Security experts at Check Point that analyzed North Koreas antivirus software SiliVaccine discovered it is based on a 10-year-old anti-malware engine developed by Trend Micro. The software whitelisted mystery malware may be nation-state malware that North Korea wants to use for surveillance purposes. Experts also discovered the use of the Themida and Unopix packers commonly used to make malware analysis very hard. Check Point also discovered that the antivirus solution used a custom encryption protocol to encrypt pattern files.”]
Source: https://securityaffairs.co/wordpress/72040/malware/silivaccine-north-korea.html