Short answer. Not by seizing certificates. The rule directs the sheriff to leave a copy of the writ with the president or managing agent of the corporation, together with a notice stating that your stock or interest is attached in pursuance of the writ. Service on the company is the act.
What the law says
(c) Stocks or shares, or an interest in stocks or shares, of any corporation or company, by leaving with the president or managing agent thereof, a copy of the writ, and a notice stating that the stock or interest of the party against whom the attachment is issued is attached in pursuance of such writ
Rule 57, Section 7 — Attachment of real and personal property; recording thereof. Read the full provision →
Attachment by service on the company, not by seizure
The rule prescribes a different method for each kind of property, and shares get their own paragraph. Stocks or shares, or an interest in stocks or shares, of any corporation or company are attached by leaving with the president or managing agent a copy of the writ and a notice that the stock or interest of the party against whom the attachment is issued is attached in pursuance of the writ. Nothing is physically taken.
Why the certificate is not the target
This method exists because a share is a bundle of rights against the corporation, not a chattel that happens to be printed on paper. Holding the certificate would not stop a transfer being recorded on the corporation's books, and destroying or hiding it would not extinguish the shareholding. Serving the corporation reaches the entity that maintains the record of ownership, which is where a transfer would otherwise be given effect.
Who counts as the right person to serve
The paragraph names two offices: the president, or the managing agent. That is narrower than it may appear, and it is worth checking against what actually happened in your case. Service left with a receptionist, a branch clerk, or an officer who is neither of those does not obviously satisfy the wording. The notice content is prescribed too — it must state that the stock or interest of the party against whom the attachment is issued is attached under the writ.
Interests in shares, and property held elsewhere
The words an interest in stocks or shares extend the paragraph beyond outright registered ownership. Other paragraphs of the same rule cover other assets by their own methods: personal property capable of manual delivery by taking it into custody with a receipt, and debts and credits, including bank deposits, by leaving the writ and notice with the person owing the debt or holding the property. If property is in custodia legis, a copy of the writ is filed with the court or agency concerned.