The elite cyber crime group Hellsing strikes back after attack by the rival APT crew known as Naikon. This is the first documented case of APT-on-APT attack that has been witnessed by the experts. The attack was made by experts at Kaspersky Team that provided a detailed analysis of the attack. The Hellsing APT attached a payload used to serve a powerful malware that infects the victims PC. The name Hellsing comes from the project title left by a developer in a malicious source code used by the hacking team.”]
Source: https://securityaffairs.co/wordpress/36002/cyber-crime/hellsing-apt-on-apt-attack.html