Mo. Rev. Stat. § 521.070
The bond shall be executed by the plaintiff, or some responsible person as principal, and one or more sureties, resident householders of the county in which the action is to be brought, in a sum at least double the amount sworn to in the affidavit, payable to the state of Missouri, conditioned that the plaintiff shall prosecute his action without delay and with effect, refund all sums of money that may be adjudged to be refunded to the defendant, or found to have been received by the plaintiff and not justly due to him, and pay all damages and costs that may accrue to any defendant, garnishee or interpleader by reason of the attachment, or any process or proceeding in the suit, or by reason of any judgment or process thereon, and pay all damages and costs that may accrue to any sheriff or other officer by reason of acting under the writ of attachment, following the instructions of the plaintiff.
§ 521.070, RSMo