TSPY_ZBOT.SMOA
Trojan-Spy.Win32.Zbot.vdav (Kaspersky)
Windows
![](/vinfo/imgFiles/legend.jpg)
Threat Type: Spyware
Destructiveness: No
Encrypted: Yes
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.
It is injected into all running processes to remain memory resident.
It modifies the Internet Explorer Zone Settings.
As of this writing, the said sites are inaccessible.
It steals certain information from the system and/or the user.
It deletes itself after execution.
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 drops the following copies of itself into the affected system:
- %Application Data%\{random folder 1}\{random filename 1}.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.)
It drops and executes the following files:
- %User Temp%\tmp{random}.bat ← use to delete its initially executed copy and this component file itself
(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp 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.)
It drops the following non-malicious files:
- %Application Data%\{random folder 2}\{random file name 2}.tmp
- %Application Data%\{random folder 2}\{random file name 2}.{random extension}
(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.)
It creates the following folders:
- %Application Data%\{random folder 1}
- %Application Data%\{random folder 2}
(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.)
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:
- Local\{GUID}
- Global\{GUID}
It injects codes into the following process(es):
- explorer.exe
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 filename 1}.exe "
Other System Modifications
This spyware adds the following registry keys:
HKEY_CURRENT_USER\Software\Microsoft\
{random key}
It adds the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
{random key}
{random} = "{random values}"
HKEY_CURRENT_USER\Software\Microsoft\
WAB\WAB4
FirstRun = "1"
HKEY_CURRENT_USER\Software\Microsoft\
WAB\WAB4
OlkContactRefresh = "0"
HKEY_CURRENT_USER\Software\Microsoft\
WAB\WAB4
OlkFolderRefresh = "0"
HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Privacy
CleanCookies = "0"
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
%Windows%\EXPLORER.EXE = %Windows%\EXPLORER.EXE:*:Enabled:Windows Explorer
Web Browser Home Page and Search Page Modification
This spyware modifies the Internet Explorer Zone Settings.
Download Routine
This spyware connects to the following URL(s) to download its configuration file:
- http://{BLOCKED}.{BLOCKED}.120.143/~matlab/js/config.bin
As of this writing, the said sites are inaccessible.
Information Theft
This spyware steals the following information:
- Data on cookie files (URLs)
- Email-related information such as account names, email addresses, passwords, server data, and server port
- Email information stored in the user’s Windows Address Book (WAB) file
- Online banking credentials
- Personal digital cerificate
Its configuration file contains the following information:
- URLs where it downloads an updated copy of itself
- URLs where it sends its gathered information
- URLs of its target online banking and finance-related sites from where it steals the information
Other Details
This spyware deletes itself after execution.
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
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
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\Windows\CurrentVersion\Run
- {GUID} = "%Application Data%\{random folder 1}\{random filename 1}.exe "
- {GUID} = "%Application Data%\{random folder 1}\{random filename 1}.exe "
- In HKEY_CURRENT_USER\Software\Microsoft\WAB\WAB4
- FirstRun = "1"
- FirstRun = "1"
- In HKEY_CURRENT_USER\Software\Microsoft\WAB\WAB4
- OlkContactRefresh = "0"
- OlkContactRefresh = "0"
- In HKEY_CURRENT_USER\Software\Microsoft\WAB\WAB4
- OlkFolderRefresh = "0"
- OlkFolderRefresh = "0"
- In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Privacy
- CleanCookies = "0"
- CleanCookies = "0"
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
- %Windows%\EXPLORER.EXE = %Windows%\EXPLORER.EXE:*:Enabled:Windows Explorer
- %Windows%\EXPLORER.EXE = %Windows%\EXPLORER.EXE:*:Enabled:Windows Explorer
Step 5
Reset Internet security settings
Step 6
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TSPY_ZBOT.SMOA. 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 7
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}
- HKEY_CURRENT_USER\Software\Microsoft\{random key}
- {random} = "{random values}"
- %Application Data%\{random folder 1}
- %Application Data%\{random folder 2}
- %Application Data%\{random folder 2}\{random file name 2}.tmp
- %Application Data%\{random folder 2}\{random file name 2}.{random extension}
- {random} = "{random values}"
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