Yes
Lawyer's analysis
Yes
Whether a contract that is not signed by me is valid or not needs to be determined according to the following circumstances:
1. If I authorize others to sign the contract on my behalf, the contract signed by others will also have legal effect on me.
If someone else signs a contract without authorization, I don't recognize his agency authority, and the rights and obligations of the contract shall be borne by the signatory, which has no legal effect on me.
3. If the contract signed by the entrusted agent does not belong to the above situation is valid, the signed cooperation agreement is invalid and not legally binding on you.
legal ground
Article 66 of the General Principles of Civil Law
If there is no agency, beyond the agency or after the termination of the agency, the principal can bear civil liability only after ratification by the principal. If the act is not ratified, the actor shall bear civil liability. Knowing that someone else has committed a civil act in my name without denying it is regarded as consent. If an agent fails to perform his duties and causes damage to the principal, he shall bear civil liability. Where an agent colludes with a third party to harm the interests of the principal, the agent and the third party shall bear joint liability. If a third party knowingly commits a civil act with the actor without the agency right, beyond the agency right or the agency right has been terminated, thus causing damage to others, the third party and the actor shall be jointly and severally liable.