Native-born Ukrainian here. It's hard to translate it to english in a way that would make sense. The gist of it is "We beat on the false worker".
Some explanation: "Byom" (the first word) is the "we" form of the base word "bei" which means to beat. Russian is a language where the suffix can change the tense or meaning of the word, similar to Spanish. However, "byom" can me different things, such as to fight, battle, struggle against, etc (both literally and figuratively). "Po" (the middle word) means "on" in this case. The last word is a portmanteau of "Lzhe" and "udarnik". "Lzhe" implies lying or falsehood. "Udarnik" means "hitter" or "striker", but I did a bit of reseach and found out that "Udarnik" was also the name given to Soviet "shock workers" i.e. the workforce.
I don't think they literally beat lazy workers with hammers, but the general idea is to weed out the posers from the "true" workers. Basically a bit of labor propaganda.