Murder is a crime on Ferenginar, just as it is in most of the civilised galaxy, at least according to senior Trek producers/writers Ira Steven Behr and Robert Hewitt Wolfe.
With both individuals being strongly involved with writing backstory for the Ferengi on the DS9 TV show, it seems likely that this is as close to canon as we're liable to get.
The following article appeared on the front page of the Ferengi Acquirer on Glorpober fifth, 18,083.
GOUGE-MINING MAGNATE ESCAPES DEATH. WIFE CHARGED IN MURDER ATTEMPT
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Shortly after his rescue, FCA liquidators arrested the victim’s wife, Jubbletta, and charged her with attempted murder. It seems Jubbletta had struck her husband over the head with a bar of latinum, stuffed his unconscious body into his skimmer, and then programmed its autopilot to crash into one of Squeeb’s own gouge mines.
Given attempted murder is a crime, it stands to reason that actual murder would also be a crime.