The most infamous (and heinous) oft sighted example...
https://en.wikipedia.org/wiki/Russian_apartment_bombings
And there are plenty of more recent allegations such as the framing of North Korea for the attempts to disrupt the Winter Olympics:
https://www.wired.com/story/russia-false-flag-hacks/
Parkland shootings etc etc
http://www.politifact.com/truth-o-meter/article/2018/feb/22/...
https://www.washingtonpost.com/opinions/after-the-parkland-s...