OTP Flood attack on Uber?
A user receives Uber OTP codes via WhatsApp every day since August 5. The sender shows up as Uber with a verified business account. The user has never registered an Uber account.
Context first: Uber does deliver OTPs over WhatsApp, so the channel alone proves nothing. These look are real codes, from Uber legitimate WhatsApp Business account, not smishing.
Technical hypothesis. The OTP trigger on the WhatsApp channel doesn’t seem to have effective per-recipient rate limiting, while SMS appears to be capped. That would explain the channel choice, you hammer where there’s no limit. The trigger also seems independent of account state, it fires whether the number is registered or not.
I checked for a link to a separate exposure. The user’s email shows up in infostealer and combolist data, but the phone number is not present in that data. The two look unrelated.
What I can’t place is the threat actor’s objective. Only the victim receives the code, so either a contact will eventually ask them to forward it, which puts us in social engineering, or the code is irrelevant and this is harassment, noise, or number enumeration. So far no one has reached out asking for a code.
Thanks to anyone willing to weigh in.