TSPY_ZBOT.EPK
VirTool:Win32/CeeInject.EF (Microsoft), Trojan.Zbot!gen35 (Norton), PWS-Zbot.gen.als (NAI), Mal/Katusha-J, Mal/Katusha-J (Sophos), LooksLike.Win32.ZboCheman.a (v) (Sunbelt), Gen:Heur.PIF.4 (BitDefender), W32/Yakes.AP!tr (Fortinet), Trojan-Ransom.Win32.PornoAsset (Ikarus)
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 modifies Internet Explorer security settings. This puts the affected computer at greater risk, as it allows malicious URLs to be accessed by the computer.
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_NAME1}\{MALWARE_FILE_NAME}.exe
(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 drops the following files:
- %Application Data%\Microsoft\Address Book\winxp.wab
- %Application Data%\{RANDOM_FOLDER_NAME2}\{RANDOM_FILE_NAME}.{RANDOM_FILE_EXTENSION}
(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 creates the following folders:
- %Application Data%\{RANDOM_FOLDER_NAME1}
- %Application Data%\{RANDOM_FOLDER_NAME2}
- %Application Data%\Microsoft\Address Book
(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.)
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_CLSID} = "%Application Data%\{RANDOM_FOLDER_NAME}\{MALWARE_FILE_NAME}.exe"
Other System Modifications
This spyware adds the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
WAB
HKEY_CURRENT_USER\Software\Microsoft\
{RANDOM_VALUES}
It creates the following registry entry(ies) to bypass Windows Firewall:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\GloballyOpenPorts\
List
{RANDOM_PORT_NUMBER}:TCP = "{RANDOM_PORT_NUMBER}:TCP:*:Enabled:TCP {RANDOM_PORT_NUMBER}"
Web Browser Home Page and Search Page Modification
This spyware modifies Internet Explorer zone settings.
Other Details
This spyware connects to the following possibly malicious URL:
- http://{pseudorandom_domain_name}.ru/{random}.php
- http://{pseudorandom_domain_name}.com/{random}.php
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
Scan your computer with your Trend Micro product and note files detected as TSPY_ZBOT.EPK
Step 3
Restart in Safe Mode
Step 4
Search and delete these folders
- %Application Data%\{RANDOM_FOLDER_NAME1}
- %Application Data%\{RANDOM_FOLDER_NAME2}
- %Application Data%\Microsoft\Address Book
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_CLSID} = "%Application Data%\{RANDOM_FOLDER_NAME}\{MALWARE_FILE_NAME}.exe"
- {RANDOM_CLSID} = "%Application Data%\{RANDOM_FOLDER_NAME}\{MALWARE_FILE_NAME}.exe"
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\GloballyOpenPorts\List
- {RANDOM_PORT_NUMBER}:TCP = "{RANDOM_PORT_NUMBER}:TCP:*:Enabled:TCP {RANDOM_PORT_NUMBER}"
- {RANDOM_PORT_NUMBER}:TCP = "{RANDOM_PORT_NUMBER}:TCP:*:Enabled:TCP {RANDOM_PORT_NUMBER}"
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
- In HKEY_CURRENT_USER\Software\Microsoft
- {RANDOM_VALUES}
- {RANDOM_VALUES}
Step 7
Reset Internet security settings
Step 8
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TSPY_ZBOT.EPK. 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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