[walterbell]

One effort at a standard, http://stix.mitre.org

"STIX™ is a collaborative community-driven effort to define and develop a standardized language to represent structured cyber threat information. The STIX Language intends to convey the full range of potential cyber threat information and strives to be fully expressive, flexible, extensible, automatable, and as human-readable as possible. All interested parties are welcome to participate in evolving STIX as part of its open, collaborative community."

http://stix.mitre.org/language/version1.1.1/samples.html