Report of the National Commission for the Review of the Research and Development Programs of the United States Intelligence Community: Special Topic White Paper: The IC's Role Within U.S. Cyber R&D [open pdf - 882KB]
"The national security of the United States requires that our public and private enterprises be safe from cyber exploitation and cyber espionage. […] The most worrisome cyber attacks are believed to be state-sponsored, and some of them may include the use of proxies. Cyber attacks can be designed to deny access to critical services, reduce the reliability and trust of U.S.-based institutions, cause failure in the nation's critical infrastructure, or steal intellectual property, financial resources, and identities. Other attacks are intended to extort, blackmail, or probe for vulnerabilities in preparation for a larger attack. Distributed denial of service (DDoS) attacks may target entire industries, as demonstrated by recent attacks against U.S. financial institutions. In milliseconds, DDoS cyber attacks--with loads measured in hundreds of gigabits per second--can overwhelm the bandwidth of Internet-based services of even large enterprises. When DDoS attacks overwhelm the defenses of a target, they can degrade quality of service, cause localized outages, or mask other attacks. Attacks more sophisticated than DDoS also have been observed. These attacks modify their behavior in near real time in response to the defenses they encounter. Furthermore, attacks of types not yet known may have been executed, or may be ready to be launched at a future time. The Intelligence Community and the Department of Defense, because of both their capabilities and their missions, are at the forefront of understanding, assessing, and countering this growing threat."
Federation of American Scientists: http://www.fas.org/