WASHINGTON, D.C. (NewsNation) — Job portals like LinkedIn and Indeed are popular among job-seekers and recruiters alike, but national security experts warn the platforms have become hunting grounds for foreign spies.

“They’re going after every sector in the U.S. economy,” said Mirriam-Grace MacIntyre, executive director of the National Counterintelligence and Security Center. “They’re looking for people who are in academia, who are in research and development, who are in the private sector.”.

The sheer scale of the espionage effort has been amplified by social media, which allows agents from countries like China to engage with tens of thousands of people online without ever meeting them.

“(Foreign adversaries) only need 1% to say yes,” said Alan Kohler, assistant director of the FBI’s Counterintelligence Division. “That’s the problem that we face on the counterintelligence side.”

Kohler’s job is to help protect America’s secrets, but sites like LinkedIn and Indeed have brought on new challenges for him and his team. Unlike previous decades where spies gathered intelligence in person, today enemies can gain direct access to targets thousands of miles away with a few clicks of a button.

In 2019, former CIA officer Kevin Mallory was sentenced to 20 years in prison for espionage after being contacted by a Chinese headhunter on LinkedIn. The interaction set off a chain of events that ultimately led to Mallory providing the Chinese with classified documents in exchange for thousands of dollars.

Despite Mallory’s case becoming one of the few that have come to light, he is far from the only person who’s been targeted.

NewsNation spoke to a man — working in the intelligence community — who believes he was the target of a Chinese recruiting effort. Due to the sensitive nature of his job, NewsNation agreed to conceal his identity.

After applying for a job on Indeed and agreeing to a Zoom interview, the man said the conversation started off normal but quickly took a turn.

“(The interviewer) said that at his consulting firm, they were looking for ‘non-open source information,'” he said.

That’s when it occurred to the interviewee that he may be talking to someone seeking classified information.

Since it’s cheap and low risk, foreign adversaries can use job sites to cast a wide net, targeting professionals in multiple industries ranging from defense contractors to biotechnology experts. In recent years, MacIntyre says they’ve diversified the fields they target for experts.

China isn’t the only country leveraging the power of the internet. MacIntyre said North Korea, Iran and the Russian government are also involved in this type of activity.

There are more than 120,000 open jobs on LinkedIn that require some level of security clearance which has made it difficult for law enforcement to crack down on the problem.

“I think we’re doing all we can do, we can certainly do better,” said Kohler.

For now, the national security agencies are focusing on generating awareness so people can be on the look out for suspicious activity.