Whose doing is this?
The prank must be my little brother's doing.
This graffiti is the work of a kid from the neighborhood.
The candy disappearing from the fridge must be my little brother's doing.
The scratch on the wall seems to be someone unknown's doing.
所業 is a literary, rather old-fashioned word for one's deeds and usually implies wrongdoing, whereas 仕業 is the everyday word used the same way.
犯行 specifically means a criminal act, while 仕業 is broader and can describe any mischievous or blameworthy deed, not necessarily a crime.
仕草 (a gesture or mannerism) looks similar to 仕業 (a deed, often blameworthy) but the two refer to completely different things.
Standard kanji spelling; the most common written form.
Rarely used kanji form; learners will almost always encounter 仕業.
Compound of 仕 (し, 'to do') and 業 (わざ, 'work, deed'). The reading しわざ is a straightforward combination of the on'yomi of 仕 and the kun'yomi of 業.