China may be taking a page of the playbook used by Russia to meddle with the 2016 U.S. presidential election, targeting U.S. political action committees and various think tanks with spear-phishing emails.
The observation by FireEye, a private cybersecurity firm, still leaves key questions unanswered. What information China was able to get as a result of the attacks, if any, and how Beijing may intend to use any information are unclear.
"We have not yet directly observed subsequent attacker activity that would indicate the motivation or intent," FireEye told VOA via email.
But it adds to growing concerns that China is no longer content to steal information either to boost its military or the fortunes of Chinese technology companies, and may be ready to train its cyber capabilities on larger, strategic goals.
"They would like to see me lose an election because they've never been challenged like this," U.S. President Donald Trump alleged Wednesday, citing China's displeasure with tariffs on hundreds of billions of dollars' worth of Chinese products, part of an escalating trade war.
"We have evidence. It will come out," he added.
So far, Trump administration officials have been tight-lipped, promising more revelations in a speech next week in Washington by Vice President Mike Pence.
Still, U.S. intelligence officials have been hinting for months that China is poised to act more aggressively.
China is "asserting a whole-of-nation strategy in the cyber domain that is unprecedented in scale," U.S. Director of National Intelligence Dan Coats said at an event this past week, prior to the president's comments.
"China exploits our transparency and open society," Coats said. "China is also targeting U.S. state and local government and officials. It is trying to exploit any divisions between federal and local levels on policy."
FBI Deputy Director David Bowdich, speaking at the same event as Coats, went further, calling China the top counterintelligence threat.
"China is expanding its intrusions," Bowdich said. "We have folks throughout the country that are being approached."
There are also indications China has been testing out its ability to infiltrate the electoral systems of other countries, most notably targeting political organizations, politicians and journalists in Cambodia in the months leading up to that country's election this past July.
"This includes compromises of Cambodian government entities charged with overseeing the elections," FireEye said in a report, attributing the attacks to a group known as TEMP.Periscope, known for its focus on the maritime industry.
But not everyone is convinced China is ready to weaponize its cyber capabilities and unleash them on the U.S. election in November.
"So far, at least, they don't seem to have made the political decision, the political calculation, that they want to go in that direction, the same direction that the Russians have," Ned Price, a former CIA analyst and former spokesman for the National Security Council under President Barack Obama, told VOA.
China is thought to have hacked the presidential campaigns of both Obama and Republican Senator John McCain in 2008. But while the hackers took a significant number of files, it is not clear the information was "weaponized" in any way.
Price said what China has been doing still seems to be in the realm of "what we would expect of other strategic adversaries, collecting information for political advantage or economic gain."
"But obviously that's always one decision away," he added. "I unfortunately have no doubt that they have plenty of fodder and material that they could use."
For its part, China has rejected the accusations by Trump as "crazy talk," attributing his remarks to "campaign strategy."
"China has always adhered to the policy of noninterference in the internal affairs of other countries," Chinese Foreign Minister Wang Yi said Wednesday. "We don't accept any groundless accusations made against China."
'It employs cyberbullying'
But U.S. intelligence officials and defense officials have long argued the question is not whether China interferes but what types of tactics Beijing wants to bring to bear.
They also worry China is learning from Russia's efforts during the 2016 U.S. presidential election, combining cyber tools and attacks with other means to wield influence.
"It employs cyberbullying. It employs, in some cases, corruption," a senior Trump administration official told White House reporters following the president's public accusations.
"It employs propaganda, and things that appear to be more normal modes of interacting and studying information," the official added.
And not all of those tools are necessarily being deployed to influence campaigns in the near term.
'The long game'
"China plays the long game," National Security Agency Deputy Director George Barnes warned a security conference in Washington in June. "They're very thoughtful, methodical, strategic, and they're taking steps that may not be realized for 20 years, but they're taking them and they're bold about it."
It is an approach that has a growing number of officials and analysts warning that, in the end, China may be able to have a bigger impact than any meddling by Moscow.
"The real challenge, in the long run, is honestly China," said Jamie Fly, a senior fellow at the German Marshall Fund. "China can take all the tools the Russians deployed against us in 2016 and use them much more effectively."