The present invention discloses a method and system configured for monitoring and verifying software behavior, comprising: receiving, by a software behavior verification system based on a physical hardware system, legal user behavior data containing user activities performed during legal electronic transactions and storing the legal user behavior data as a software behavior model; monitoring, by a software behavior monitor, data packets transmitted in a transaction, and sending data packets to the software behavior verification system; retrieving, by the behavior verification system, expected key sequences and information in the data packets; comparing the key sequences and information retrieved from the data packets with that of the software behavior model; if the key sequences and information retrieved from the data packets does not consistence with the software behavior model, it is determined that the transaction is an illegal electronic transactions, and the transaction is closed.