The adversary uses Cobalt Strike as framework to manage their compromised systems. We observed the use of Cobalt Strike’s C2 protocol encapsulated in DNS by the adversary in 2017 and 2018. They switched to C2 encapsulated in HTTPS in Q3 2019. An interesting observation is they made use of a cracked/patched trial version of Cobalt Strike. This is important to note because the functionalities of Cobalt Strike’s trial version are limited. More importantly: the trial version doesn’t support encryption of command and control traffic in cases where the protocol itself isn’t encrypted, such as DNS. The DNS-responses weren’t logged. This means that only the DNS C2 leaving the victim’s network was logged. We developed a Python script that decoded and combined most of the logged C2 communication into a human readable format. As the adversary used Cobalt Strike with DNS as command &amp; control protocol, we were able to reconstruct more than two years of adversary activity