false flag

Short definition from Wiktionary

Noun

1. 1
   A ruse, in the days of sail, in which an attacking ship would fly the colours of its enemy until close enough to open fire.
2. 2
   A diversionary or propaganda tactic of deceiving an adversary into thinking that an operation was carried out by another party.
3. 3
   Alternative form of false flag.

Verb

1. 1
   To target someone or something with a false flag or ruse.