1. A method for detecting attackers that are interested in attacking an organization's infrastructure during the reconnaissance phase of an Advanced Persistent Threat (APT), said method comprising: a. extracting actual user profiles from social networks; b. generating artificial profiles for artificial users from said extracted actual user profiles; c. creating artificial user accounts for said artificial users; d. adding said artificial user accounts to social networks and to employee contact lists; e. creating email accounts for each of said artificial users; f. monitoring the activity of said artificial user accounts in the social networks; g. monitoring the activity of said email accounts; and h. reporting as suspicious all attempts of third parties to contact said artificial user accounts and said email accounts of said artificial users.