TSPY_ZBOT.YYDAY

 Analysis by: Vincent Martin Hermosura

 ALIASES:

PWS:Win32/Zbot (Microsoft), Trojan Horse (Symmantec), RDN/Generic.dx!d2x (Mcafee), Trojan.Win32.Generic!BT (Sunbelt), TR/Beebone.rhwnaey (Antivir), W32/VB.DKF (Authentium), Trojan.GenericKD.1822594 (Bitdefender), W32/Buzus.AIOV!tr (Fortinet), W32/VB.DKF (exact) (Fprot), Trojan.Win32.Buzus (Ikarus), a variant of Win32/Injector.BKYQ trojan (Esset), Suspicious file (Panda), Trojan.Buzus (Vba32)

 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: 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:

246,416 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

04 Oct 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 files:

  • %Application Data%\Opewas\fakyi.exe
  • %Application Data%\Microsoft\Address Book\{user name}.wab~
  • %Application Data%\Microsoft\Address Book\{username}.wab

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

It creates the following folders:

  • %AppDataLocal%\Identities
  • %AppDataLocal%\Identities\{GUID}
  • %AppDataLocal%\Identities\{GUID}\Microsoft
  • %AppDataLocal%\Identities\{GUID}\Microsoft\Outlook Express
  • %Application Data%\Microsoft\Address Book
  • %Application Data%\Opewas
  • %Application Data%\Vyih

(Note: %AppDataLocal% is the Local Application Data folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local on Windows Vista and 7.. %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming 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\Run
{GUID} = "%Application Data%\Opewas\fakyi.exe"

Other System Modifications

This Trojan adds the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
Guedte

HKEY_CURRENT_USER\Software\Microsoft\
Internet Account Manager

HKEY_CURRENT_USER\Software\Microsoft\
Internet Account Manager\Accounts\Bigfoot

HKEY_CURRENT_USER\Software\Microsoft\
Internet Account Manager\Accounts\VeriSign

HKEY_CURRENT_USER\Software\Microsoft\
Internet Account Manager\Accounts\WhoWhere

HKEY_CURRENT_USER\Software\Microsoft\
WAB\WAB4