Secure access first
Use a trusted device, change exposed passwords, revoke unfamiliar sessions and enable multi-factor authentication. Do not share recovery phrases or private keys with anyone offering help.
Preserve the transaction record
Save the transaction hash, network, wallet addresses, amount, date and time. Export account activity and keep the original files unchanged.
Contact the relevant service
Notify the exchange or wallet provider through its official support channel. Include factual identifiers and avoid assumptions about ownership or recovery.
Create a clear timeline
Record what happened, when it was discovered and every action taken afterward. A consistent timeline is more useful than scattered screenshots.