This worm arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
It lowers the security setting of Internet Explorer.
It attempts to steal sensitive online banking information, such as user names and passwords. This routine risks the exposure of the user's account information, which may then lead to the unauthorized use of the stolen data.
Arrival Details
This worm 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 worm drops the following copies of itself into the affected system and executes them:
- %Application Data%\{Random Folder 1}\{Random Filename}.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 component file(s):
- %Application Data%\{Random Folder 2}\{Random Filename and Extension}
- %Application Data%\{Random Folder 3}\{Random Filename and 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.)
Autostart Technique
This worm adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{Random} = "%Application Data%"\{Random Folder 1}\{Random Filename}.exe
Other System Modifications
This worm creates the following registry entry(ies) to bypass Windows Firewall:
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 worm lowers the security setting of Internet Explorer.
Download Routine
This worm connects to the following website(s) to download and execute a malicious file:
- http://{BLOCKED}vers.ru/sexy/files/build.exe
Information Theft
This worm attempts to steal sensitive online banking information, such as user names and passwords. This routine risks the exposure of the user's account information, which may then lead to the unauthorized use of the stolen data.
Its configuration file contains the following information:
- http://{BLOCKED}ionhunter.ru/sexy/file.php
- http://{BLOCKED}funsite.ru/sexy/file.php
Other Details
The configuration file may contain URLs that it access to download an updated copy of itself and to send its gathered information.
NOTES:
It then drops a .LNK file (Shortcut file) on the removable drive, which points to the path and filename of the dropped copy of the malware on the removable drive.
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
Restart in Safe Mode
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To restart in Safe Mode:
• For Windows 2000 users
- Restart your computer.
- Press F8 when you see the Starting Windows bar at the bottom of the screen.
- Choose the Safe Mode option from the Windows Advanced Options menu then press Enter.
• For Windows XP users
- Restart your computer.
- Press F8 after the Power-On Self Test (POST) routine is done. If the Windows Advanced Options menu does not appear, try restarting then pressing F8 several times when the POST screen appears.
- Choose the Safe Mode option from the Windows Advanced Options menu then press Enter.
• For Windows Server 2003 users
- Restart your computer.
- Press F8 after Windows starts up. If the Windows Advanced Options menu does not appear, try restarting again and pressing F8 several times afterward.
- On the Windows Advanced Option menu, use the arrow keys to select Safe Mode then press Enter.
• For Windows Vista and Windows 7 users
- Restart your computer.
- Press F8 after the Power-On Self Test (POST) routine is done. If the Advanced Boot Options menu does not appear, try restarting and then pressing F8 several times after the POST screen is displayed.
- On the Advanced Boot Options menu, use the arrow keys to select the Safe Mode option, and then press Enter.
Step 3
Delete this registry value
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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} = "%Application Data%"\{Random Folder 1}\{Random Filename}.exe
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
- "%Windows%"\explorer.exe = "%Windows%"\explorer.exe:*:Enabled:Windows Explorer
To delete the registry value this malware created:
- Open Registry Editor. To do this, click Start>Run, type regedit in the text box provided, then press Enter.
- In the left panel of the Registry Editor window, double-click the following:
HKEY_CURRENT_USER>Software>Microsoft>Windows>CurrentVersion>Run - In the right panel, locate and delete the entry:
{Random} = "%Application Data%"\{Random Folder 1}\{Random Filename}.exe - In the left panel of the Registry Editor window, double-click the following:
HKEY_LOCAL_MACHINE>SYSTEM>CurrentControlSet>Services>SharedAccess>Parameters>FirewallPolicy>StandardProfile>AuthorizedApplications>List - In the right panel, locate and delete the entry:
"%Windows%"\explorer.exe = "%Windows%"\explorer.exe:*:Enabled:Windows Explorer - Close Registry Editor.
Step 4
Search and delete these folders
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Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden folders in the search result.
- %Application Data%\{Random Folder 1}
- %Application Data%\{Random Folder 2}
- %Application Data%\{Random Folder 3}
To delete folders created that this malware/grayware created:
For Windows 2000, Windows XP, and Windows Server 2003:
- Right-click Start then click Search....
- In the left panel, click All Files.
- In the Named input box, type any of the following:
- %Application Data%\{Random Folder 1}
- %Application Data%\{Random Folder 2}
- %Application Data%\{Random Folder 3}
- In the Look In drop-down list, select My Computer then press Enter.
- Once located, select the file then press SHIFT+DELETE to delete it.
- Repeat steps above for the remaining folders.
For Windows Vista and Windows 7:
- Click Start>Computer.
- In the Search Computer input box, type any of the following:
- %Application Data%\{Random Folder 1}
- %Application Data%\{Random Folder 2}
- %Application Data%\{Random Folder 3}
- Once located, select the file then press SHIFT+DELETE to delete it.
- Repeat steps above for the remaining folders.
*Note: Read the following Microsoft page if these steps do not work on Windows 7.
Step 5
Reset Internet security settings
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To reset Internet security settings:
- Close all Internet browser windows.
- Open Control Panel. To do this:
• On Windows 2000
Click Start>Settings>Control Panel
• On Windows XP, Server 2003, Vista, and 7
Click Start>Control Panel - Double-click Internet Options.
- In the Internet Properties window, click the Security tab.
- For each Web content zone, click on the Default Level button to set each zone to the default setting.
- Click OK.
Step 6
Scan your computer with your Trend Micro product to delete files detected as WORM_ZBOT.GJ. 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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