Trojan- JS downloader


I have downloaded JS trojan downloader from VirusSign  to analyze behavior of this malware. It was a zip file INC_0987155124US_Apr_19_2019.zip and after extracting it, I got .js file.

On opening JS file in notepad, i saw base64 obfuscated string. After obfuscation JS script, I found, this file has multiple sources/ URL’s to download  SHA256- d6798b62cef08c4f61a30dfa346faf5aa29f9d03e4599ebe5ae910a193087b86

Below are  the URL’s used in JS to download malicious executable files.

Blg3_20042019_4

Below is JS code where it goes to the URL to check whether it’s up else will check another URL to get the malware downloaded on user’s machine.

Blg3_20042019_7

I tried to accessed all four URL’s used in JS script and could able to download malicious .exe files from three of them. One URL was inaccessible.

Blg3_20042019_2.PNG

Below are executable files downloaded from URL’s.

Blg3_20042019_3

When I checked the version and hash of all three files, all were same.

Blg3_20042019_6

Behavior of executable file:

On execution, file get created under C:\Windows\SysWow64 directory under name sourcematrix.exe. 

Blg3_20042019_8

and it also adds to the windows services (services.msc).

Blg3_20042019_9.PNG

Wireshark log shows this malware executable connects to IP address 5[.]230[.]147[.]179

Blg3_20042019_12.PNG

Below is malicious executable file hash

SHA256: D6798B62CEF08C4F61A30DFA346FAF5AA29F9D03E4599EBE5AE910A193087B86

Thank you.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.