According to a recent New York Post Article, multiple journalists are currently on the end of government surveillance. The names of the reporters being wiretapped have not been revealed; they are people who have published leaks from the White House in the mainstream media.
The Post reported the journalists in question are not the “target” of the surveillance. The actual targets are the key figures within the White House that are sharing secret information with these reporters. If the White House Staff are caught leaking information to this journalist, they could be prosecuted for leaks.
The method in which the DOJ obtained permission to conduct the surveillance is uncertain. Apparently, the DOJ went through the Foreign Intelligence Surveillance Court. During the height of the NSA scandal, the FISA rubber-stamped all surveillance requests. Reportedly the court has a reputation for serving as a yes man to the White House.