Analysis by: Francis Xavier Antazo
ALIASES:

TrojanDownloader:W97M/Bartallex.G (Microsoft), VBA/TrojanDownloader.Agent.UQ (ESET), W97M.Downloader(Symantec)

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • 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: 69120 bytes
File Type: DOC
Memory Resident: Yes
Initial Samples Received Date: 15 Jun 2015

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.

Installation

This Trojan drops and executes the following files:

  • %User Temp%\{random numbers}.vbs
  • %User Temp%\{random numbers}.bat
  • %User Temp%\{random numbers}.ps1 (For OS Version Vista and above)
  • %User Temp%\8.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:

  • {BLOCKED}onchar.com/home/wp-includes/fonts/89172387.txt
  • {BLOCKED}onchar.com/home/wp-includes/fonts/lns.txt
  • {BLOCKED}ianz.com/boilerd/keys/89172387.txt
  • {BLOCKED}ianz.com/boilerd/keys/lns.txt