The director of the Department of Homeland Security's U.S. Computer Emergency Readiness Team (US-CERT) has resigned, several media outlets reported over the weekend.

Mischel Kwon is leaving the post after less than a year, and will soon take a job in the private sector, The Washington Post reports. The newspaper cited anonymous sources who said she was "frustrated by bureaucratic obstacles and a lack of authority to fulfill her mission." She was the fourth director of US-CERT in the last five years.

US-CERT was established in 2003 as an arm of the National Cyber Security Division within the Department of Homeland Security (DHS) in order to protect the nation's Internet infrastructure, including .gov domains.

Kwon's departure is the latest blow to the top of the Obama administration's cyber-security hierarchy. Melissa Hathaway, the president's acting senior director for cyber-space, resigned last week.

For more information, read Government Technology's article about the resignation of US-CERT's director.