Dantas de Medeiros, Teobaldo A.Pires, Paulo S. MottaFlegel, UlrichMeier, Michael2019-10-162019-10-1620043-88579-375-Xhttps://dl.gi.de/handle/20.500.12116/29201This paper presents a system developed in Linux aiming the protection of local area networks containing Windows workstations against malicious agents. The developed solution, named LIV - Linux Integrated Viruswall, besides filtering SMTP, HTTP and FTP traffic destined to the protected network, is capable of detecting malicious agents propagation in the local area network using a technique that we call 'sharing-trap'. Compromised workstations are isolated from the network and their users are notified, stopping the malicious agent's spread. Results collected from a network protected by LIV, containing thousands of Windows workstations, are presented and discussed. This paper includes information about the recent incident caused by MyDoom worm.enText/Conference Paper1617-5468