Carbanak is one of the most full-featured, dangerous malware that belongs to an APT-style cybercriminal group. Source code was 20MB comprising 755 files, with 39 binaries and 100,000 lines of code. Researchers have plans to release a 4-part series of articles detailing CARBANAK features and analysis based upon its source code and reverse engineering. Group was first exposed in 2015 as financially-motivated cybercriminals, and three suspects were arrested last year in Europe.
Source: https://thehackernews.com/2019/04/carbanak-malware-source-code.html