Various forms of information are utilized in a system and accompanying method for making inferences regarding the trustworthiness of a person performing an online transaction and deciding whether to allow the transaction to have material implications. More specifically, the information relates to the online browsing activity of a user and the online transaction being performed by the user. Further, information regarding certain probable characteristics of the user is determined based on a possible association between the user and one or more known entities. Based on the foregoing information, model attributes are derived and provided as input to a fraud determination model. Using this model and one or more of the attributes, a probability that the transaction is fraudulent is determined.