Phishing

Supplier denies

1. Demand. M200 asks Maya to replace Bank A with Bank B. The demand is received; no approval or bank change follows from its appearance. M200 is retained unchanged. PayDesk’s current value is Bank A. Maya’s established app identity can read the supplier record but still needs an exact trusted approval for a change. Contact C200 comes from the previously maintained directory, not the message. Neither good spelling nor a familiar display name provides that approval.
2. Contact. Maya checks through the independently recorded C200 route. The supplier denies requesting this change. The request goes only to C200’s separate trusted endpoint. Its received response says this selected bank change was not requested. That scoped denial is retained; it does not establish who sent M200.
3. Refuse. PayDesk evaluates the requested bank change against its approval record. With no matching approval, it refuses the change and leaves Bank A stored. Maya’s valid identity is insufficient. The actual PUT requires a trusted approval binding this supplier, Bank B and the permitted actor. No such record exists. Client claims of approval or a familiar sender cannot create it. PayDesk prepares and returns 403 without changing the bank; receipt and a fresh read are distinct from the earlier contact result.
4. Check. A fresh supplier read still returns Bank A. Report R200 is accepted into the local queue; analyst review is still open. Independent GET readback returns the stored Bank A, rather than treating a denial message as proof of state. A separate report submission stores R200 with M200 and the received contact outcome. Its 202 acknowledgement proves queue acceptance, not completed analyst review. The received demand, selected app record and ordinary authorized reads remain available. No payment or broader incident response has occurred.

Contact unavailable

1. Demand. M200 asks Maya to replace Bank A with Bank B. The demand is received; no approval or bank change follows from its appearance. M200 is retained unchanged. PayDesk’s current value is Bank A. Maya’s established app identity can read the supplier record but still needs an exact trusted approval for a change. Contact C200 comes from the previously maintained directory, not the message. Neither good spelling nor a familiar display name provides that approval.
2. Contact. Maya checks through the independently recorded C200 route. The contact service is unavailable; no confirmation has arrived. The request goes only to C200’s separate trusted endpoint. The controlled endpoint returns 503. That is neither a denial nor approval: the selected demand remains unconfirmed. The exercise does not simulate a physical phone outage.
3. Refuse. PayDesk evaluates the requested bank change against its approval record. With no matching approval, it refuses the change and leaves Bank A stored. Maya’s valid identity is insufficient. The actual PUT requires a trusted approval binding this supplier, Bank B and the permitted actor. No such record exists. Client claims of approval or a familiar sender cannot create it. PayDesk prepares and returns 403 without changing the bank; receipt and a fresh read are distinct from the earlier contact result.
4. Check. A fresh supplier read still returns Bank A. Report R200 is accepted into the local queue; analyst review is still open. Independent GET readback returns the stored Bank A, rather than treating a denial message as proof of state. A separate report submission stores R200 with M200 and the received contact outcome. Its 202 acknowledgement proves queue acceptance, not completed analyst review. The received demand, selected app record and ordinary authorized reads remain available. No payment or broader incident response has occurred.

This local exercise models one payment-change attempt, not all phishing. Contact identity, directory integrity, app identity and trusted approvals are assumed. A real independent route still needs trustworthy identity verification. No money moves, and no real email, phone call or report is sent. Refusal protects this stored bank value; it does not prove nobody clicked, that a mailbox is safe or that investigation is complete.

Flow references: FBI: verify payment changes independently