At his Labor Day speech President Trump mentioned “china sent the plague to us. And other viruses from china over the years, swine flu, others you never heard of.”

Could he be pointing to the Clinton Server? Or other servers / company hacks?

From:

https://www.washingtonexaminer.com/news/chinese-company-hacked-hillary-clintons-email-server-report

Sources told the Daily Caller News Foundation that a Chinese-state owned firm located in the Washington, D.C., area had access to Clinton's emails in real time courtesy of a code embedded in the New York-based server which then made copies of the emails, some of which contained classified information.

“Code embedded in the New York-based server…” sure sound like a Chinese (computer) virus.