Symantec: Firms must take steps against DDoS attacks

Companies must protect themselves against distributed denial-of-service attacks such as those that hit Visa and MasterCard's websites on Wednesday, a senior manager at Symantec has said.

Ronnie Ng, senior manager for systems engineering at Symantec Singapore, explained that the distributed denial-of-service (DDoS) attacks were carried out by a readily available toolkit known as low orbit ion cannon (LOIC). This is a network stress-testing application that attempts a DDoS attack on the target site by flooding the server with TCP, UDP and HTTP requests. The intention is to disrupt the service of a particular host. LOIC is one of several free attack toolkits that are readily available on the web, Ng said in an email interview with ZDNet UK's sister site, ZDNet Asia.

Ng admitted that difficulties remain in defending against typically distributed DDoS attacks. "Online merchants will need to audit gateways and firewall rules to ensure they are capable of dealing with small-scale everyday attacks and have comprehensive policies in place to defend themselves against large-scale attacks," he said.

For more on this ZDNet UK-selected story, see Symantec: DDoS attacks hard to defend on ZDNet Asia.