A cyberattack on Norway’s government ministries uncovered last week had exploited a vulnerability linked to mobile device management and lasted at least four months, according to Norwegian and US cybersecurity agencies.

A vulnerability affecting Ivanti Endpoint Manager Mobile allowed advanced persistent threat actors — a reference used to hackers often sponsored by a government — to gather information from several Norwegian organizations, and gain access to and compromise a Norwegian government agency’s network from at least April, US and Norwegian cyber security agencies said in a joint advisory dated Aug. 1.

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“Mobile device management systems are attractive targets for threat actors because they provide elevated access to thousands of mobile devices,” the US Cybersecurity and Infrastructure Security Agency and Norway’s National Cyber Security Centre said. Ivanti released patches for the vulnerabilities on July 23 and July 28, the advisory said.

Aftenposten reported the news earlier.