TSPY_ZBOT.YVAGE
Trojan-Spy.Win32.Zbot.tnbl (Kaspersky_
Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)
![](/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 Internet Explorer security settings. This puts the affected computer at greater risk, as it allows malicious URLs to be accessed by the computer.
It gathers certain information on the affected computer.
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 and executes them:
- %User Temp%\{random folder 1}\{random file name 1}.exe
(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)
It drops the following component file(s):
- %System%\drivers\{random file name 2}.sys - detected as RTKT_NECURS.YVAGE
(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)
It drops the following non-malicious files:
- %User Temp%\{random file name 3}.bat - used to delete the executed copy
- %Application Data%\Microsoft\Address Book\{user name}.wab
- %Application Data%\Microsoft\Address Book\{user name}.wab~
- %Application Data%\{random file name 2}.{random extension}
(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.. %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.)
It creates the following folders:
- %User Temp%\{random folder 1}
- %Application Data%\Microsoft\Address Book
(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.. %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.)
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:
- Global\{GUID}
- Local\{GUID}
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
{random file name 1} = "%User Temp%\{random folder 1}\{random file name 1}.exe"
Other System Modifications
This spyware adds the following registry keys:
HKEY_CURRENT_USER\Software\{random key}
HKEY_CURRENT_USER\Software\Microsoft\
WAB
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\{random key}
{random} = "{random}"
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"
It creates the following registry entry(ies) to bypass Windows Firewall:
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile
DisableNotifications = 1
(Note: The default value data of the said registry entry is "0".)
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\GloballyOpenPorts\
List
{random port 1}:UDP = "{random port 1}:UDP:*:Enabled:UDP {random port 1}"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\GloballyOpenPorts\
List
{random port 2}:TCP = "{random port 2}:TCP:*:Enabled:TCP {random port 2}"
Web Browser Home Page and Search Page Modification
This spyware modifies Internet Explorer zone settings.
Download Routine
This spyware connects to the following URL(s) to download its configuration file:
- http://{random URL}
Information Theft
This spyware gathers the following information on the affected computer:
- 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
Other Details
This spyware connects to the following URL(s) to check for an Internet connection:
- http://www.google.com
It deletes itself after execution.
The configuration file may contain URLs that it access to download an updated copy of itself and to send its gathered information.
NOTES:
It may also gather the following information from the affected system:
- 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
The configuration file may contain URLs where it downloads an updated copy of itself and sends its gathered information. It may also contain URLs of its target online banking and finance-related sites from where it steals the information.
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
Remove grayware/spyware files dropped/downloaded by TSPY_ZBOT.YVAGE
- RTKT_NECURS.YVAGE
Step 4
Restart in Safe Mode
Step 5
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
- {random file name 1} = "%User Temp%\{random folder 1}\{random file name 1}.exe"
- {random file name 1} = "%User Temp%\{random folder 1}\{random file name 1}.exe"
Step 6
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
- WAB
- WAB
Step 7
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\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\GloballyOpenPorts\List
- {random port 1}:UDP = "{random port 1}:UDP:*:Enabled:UDP {random port 1}"
- {random port 1}:UDP = "{random port 1}:UDP:*:Enabled:UDP {random port 1}"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\GloballyOpenPorts\List
- {random port 2}:TCP = "{random port 2}:TCP:*:Enabled:TCP {random port 2}"
- {random port 2}:TCP = "{random port 2}:TCP:*:Enabled:TCP {random port 2}"
Step 8
Restore this modified registry value
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\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile
- From: DisableNotifications = "1"
To: DisableNotifications = "0"
- From: DisableNotifications = "1"
Step 9
Search and delete these folders
- %Application Data%\Microsoft\Address Book
Step 10
Search and delete these files
- %User Temp%\{random file name 3}.bat
- %Application Data%\{random file name 2}.{random extension}
Step 11
Reset Internet security settings
Step 12
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TSPY_ZBOT.YVAGE. 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 13
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\{random key}
Step 14
Scan your computer with your Trend Micro product to delete files detected as TSPY_ZBOT.YVAGE. 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.
Did this description help? Tell us how we did.