Chinese hackers launched a massive attack on internet-connected devices in Finland in an attempt to sweep up audio and visual intelligence ahead of President Trump’s summit there with Russian President Vladimir Putin, according to a private cyber analysis released Thursday.

The attacks on Finnish internet-connected devices originating from ChinaNet, China’s largest internet backbone, began spiking July 12, just four days before Mr. Trump and Mr. Putin met in Helsinki, claimed the analysis by the Seattle-based cybersecurity firm F5.

While Finland generally endures a minor amount of hacking activity, the analysis noted, overall cyber attacks jumped about 2,800 percent during the days surrounding the Trump-Putin summit.

The revelations of Chinese cyber espionage emerged amid the escalating trade war between Washington and Beijing — friction that has caused stock prices to drop in China, whose currency, the renminbi, traded at it lowest point in a year against the U.S. dollar Thursday.

Chinese and U.S. officials continued to exchange barbs after last week’s announcement by the White House that plans were in place to apply tariffs on up to $200 billion worth of Chinese goods. Earlier this month, Washington and Beijing levied tit-for-tat tariffs on $34 billion on each other’s goods.

While Chinese leadership has described Washington’s latest threats as “totally unacceptable,” Trump administration officials have continued to demand China reform its hardline trade negotiating tactics and curtail the theft of American technology and intellectual property — a major campaign pledge of Mr. Trump.

Seeking to strengthen trade ties outside the West, Chinese President Xi Jinping on Thursday took his first trip abroad since starting his second five-year term in office after Beijing abolished presidential term limits, allowing him to rule infinitely.

Mr. Xi visited the United Arab Emirates just after news broke from the Persian Gulf country that its state-owned Abu Dhabi National Oil Company had awarded $1.6 billion in contracts to the China National Petroleum Company.

Meanwhile on Capitol Hill, members of the House Intelligence committee zeroed in Thursday on Beijing’s penchants for intellectual property theft and industrial espionage, taking testimony from some of America’s leading China-watchers.

Michael Brown, a former Symantec CEO and Pentagon adviser, testified to the committee about specific areas where the Chinese government appears to have already comprised U.S. national security.

“Chinese companies already own significant parts of the military supply chain,” said Mr. Brown, who added that Beijing has “designs of U.S. military equipment” and is closely monitoring U.S. military advances in the fields of artificial intelligence and quantum computing.

Michael Pillsbury, Director of the Center on Chinese Strategy at the Hudson Institute, offered excerpts from his book “The Hundred-Year Marathon” and explained the big-picture problem that has been bubbling ever since China re-entered the world economy in the 1970s.

U.S. eagerness to integrate China into international bodies, such as the World Trade Organization, mean that Washington, regardless of who was in charge, often overlooked Chinese misconduct, including the way it acquired foreign science and technology, Mr. Pillsbury said.

“From the Chinese point view,” he said, “it is only very recently that they have been called out for this type of conduct. That is one reason why we are going to have a very hard time stopping these practices.”