“The FBI is warning that fake online document converters are being used to steal peoples’ information and, in worst-case scenarios, to deploy ransomware on victims’ devices. The warning came last week from the FBI Denver field office, after receiving an increasing number of reports about these types of tools.”
It seems that many of these relate mostly to creating to or from PDF files, but really most good word processors already do that as a built-in function, e.g. free LibreOffice.