APT16

Between November 26, 2015, and December 1, 2015, known and suspected China-based APT groups launched several spear-phishing attacks targeting Japanese and Taiwanese organizations in the high-tech, government services, media and financial services industries. Each campaign delivered a malicious Microsoft Word document exploiting the aforementioned EPS dict copy use-after-free vulnerability, and the local Windows privilege escalation vulnerability CVE-2015-1701. The successful exploitation of both vulnerabilities led to the delivery of either a downloader that we refer to as IRONHALO, or a backdoor that we refer to as ELMER.