TSPY_ZBOT.SMMB
Trojan.Gen (Symantec); Trojan.Win32.Jorik.Zbot.y (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt); Trojan horse Generic18.AZRR (AVG)
Windows 2000, Windows XP, Windows Server 2003
![](/vinfo/imgFiles/legend.jpg)
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
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 creates the following folders:
- %User Profile%\Microsoft\HTML Help
(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)
Autostart Technique
This spyware modifies the following registry entries to ensure it automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
userinit = "%System%\userinit.exe,%System%\twext.exe,"
(Note: The default value data of the said registry entry is %Windows%\system32\userinit.exe,.)
Other System Modifications
This spyware deletes the following files:
- %System%\twext.exe
(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)
It adds the following registry keys:
HKEY_CURRENT_USER\software\microsoft\
windows\currentversion\explorer\
{0060FD7F-DCFF-4402-F399-837C709A807C}
HKEY_CURRENT_USER\software\microsoft\
windows\currentversion\explorer\
{02000000-DCFF-4402-F399-837C709A807C}
HKEY_CURRENT_USER\software\microsoft\
windows\currentversion\explorer\
{C4090000-DCFF-4402-F399-837C709A807C}
HKEY_CURRENT_USER\software\microsoft\
windows\currentversion\explorer\
{40090000-DCFF-4402-F399-837C709A807C}
HKEY_CURRENT_USER\software\microsoft\
windows\currentversion\explorer\
{D4090000-DCFF-4402-F399-837C709A807C}
HKEY_CURRENT_USER\software\microsoft\
windows\currentversion\explorer\
{CC090000-DCFF-4402-F399-837C709A807C}
HKEY_CURRENT_USER\Software\Microsoft\
ActiveMovie\devenum\{4EFE2452-168A-11D1-BC76-00C04FB9453B}
HKEY_CURRENT_USER\Software\Microsoft\
ActiveMovie\devenum\{4EFE2452-168A-11D1-BC76-00C04FB9453B}\
Default MidiOut Device
HKEY_CURRENT_USER\Software\Microsoft\
ActiveMovie\devenum\{E0F158E1-CB04-11D0-BD4E-00A0C911CE86}
HKEY_CURRENT_USER\Software\Microsoft\
ActiveMovie\devenum\{E0F158E1-CB04-11D0-BD4E-00A0C911CE86}\
Default DirectSound Device
HKEY_CURRENT_USER\Software\Microsoft\
Multimedia\ActiveMovie\Filter Cache
It adds the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
ActiveMovie\devenum\{4EFE2452-168A-11D1-BC76-00C04FB9453B}\
Default MidiOut Device
FriendlyName = "Default MidiOut Device"
HKEY_CURRENT_USER\Software\Microsoft\
ActiveMovie\devenum\{4EFE2452-168A-11D1-BC76-00C04FB9453B}\
Default MidiOut Device
CLSID = "{07B65360-C445-11CE-AFDE-00AA006C14F4}"
HKEY_CURRENT_USER\Software\Microsoft\
ActiveMovie\devenum\{4EFE2452-168A-11D1-BC76-00C04FB9453B}\
Default MidiOut Device
FilterData = "{random values}"
HKEY_CURRENT_USER\Software\Microsoft\
ActiveMovie\devenum\{4EFE2452-168A-11D1-BC76-00C04FB9453B}\
Default MidiOut Device
MidiOutId = "ffffffff"
HKEY_CURRENT_USER\Software\Microsoft\
ActiveMovie\devenum\{E0F158E1-CB04-11D0-BD4E-00A0C911CE86}\
Default DirectSound Device
FriendlyName = "Default DirectSound Device"
HKEY_CURRENT_USER\Software\Microsoft\
ActiveMovie\devenum\{E0F158E1-CB04-11D0-BD4E-00A0C911CE86}\
Default DirectSound Device
CLSID = "{79376820-07D0-11CF-A24D-0020AFD79767}"
HKEY_CURRENT_USER\Software\Microsoft\
ActiveMovie\devenum\{E0F158E1-CB04-11D0-BD4E-00A0C911CE86}\
Default DirectSound Device
FilterData = "{random values}"
HKEY_CURRENT_USER\Software\Microsoft\
ActiveMovie\devenum\{E0F158E1-CB04-11D0-BD4E-00A0C911CE86}\
Default DirectSound Device
DSGuid = "{00000000-0000-0000-0000-000000000000}"
HKEY_CURRENT_USER\Software\Microsoft\
Multimedia\ActiveMovie\Filter Cache
0 = "{random values}"
It modifies the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
MediaPlayer
MP2.SaveDir = "%Program Files%\Windows Media Player"
(Note: The default value data of the said registry entry is %Program Files%\Windows Media Player.)
It deletes the following registry keys:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\MUILanguages\
FileVersions
Dropping Routine
This spyware drops the following files:
- %User Profile%\HTML Help\hh.dat
- %System%\twext.exe
(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.. %System% is the Windows system folder, which is usually C:\Windows\System32.)
