whispering campaign

/W IH1 S P ER0 IH0 NG K AE0 M P EY1 N/
noun
  1. 1

    A method of persuasion in which damaging rumors or innuendo are deliberately spread concerning a person or other target, while the source of the rumors tries to avoid detection.

Translate “whispering campaign” into another language

Source: https://en.wiktionary.org/wiki/whisper%20campaign, https://en.wiktionary.org/wiki/whispering%20campaign