TSPY_ZBOT.YYDAW
Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)
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.
It bypasses the Windows firewall. This allows the malware to perform its intended routine without being detected by an installed firewall.
It modifies the Internet Explorer Zone Settings.
It deletes the initially executed copy of itself.
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 non-malicious file:
- %Application Data%\{random folder 2}\{random filename}.{random extension}
- %Application Data%\Microsoft\Address Book\{user name}.wab
- %User Temp%\{random}.bat - It is used to delete its initially executed copy. This component is deleted after execution
(Note: %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.. %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 creates the following folders:
- %Application Data%\{random folder 1}
- %Application Data%\{random folder 2}
(Note: %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 adds the following mutexes to ensure that only one of its copies runs at any one time:
- Global\{GUID}
- Local\{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
{random filename}.exe = "%Application Data%\{random folder 1}\{random filename}.exe"
Other System Modifications
This spyware adds the following registry keys:
HKEY_CURRENT_USER\Software\Microsoft\
{random key name}
It modifies the following registry entries to disable the Windows Firewall settings:
HKEY_LOCAL_MACHINE\System\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\GloballyOpenPorts\
List
{port1}:UDP = "{port1}:UDP:*:Enabled:UDP {port1}"
HKEY_LOCAL_MACHINE\System\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\GloballyOpenPorts\
List
{port2}:TCP = "{port2}:TCP:*:Enabled:TCP {port2}"
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}nety.org/nano/pules.jpg - no longer available
Information Theft
This spyware s configuration file contains the following information:
- URLs where it downloads an updated copy of itself
- URL where it sends its gathered information
It gathers the following data:
- Bot ID
- 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/webhp
It deletes the initially executed copy of itself
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
Scan your computer with your Trend Micro product and note files detected as TSPY_ZBOT.YYDAW
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 filename}.exe = "%Application Data%\{random folder 1}\{random filename}.exe"
- {random filename}.exe = "%Application Data%\{random folder 1}\{random filename}.exe"
- In HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\GloballyOpenPorts\List
- {port1}:UDP = "{port1}:UDP:*:Enabled:UDP {port1}"
- {port1}:UDP = "{port1}:UDP:*:Enabled:UDP {port1}"
- In HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\GloballyOpenPorts\List
- {port2}:TCP = "{port2}:TCP:*:Enabled:TCP {port2}"
- {port2}:TCP = "{port2}:TCP:*:Enabled:TCP {port2}"
- 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"
- In HKEY_CURRENT_USER\Software\Microsoft\WAB\WAB4\Wab File Name
- (Default) = "%User Profile%\Application Data\Microsoft\Address Book\{user name}.wab"
- (Default) = "%User Profile%\Application Data\Microsoft\Address Book\{user name}.wab"
Step 6
Search and delete these folders
- %Application Data%\{random folder 1}
- %Application Data%\{random folder 2}
Step 7
Reset Internet privacy settings
Step 8
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TSPY_ZBOT.YYDAW. 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
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.
- In HKEY_CURRENT_USER\Software\Microsoft
- {random key name}
- {random key name}
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