The meaning of the word "clean government": mainly refers to the fact that government workers do not abuse power for personal gain when performing their functions, but act fairly and honestly; Sniper means: waiting for an opportunity to attack the enemy. For example, this is what we call a sniper in the war.
Besides, as for the word "attack on integrity", it is the name of a TV series recently broadcast. It mainly tells a group of friends who grew up together. A building collapse accident separated them and completely changed their fate. When they meet again after many years, their identities are different, and there is a struggle between justice and friendship.