Whatsapp Hacking Issue

My whatsapp has been hacked, and it has been sending messages automatically to frequently contacted contacts. The message consists of one attachment and a text with it, which after clicking on the attachment, same kind of a text and attachments are sent to other contacts independently. This has happened with me second time in one week and it has been happening with other Vendors, distributors and their Purchase & accounts departments. This attachment and text has been circulating independently without the owner's permission and this indicate that they have total access of our WhatsApp. I fear for my personal and financial belongings and registering this complaint with utmost trust on the Cyber cell to act on it immediately and relief me from this trouble.