 years in prison.

who’s being targeted?

The victim’s profile can vary, depending on which country is doing the targeting. Professionals with some level of classified clearance from the U.S. government tend to be high priorities for foreign adversaries.

In other cases, foreign intelligence agencies will seek out people with specific expertise related to that country’s national interests.

“(China) puts out a five-year plan for critical technologies they want to collect on and if you have expertise in one of those technologies, you can bet that the Chinese intelligence apparatus is going to target you through your social media sites,” Kohler said.

That tactic — targeting private sector employees — is a relatively new phenomenon, MacIntyre said.

“20 years ago, espionage was really focused on getting access to government secrets,” she said. “But today, they’re going after every sector in the U.S. economy.”

MacIntyre said North Korea, Iran and the Russian government are also involved in this type of cyber-activity.

how does someone know if they’re being targeted?

There are a few things to look out for if you think you’re being targeted on social media.

• Urgency: Be cautious of anyone who connects on social media and makes it seem like they need information quickly.
• Do your research: Be skeptical of anyone who claims to be part of a company or think tank where there is little or no information available on the organization.
• Probing questions: Be wary of social media accounts that connect and follow up with a lot of questions pertaining to industry specifics.

“They’ll offer that person an opportunity that is difficult to turn down,” said MacIntyre. “For example — an all-expense paid trip, a high paying new job — all of these can be appealing to people and then once they get that person over into their country to agree to do that, those people are often put in compromising situations or are pressured to provide information that they shouldn’t provide.”

Both experts said it’s best to follow the old adage: if the offer sounds too good to be true, then it probably is.

what is the U.S. doing about it?

There are three ways the FBI is combating foreign interference on social media sites, Kohler said.

1. Traditional investigations, operations and intelligence
2. Engaging with social media companies to help them better understand the threats
3. Educating the public about the hazards and what to look out for

Unlike previous decades — where foreign adversaries collected intelligence in person — now enemies can target individuals from the safety of their own country, most of the time with just a few clicks of a button.

“It’s actually quite difficult to impact some of these actors overseas just because most of the countries where they operate from are not countries that are going to be very friendly towards FBI engagement,” Kohler pointed out.

That reality makes public awareness especially important, Kohler said.