text: Denial-of-service attacks are a serious threat—but only if you’re a target
  
  By Zak StamborManaging Editor
  
  While a recent attack brought down a spam-fighting vendor’s site, few elsewhere were impacted.
  
  Several high-profile web sites have gone down in the past few weeks. For instance, multichannel pharmacy retailer Rite Aid Corp. was inaccessible earlier this week for unknown reasons. And cyber attacks took down the web sites of American Express Co. and Bank of America Corp. yesterday.
  
  The number of cyberattacks is growing. Prolexic Technologies Inc., a vendor that protects companies from such web site attacks, says that attacks against its global base of e-commerce clients rose 19% in the fourth quarter of 2012 compared to the same period a year earlier.
  
  That’s why retailers should prepare for how they can deal with a distributed denial of service, or DDoS, attack, which occurs when perpetrators attempt to knock a site offline by sending an overwhelming volume of traffic to it, experts say. That means being prepared by monitoring their web performance, as well as crafting an action plan that includes clear instructions on what to do if an attack occurs. They should also give their employees established roles should an attack occur. That way they can spring into action if an attack arises.
  
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  For instance, when American Express noticed its site slowing down, disrupting customers’ ability to access their account information, it launched its plan, says an American Express spokeswoman. The procedures, she says, helped stablize the site after a few hours. She also says there is no evidence that any customer data was compromised.
  
  However, if a retailer isn’t the focus of criminals committing an attack they’re not likely to feel the residual effects from such an attack, says Aaron Rudger, senior marketing manager at Keynote Systems Inc., a web performance monitoring firm. Rudger says last week’s large-scale attack on spam-fighting vendor Spamhaus caused www.spamhaus.org to go down, but did not appear to have a noticeable effect on other sites, including retailer Netflix Inc., which some reports said experienced delays. Rudger’s observation stems from Keynote’s analysis of its 275 measurement computers around the globe that found site performance in Europe, as well as the United States, was “pretty consistent and normal” when the attack took place.
  
  “A casual user in London doing online shopping from her couch during the time frame when the massive DDoS attack took place wouldn’t notice,” he says. “Certainly she wasn’t interrupted.”
  
  In order to have an impact on a site like Netflix during a similar type of attack, criminals would have to intentionally target that retailer as part of the attack or target something meaningful to Netflix in terms of how the site is hosted, such as its cloud computing service. Rudger says.