In this campaign, there are two .hwp documents which are the Hanword Document files.
This document is in .hwp format so it had to be converted it into .docx using BATCHHWPCONV.EXE tool.
One file contains many embedded files, some files are more interesting than others.
which are having embedded base64 encoded powershell script, they can be decoded easily.
After decoding – in this script, APT37 is using it’s technique T1071.001 in which they generally deploys “POST” request to communicate with Command & Control (C2) server.
The C2 url used for making request is the “http[://]ljs5950[.]cafe24[.]com[/]bbs[/]samsung[/]do[.]php”
and from C2 url further plugins are downloaded in APPDATA folder.
This malicious .hwp document on dynamic execution.