Analysis by: Vincent Martin Hermosura
ALIASES:

Troj/Ramnit-EH (Sophos), Trojan horse Zbot.FXC (AVG), TROJ_FORUCON (Beta_Gen), W32/Zbot.CYP!tr (Fortinet), Trojan.Agent (Ikarus), Trojan-Spy.Win32.Zbot.rptj (Kaspersky), PWS:Win32/Zbot (Microsoft), Win32/Spy.Zbot.AAU trojan (Nod32)

 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild:

  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: 1,986,048 bytes
File Type: EXE
Initial Samples Received Date: 21 May 2014

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 the following copies of itself into the affected system:

  • %User Temp%\runwt.exe

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)

Autostart Technique

This Trojan adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\RunOnce
runwt = "%User Temp%\runwt.exe -w"

Other System Modifications

This Trojan adds the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\RunOnce

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
ESENT\Process\{malware file name}

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
ESENT\Process\{malware file name}\
DEBUG

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
ESENT\Process\runwt

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
ESENT\Process\runwt\
DEBUG

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
ESENT\Process\{malware file name}\
DEBUG
Trace Level = ""

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
ESENT\Process\runwt\
DEBUG
Trace Level = ""

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
TrayNotify
BalloonTip = "dword:00000001"

NOTES:

This Trojan connects to the following URLs to get the current date:

  • http://www.amazon.com
  • http://www.aol.com
  • http://www.ask.com
  • http://www.bing.com
  • http://www.facebook
  • http://www.google.com
  • http://www.live.com
  • http://www.msn.com
  • http://www.twitter.com
  • http://www.yahoo.com
  • http://www.youtube.com