Other Details
This spyware connects to the following possibly malicious URL:
- http://{BLOCKED}tschmeisterin.at/images/c1.bin
This report is generated via an automated analysis system.
SOLUTION
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
Identify and delete files detected as TSPY_ZBOT.SMMB using either the Startup Disk or Recovery Console
Step 3
Delete this registry key
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\explorer
- {0060FD7F-DCFF-4402-F399-837C709A807C}
- In HKEY_CURRENT_USER\software\microsoft\windows\currentversion\explorer
- {02000000-DCFF-4402-F399-837C709A807C}
- In HKEY_CURRENT_USER\software\microsoft\windows\currentversion\explorer
- {C4090000-DCFF-4402-F399-837C709A807C}
- In HKEY_CURRENT_USER\software\microsoft\windows\currentversion\explorer
- {40090000-DCFF-4402-F399-837C709A807C}
- In HKEY_CURRENT_USER\software\microsoft\windows\currentversion\explorer
- {D4090000-DCFF-4402-F399-837C709A807C}
- In HKEY_CURRENT_USER\software\microsoft\windows\currentversion\explorer
- {CC090000-DCFF-4402-F399-837C709A807C}
- In HKEY_CURRENT_USER\Software\Microsoft\ActiveMovie\devenum
- {4EFE2452-168A-11D1-BC76-00C04FB9453B}
- In HKEY_CURRENT_USER\Software\Microsoft\ActiveMovie\devenum\{4EFE2452-168A-11D1-BC76-00C04FB9453B}
- Default MidiOut Device
- In HKEY_CURRENT_USER\Software\Microsoft\ActiveMovie\devenum
- {E0F158E1-CB04-11D0-BD4E-00A0C911CE86}
- In HKEY_CURRENT_USER\Software\Microsoft\ActiveMovie\devenum\{E0F158E1-CB04-11D0-BD4E-00A0C911CE86}
- Default DirectSound Device
- In HKEY_CURRENT_USER\Software\Microsoft\Multimedia\ActiveMovie
- Filter Cache
Step 4
Delete this registry value
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\ActiveMovie\devenum\{4EFE2452-168A-11D1-BC76-00C04FB9453B}\Default MidiOut Device
- FriendlyName = "Default MidiOut Device"
- In HKEY_CURRENT_USER\Software\Microsoft\ActiveMovie\devenum\{4EFE2452-168A-11D1-BC76-00C04FB9453B}\Default MidiOut Device
- CLSID = "{07B65360-C445-11CE-AFDE-00AA006C14F4}"
- In HKEY_CURRENT_USER\Software\Microsoft\ActiveMovie\devenum\{4EFE2452-168A-11D1-BC76-00C04FB9453B}\Default MidiOut Device
- FilterData = "{random values}"
- In HKEY_CURRENT_USER\Software\Microsoft\ActiveMovie\devenum\{4EFE2452-168A-11D1-BC76-00C04FB9453B}\Default MidiOut Device
- MidiOutId = "ffffffff"
- In HKEY_CURRENT_USER\Software\Microsoft\ActiveMovie\devenum\{E0F158E1-CB04-11D0-BD4E-00A0C911CE86}\Default DirectSound Device
- FriendlyName = "Default DirectSound Device"
- In HKEY_CURRENT_USER\Software\Microsoft\ActiveMovie\devenum\{E0F158E1-CB04-11D0-BD4E-00A0C911CE86}\Default DirectSound Device
- CLSID = "{79376820-07D0-11CF-A24D-0020AFD79767}"
- In HKEY_CURRENT_USER\Software\Microsoft\ActiveMovie\devenum\{E0F158E1-CB04-11D0-BD4E-00A0C911CE86}\Default DirectSound Device
- FilterData = "{random values}"
- In HKEY_CURRENT_USER\Software\Microsoft\ActiveMovie\devenum\{E0F158E1-CB04-11D0-BD4E-00A0C911CE86}\Default DirectSound Device
- DSGuid = "{00000000-0000-0000-0000-000000000000}"
- In HKEY_CURRENT_USER\Software\Microsoft\Multimedia\ActiveMovie\Filter Cache
- 0 = "{random values}"
Step 5
Restore these modified registry values
Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MediaPlayer
- From: MP2.SaveDir = "%Program Files%\Windows Media Player"
To: MP2.SaveDir = ""%Program Files%\Windows Media Player""
- From: MP2.SaveDir = "%Program Files%\Windows Media Player"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
- From: userinit = "%System%\userinit.exe,%System%\twext.exe,"
To: userinit = ""%Windows%\system32\userinit.exe,""
- From: userinit = "%System%\userinit.exe,%System%\twext.exe,"
Step 6
Search and delete these components
- %User Profile%\HTML Help\hh.dat
- %System%\twext.exe
Step 7
Search and delete this folder
- %User Profile%\Microsoft\HTML Help
Step 8
Scan your computer with your Trend Micro product to delete files detected as TSPY_ZBOT.SMMB. 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 9
Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.
- %System%\twext.exe
Step 10
Restore these deleted registry keys/values 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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\MUILanguages
- FileVersions
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