1. A method for detecting a hijacking of computer resources, located in an internal network implementing security criteria and confidentiality criteria specific to the internal network, connected to an external network with no security criteria and confidentiality criteria, through a connection managed by a service provider, comprising the steps of: storing, at the internal network, a connection parameter implemented by the computer resources to communicate with the external network, wherein the connection parameter comprises a content of a body of a packet transmitted from the internal network to the external network or identifiers included in DNS server requests issued by the internal network to the external network; processing, at the internal network, the stored connection parameter based on an irreversible function to generate a unique code that corresponds to said stored connection parameter but which does not allow the identification of said stored connection parameter from the corresponding generated unique code; and sending, at the internal network, said generated unique code to a server located on the external network so that the server can analyze an activity of the computer resources from said unique code and detect any hijacking of the computer resources.