According to Jan Poczobutt, vice president of sales at Barracuda Networks, botnets traditionally only picked on a few computers, are initiated through a command-and-control (C&C) server and were used for spamming during distributed denial of service (DDoS) attacks. Enterprises could simply filter botnets by adding them to the spam list but today, attackers have changed the way they use botnets, Poczobutt noted, speaking to ZDNet Asia in a phone interview on Friday. For example, botnets are able to go into the applications and through a series of apps looking like user request, they can bring down entire applications, he explained.