stab (someone) in the dark

Translations
ударить (кого-то) в темноте
He decided to stab him in the dark and hope for the best.
Он решил ударить его в темноте и надеяться на лучшее.
Definitions
To attack, harm, or betray someone unexpectedly and without warning, often in a secretive or underhanded way. The phrase combines 'stab in the back' (betrayal) and 'in the dark' (without knowledge or awareness), implying a treacherous act done when the victim is unaware.