TSPY_ZBOT.SMWE
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 as an attachment to email messages spammed by other malware/grayware or malicious users. It may be downloaded by other malware/grayware/spyware from remote sites. It may be dropped by other malware. It may be unknowingly downloaded by a user while visiting malicious websites.
It is injected into all running processes to remain memory resident.
As of this writing, the said sites are inaccessible.
TECHNICAL DETAILS
Arrival Details
This spyware arrives as an attachment to email messages spammed by other malware/grayware or malicious users.
It may be downloaded by other malware/grayware/spyware from remote sites.
It may be dropped by other malware.
It may be unknowingly downloaded by a user while visiting malicious websites.
Installation
This spyware drops the following files:
- %System%\twain_32\local.ds
- %System%\twain_32\user.ds
(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)
It drops the following copies of itself into the affected system:
- %System%\twext.exe
(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)
It creates the following folders:
- %System%\twain_32
(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)
It is injected into all running processes to remain memory resident.
It adds the following mutexes to ensure that only one of its copies runs at any one time:
- __SYSTEM__7F4523E5__
Autostart Technique
This spyware modifies the following registry entry(ies) to enable its automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
Userinit = %System%\userinit.exe,%System%\twext.exe,
Other System Modifications
This spyware adds the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Network
UID = {computer name}
Download Routine
This spyware connects to the following URL(s) to download its configuration file:
- http://{BLOCKED}.{BLOCKED}.233.115/ukk/cfg.bin
As of this writing, the said sites are inaccessible.
Information Theft
The downloaded file contains information where the malware can download an updated copy of itself, and where to send its stolen data.
SOLUTION
Step 1
For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.
Step 2
Restart in Safe Mode
Step 3
Restore this modified 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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
- From: Userinit = %System%\userinit.exe,%System%\twext.exe,
To: Userinit = %System%\userinit.exe,
- From: Userinit = %System%\userinit.exe,%System%\twext.exe,
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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Network
- UID = "{computer name}"
- UID = "{computer name}"
Step 5
Search and delete this file
Step 6
Search and delete these folders
Step 7
Scan your computer with your Trend Micro product to delete files detected as TSPY_ZBOT.SMWE. 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.
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