arrow_back
search
close

TSPY_ZBOT.YVAGX

August 01, 2014
 Analysis by: RonJay Kristoffer Caragay
 ALIASES:

Trojan-Spy.Win32.Zbot.tpzc (Kaspersky); a variant of Win32/Injector.BIPB (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: Spyware

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet, Dropped by other malware

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 modifies Internet Explorer security settings. This puts the affected computer at greater risk, as it allows malicious URLs to be accessed by the computer.

  TECHNICAL DETAILS

File Size:

292,728 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

28 Jul 2014

Payload:

Connects to URLs/IPs, Downloads files

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.

Installation

This spyware drops the following files:

  • %Application Data%\{random folder 1}\{random file name}.exe
  • %Application Data%\{random folder 2}\{random file name}.{random extension}
  • %Application Data%\{random folder 2}\{random file name}.tmp
  • %Application Data%\Microsoft\Address Book\{user name}.wab
  • %Application Data%\Microsoft\Address Book\{user name}.wab~
  • %System Root%\debug.txt

(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.. %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)

It creates the following folders:

  • %Application Data%\{random folder 1}
  • %Application Data%\{random folder 2}

(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.)

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
{GUID} = "%Application Data%\{random folder 1}\{random file name}.exe"

Other System Modifications

This spyware adds the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
{random key 1}

HKEY_CURRENT_USER\Software\Microsoft\
WAB\WAB4

HKEY_CURRENT_USER\Software\Microsoft\
WAB\WAB4\WAB File Name

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
WAB\WAB4
OlkContactRefresh = "0"

HKEY_CURRENT_USER\Software\Microsoft\
WAB\WAB4
OlkFolderRefresh = "0"

HKEY_CURRENT_USER\Software\Microsoft\
WAB\WAB4
FirstRun = "1"

HKEY_CURRENT_USER\Software\Microsoft\
WAB\WAB4\WAB File Name
(Default) = "%Application Data%\Microsoft\Address Book\{user name}.wab"

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Privacy
CleanCookies = "0"

HKEY_CURRENT_USER\Software\Microsoft\
{random key 1}
{random 2} = "{hex values}"

HKEY_CURRENT_USER\Software\Microsoft\
{random key 1}
{random 1} = "{hex values}"

Web Browser Home Page and Search Page Modification

This spyware modifies Internet Explorer zone settings.

Other Details

This spyware connects to the following possibly malicious URL:

  • http://{BLOCKED}lip.com.tr/images/pack/joel.jpeg
  • http://{BLOCKED}.{BLOCKED}.105.60/page/logon/add/ol.bin
  • http://{BLOCKED}.{BLOCKED}.105.60/page/logon/add/sa.php

  SOLUTION

Minimum Scan Engine:

9.700

FIRST VSAPI PATTERN FILE:

10.950.04

FIRST VSAPI PATTERN DATE:

28 Jul 2014

VSAPI OPR PATTERN File:

10.951.00

VSAPI OPR PATTERN Date:

28 Jul 2014

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

Step 2

Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.

Step 3

Restart in Safe Mode

[ Learn More ]

Step 4

Delete this registry key

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

 
  • In HKEY_CURRENT_USER\Software\Microsoft
    • WAB

Step 5

Delete this registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • {GUID} = "%Application Data%\{random folder 1}\{random file name}.exe"
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Privacy
    • CleanCookies = "0"

Step 6

Reset Internet security settings

[ Learn More ]

Step 7

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TSPY_ZBOT.YVAGX. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.

Step 8

The following created files/folders/registry keys/registry entries cannot be identified by the user since there are no reference values in the created key. The only way it can be identified is by comparing the present system information with a backup. Note that the said components do not have to be deleted since it won't be harmful to the system.

  • HKEY_CURRENT_USER\Software\Microsoft
    • {random key 1}
  • HKEY_CURRENT_USER\Software\Microsoft\{random key 1}
    • {random 1} = "{hex values}"
  • HKEY_CURRENT_USER\Software\Microsoft\{random key 1}
    • {random 2} = "{hex values}"
  • %Application Data%\{random folder 1}
  • %Application Data%\{random folder 2}


Did this description help? Tell us how we did.