TSPY_ZBOT.IA

 Analysis by: kathleenno

 ALIASES:

Trojan.Gen (Symantec); VirTool:Win32/Obfuscator.QG (Microsoft); Trojan-Spy.Win32.Zbot.bwhf (Kaspersky); Mal/Zbot-DE (Sophos)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

 OVERALL RISK RATING:
 REPORTED INFECTION:
 SYSTEM IMPACT RATING:
 INFORMATION EXPOSURE:

  • Threat Type: Spyware

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW


This spyware 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:

203,776 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

04 Aug 2011

Arrival Details

This spyware arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It may be downloaded from the following remote sites:

  • http://{BLOCKED}arkscar.com/arg/arg.exe

Installation

This spyware drops the following files:

  • %Application Data%\{random1}\{random}.exe
  • %Application Data%\{random2}\{random}.{random}

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Windows\Profiles\{user name}\Application Data on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Application Data on Windows NT, and C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, XP, and Server 2003.)

It creates the following folders:

  • %Application Data%\{random1}
  • %Application Data%\{random2}

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Windows\Profiles\{user name}\Application Data on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Application Data on Windows NT, and C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, XP, and Server 2003.)

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{random CLSID} = %Application Data%\{random1}\{random}.exe

Other System Modifications

This spyware adds the following registry keys as part of its installation routine:

HKEY_CURRENT_USER\Software\Microsoft\
{random}

Download Routine

This spyware connects to the following URL(s) to download its configuration file:

  • http://{BLOCKED}rkscar.com/arg/arg.en

Stolen Information

This spyware sends the gathered information via HTTP POST to the following URL:

  • http://{BLOCKED}illaoff.com/art/dfiup.php