Donald Trump frequently visits his resort at Mar-a-Lago in Florida's Palm Beach (AFP)

A Chinese woman who stirred fears of espionage when she entered President Donald Trump's Mar-a-Lago resort carrying multiple mobile phones and a malware-spiked thumb drive was found guilty of trespassing and lying in a Florida court Wednesday.

Zhang Yujing, 33, was arrested on March 30 at Mar-a-Lago in Palm Beach, Florida, where Trump was on one of his frequent visits, first presenting herself as a club member and saying she was headed to the pool -- despite not having a swimsuit.

The Shanghai native then claimed to be attending a non-existent Chinese-American friendship event. She carried two passports from the People's Republic of China, according to the US Secret Service which arrested her.

Secret Service agents at the scene found four cell phones, a laptop computer, an external hard drive and a thumb drive that "contained malicious software," according to charging documents.

She was charged with one count of making false statements to a federal officer and one count of entering a restricted building.

The case raised a scare amid a series of arrests of Chinese charged in the United States in recent years for alleged spying and commercial secrets theft.

A federal judge said at her arraignment that she seemed to be "up to something nefarious."

And shortly after the arrest, Secretary of State Mike Pompeo echoed that thought.

"I think this tells the American people the threat that China poses, the efforts that they're making here inside the United States not only against government officials, but more broadly," he said.

But she was not charged with espionage, and no evidence in the case was presented suggesting she was a spy.

Zhang, who despite her weak English insisted on acting as her own attorney in the trial, was found guilty on both counts, which could bring up to a five-year sentence and a $250,000 fine.

Zhang will be sentenced on November 22.