  Botnets are networks of compromised computers with malicious code which are
remotely controlled and which are used for starting distributed denial of
service (DDoS) attacks, sending enormous number of e-mails (SPAM) and other
sorts of attacks. Defense against modern Botnets is a real challenge. This
paper offers several strategies for defense against Botnets with a list and
description of measures and activities which should be carried out in order to
establish successful defense. The paper also offers parallel preview of the
strategies with their advantages and disadvantages considered in accordance
with various criteria.
