Analysis by: Rhena Inocencio

ALIASES:

TrojanDownloader:JS/Nemucod (Microsoft), JS/Nemucod.in (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 as an attachment to email messages spammed by other malware/grayware or malicious users.

  TECHNICAL DETAILS

File Size: Varies
File Type: JS
Initial Samples Received Date: 12 May 2016

Arrival Details

This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users.

Installation

This Trojan drops the following files:

  • Any of the following:
    • %User Temp%\suckit.bat
    • %User Temp%\suc11.05.2016kit.bat

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

Download Routine

This Trojan saves the files it downloads using the following names:

  • Any of the following:
    • %User Temp%\jybOVlVWZEA0cT8.exe
    • %User Temp%\IgVCpC.exe
    • %User Temp%\RAvrFE.exe
    • %User Temp%\HIOIY2aNvjZytV.exe

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://{BLOCKED}adirect.com/lw0old
  • http://{BLOCKED}l.za.pl/8977g78bi
  • http://www.{BLOCKED}dgearchitects.com/8977g78bi
  • http://{BLOCKED}aqeem.com/khd4bf