Unusual WhatsApp message with random code sent to a contact [closed]
My friend Alice says she was possibly hacked. Yesterday, her friend Bob said Alice sent him a WhatsApp message with some numbers, and then Bob replied to this message with a thumbs up. Bob says no record of the message appears on their chat, only the thumbs-up reply, which came with an exclamation icon (which usually appears on the first message someone sends to someone who has the auto-delete feature activated on WhatsApp).
Minutes before, Alice's Amazon official verified chat on WhatsApp said "Hello, you answered an automatic message. To know more about orders, please...", but there's no track of which message Alice sent, only Amazon's response.
I know the basics of cybersecurity. Alice has her WhatsApp logged into a Windows laptop via WhatsApp web, a Xiaomi phone and a Xiaomi tablet. My first suspicion was that her WhatsApp web cookies got stolen, as it's too easy to install something in Windows and give admin access. However, I don't see how anyone with a web WhatsApp account could send messages without them getting recorded on the phone as well. At least on the phone, it should show "erased message".
Is there any explanation for this?
PS: I told Alice to log out of everything except for the phone and she did.
