“Since [Stuxnet] there's almost a perception that everything is an Advanced Persistent Threat,” said Greg Day, director of security strategy for the U.K. division of information security specialists Symantec, during a presentation to the Counter Terror Expo 2012 in London. He pointed out that most corporate security is focused on advanced threats and the lower-end, “brute force” approach of denial-of-service attacks and defacement of public-facing websites.

“What I think has slipped under the radar is the middle ground, which is persistent and targeted threats, that are taking [known] toolkits and vulnerabilities and saying, 'I'm going to find a company and target them, and I'm going to keep going and going and going until I get in,'” he continued. “The challenge we have is we don't necessarily realize this middle ground exists.”