Analysis by: RonJay Kristoffer Caragay
ALIASES:

JS.Downloader (Symantec); JS/Downloader.Agent.67_K (AVG); JS/Nemucod.rp (McAfee)

 PLATFORM:

Windows

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:
 INFORMATION EXPOSURE:

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

  TECHNICAL DETAILS

File Size: 77,949 bytes
File Type: JS
Initial Samples Received Date: 26 Jan 2017

Arrival Details

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Dropping Routine

This Trojan drops the following files:

  • %Temp%\r1.log
  • %Temp%\sijruhireuqfre8643jh6k3.ini
  • %Temp%\{username}xmda.jpg
  • %Temp%\{username}xmdb.jpg
  • %Temp%\{username}xmdc.jpg
  • %Temp%\{username}xmddwwg.gif
  • %Temp%\guildwwg.gif
  • %Temp%\{username}wwg.gif

(Note: %Temp% is the Windows temporary folder, where it usually is C:\Windows\Temp on all Windows operating system versions.)

Other Details

This Trojan connects to the following possibly malicious URL:

  • https://{BLOCKED}vokaveycobexopuloqidchvmei41xupasatesucorimi.returnxyz00.returnxyz01.organiccrap.com/01/dynamikywwg.gif.zip