Shares of the capital stock in a private corporation may be attached by actually seizing the certificate, or certificates, or by leaving a copy of the attachment with the clerk of such corporation, and such attachment shall be valid except as to holders for value. After receiving notice of the attachment, if the defendant transfers such stock or, if he or she has not previously transferred or pledged such stock, he or she refuses to deliver the same to the attaching officer on demand, he or she shall be liable for the conversion of the same. The purchaser of such stock at an execution sale shall cause the certificate, or certificates, of such stock with an attested copy of the execution and officers' return thereon to be left with the clerk of the corporation within 12 days after the sale, and the title of the stock so sold shall vest in the purchaser.