What is the test for malicious prosecution against an attorney?

"The propriety of a cause of action for malicious prosecution against an attorney, unlike a cause of action sounding in negligence, is not based on the legal question of whether a duty of care exists and has been breached. Rather, a malicious prosecution cause of action is bottomed on the allegation and proof of the following three factors: (1) the prior civil action against the plaintiff must have terminated in the plaintiff's favor; (2) a defendant-attorney must have lacked probable cause in representation of his client in the prior action; and (3) the defendant-attorney must have acted maliciously therein. [Citation.] If the plaintiff fails to sustain the burden of proof in demonstrating the existence of any one of these three factors, the plaintiff loses." (Weaver v. Superior Court, supra, 95 Cal.App.3d at p. 192, 156 Cal.Rptr. 745.)