Multiple emoji reacts in personal chat

I recently shifted from android to ios. I used ult data to transfer Google drive WhatsApp backup to iCloud. Now in my WhatsApp chats in iPhone… all the personal messages have been reacted with emojis from people who are not even in the group. Example- if I am chatting with my friend after some time his msgs were reacted by emojis by random ppl from my contact list. Is it a virus ? I am apprehensive