WASHINGTON — Four years after the high-profile leaks by former National Security Agency contractor Edward Snowden, the Pentagon’s efforts to defend against insider threats remain insufficient, according to a report by the Defense Department’s Office of Inspector General.

The ability of employees or government contractors to steal and disseminate troves of classified information has alarmed the Defense Department, which has taken multiple steps to stop such occurrences.

“This access [authorized access to U.S. government resources] can provide insiders a unique opportunity to damage the United States through espionage and unauthorized disclosures of national security information,” the report says.

The report cites specific steps that the department has already taken to put an end to insider threats.

“Yet, although the DoD has made progress defending against insider threats, more progress is needed,” the report says.

“Despite efforts to limit insider risks, two contractors working for the National Security Agency removed classified information in 2017, and in at least one instance disclosed classified information detrimental to national security,” according to the report.

Furthermore, the Office of Inspector General “intends to determine whether DoD intelligence community agencies have secured access to and monitored user activity affecting classified enclaves within their agencies,” the report says.