Analysis by: Anthony Joe Melgarejo

ALIASES:

W97M/Bartallex.v (McAfee), VBA/TrojanDownloader.Agent.YO trojan (ESET)

 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: 99,328 bytes
File Type: DOC
Initial Samples Received Date: 28 Jul 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.

Dropping Routine

This Trojan drops the following files:

  • %User Temp%\8.exe
  • %User Temp%\{random numbers}.ps1
  • %User Temp%\{random numbers}.vbs
  • %User Temp%\{random numbers}.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.)

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://{BLOCKED}c.su/5751812.jpg
  • http://{BLOCKED}c.su/5757956.jpg
  • http://{BLOCKED}residency.com/modules/mod_araticlhess/fafa.txt
  • http://{BLOCKED}residency.com/modules/mod_araticlhess/78672738612836.txt
  • http://{BLOCKED}scostainedglassdesignresturation.com/wp-content/themes/ecobiz/ecobiz/css/styles/brown/fafa.txt
  • http://{BLOCKED}scostainedglassdesignresturation.com/wp-content/themes/ecobiz/ecobiz/css/styles/brown/78672738612836.txt