Analysis by: Mark Joseph Manahan
 Modified by: Adrian Cofreros

ALIASES:

PWS:Win32/Zbot(Microsoft),Trojan-Spy.Win32.Zbot.tqgi(Kaspersky),Win32/Spy.Zbot.ABP(ESET)

 PLATFORM:

Windows

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

  • Threat Type: Spyware

  • Destructiveness: No

  • Encrypted:

  • 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: 282,750 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 22 Oct 2014

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 copies of itself into the affected system:

  • %Application Data%\{random folder name}\{random file name 1}.exe
  • %System%\{random file name 2}.exe

(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming 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.. %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
{random} = "%Application Data%\{random folder name}\{random file name 1}.exe"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{random} = "%Application Data%\{random folder name}\{random file name 1}.exe"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SecurityCenterServer{random value}
DisplayName = "Security Center Server - {random value}"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SecurityCenterServer{random value}
ErrorControl = "1"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SecurityCenterServer{random value}
Type = "10"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SecurityCenterServer{random value}
Start = "2"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SecurityCenterServer{random value}
ObjectName = "LocalSystem"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SecurityCenterServer{random value}
ImagePath = "%System%\{random file name 2}.exe" -service "%Application Data%\{random folder name}\{random file name 1}.exe"

It drops the following files:

  • %Windows%\Tasks\Security Center Update - {value}.job

(Note: %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.)

Other System Modifications

This spyware adds the following registry keys:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SecurityCenterServer{random value}

HKEY_CURRENT_USER\Software\PRQzDA

HKEY_CURRENT_USER\Software\Pyychvalba

HKEY_LOCAL_MACHINE\SOFTWARE\PRQzDA

HKEY_LOCAL_MACHINE\SOFTWARE\Pyychvalba

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Pyychvalba
License = "0x000001bc"

HKEY_LOCAL_MACHINE\SOFTWARE\Pyychvalba
License = "0x000001bc"

It deletes the following registry keys:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Control\SafeBoot

Other Details

This spyware connects to the following possibly malicious URL:

  • http://{BLOCKED}-vaper.su/b/opt/{value}
  • http://{BLOCKED}ervant.su/b/opt/{value}
  • http://{BLOCKED}s-pets.su/b/opt/{value}

NOTES:

It connects to the following:

  • www.google.com

  SOLUTION

Minimum Scan Engine: 9.700
VSAPI OPR PATTERN File: 11.213.00
VSAPI OPR PATTERN Date: 15 Oct 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

Identify and delete files detected as TSPY_ZBOT.SMX1 using either the Startup Disk or Recovery Console

[ 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_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services
    • SecurityCenterServer{random value}
  • In HKEY_CURRENT_USER\Software
    • PRQzDA
  • In HKEY_CURRENT_USER\Software
    • Pyychvalba
  • In HKEY_LOCAL_MACHINE\SOFTWARE
    • PRQzDA
  • In HKEY_LOCAL_MACHINE\SOFTWARE
    • Pyychvalba

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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • {random} = "%Application Data%\{random folder name}\{random file name 1}.exe"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • {random} = "%Application Data%\{random folder name}\{random file name 1}.exe"

Step 6

Search and delete these files

[ Learn More ]
There may be some files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.
  • %Windows%\Tasks\Security Center Update - {value}.job

Step 7

Scan your computer with your Trend Micro product to delete files detected as TSPY_ZBOT.SMX1. 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

Restore this deleted registry key/value from backup

*Note: Only Microsoft-related keys/values will be restored. If the malware/grayware also deleted registry keys/values related to programs that are not from Microsoft, please reinstall those programs on your computer.

  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control
    • SafeBoot


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