REDUCTORReductor

We called these new modules ‘Reductor’ after a .pdb path left in some samples. Besides typical RAT functions such as uploading, downloading and executing files, Reductor’s authors put a lot of effort into manipulating digital certificates and marking outbound TLS traffic with unique host-related identifiers. The Kaspersky Attribution Engine shows strong code similarities between this family and the COMPfun Trojan. Moreover, further research showed that the original COMpfun Trojan most probably is used as a downloader in one of the distribution schemes. Based on these similarities, we’re quite sure the new malware was developed by the COMPfun authors.