In 2017, Unit 42 reported on and analyzed a low-volume malware family called Cardinal RAT. This malware family had remained undetected for over two years and was delivered via a unique downloader named Carp Downloader. Since that publication, we have continued to monitor this threat, resulting in the discovery of a series of attacks using an updated version of Cardinal RAT. A series of modifications have been made to the RAT, many of which are used to evade detection and hinder analysis.   

https://unit42.paloaltonetworks.com/cardinal-rat-sins-again-targets-israeli-fin-tech-firms/