TSPY_ZBOT.JWS
PWS:Win32/Zbot (Microsoft), Trojan-Spy.Win32.Zbot.ejqr (Kaspersky), Trojan.Gen (Symantec), PWS-Zbot.gen.sd (NAI), Troj/Zbot-CHB (Sophos), Trojan.Generic.KDV.679367 (FSecure), Trojan.Win32.Generic!BT (Sunbelt), W32/Trojan2.NSFD (Authentium), Trojan.Generic.KDV.679367 (Bitdefender), PUA.Win32.Packer.Armadillo-59 (Clamav) , W32/Zbot.EJQR!tr (Fortinet), W32/Trojan2.NSFD (exact) (Fprot), Trojan-Spy.Win32.Zbot (Ikarus), Win32/Spy.Zbot.AAO trojan (NOD32), Trojan W32/Troj_Generic.DBJSV (Norman), TrojanSpy.Zbot.ejqr (VBA32)
Windows 2000, Windows XP, Windows Server 2003
Threat Type: Spyware
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This spyware arrives as an attachment to email messages spammed by other malware/grayware or malicious users. It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
It creates folders where it drops its files. The dropped file is injected in all running processes.
It modifies the Internet Explorer Zone Settings.
TECHNICAL DETAILS
Arrival Details
This spyware arrives as an attachment to email messages spammed by other malware/grayware or malicious users.
It 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 a copy of itself in the following folders using different file names:
- %User Profile%\Application Data\{random folder1}\{random file name1}.exe
(Note: %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.)
It drops the following component file(s):
- %User Profile%\Application Data\{random folder2}\{random file name and extension2}
- %User Profile%\Application Data\{random folder3}\{random file name and extension3}
(Note: %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.)
It creates the following folders:
- %User Profile%\Application Data\{random folder1}
- %User Profile%\Application Data\{random folder2}
- %User Profile%\Application Data\{random folder3}
(Note: %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.)
The dropped file is injected in all running processes.
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 characters} = "%User Profile%\Application Data\{random folder1}\{random file name1}.exe"
Other System Modifications
This spyware 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 spyware modifies the Internet Explorer Zone Settings.
SOLUTION
Step 1
For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.
Step 2
Scan your computer with your Trend Micro product and note files detected as TSPY_ZBOT.JWS
Step 3
Restart in Safe Mode
Step 4
Search and delete these folders
- %User Profile%\Application Data\{random folder1}
- %User Profile%\Application Data\{random folder2}
- %User Profile%\Application Data\{random folder3}
Step 5
Delete the registry entry with an unknown data 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 characters} = "%User Profile%\Application Data\{random folder1}\{random file name1}.exe"
- {random characters} = "%User Profile%\Application Data\{random folder1}\{random file name1}.exe"
Step 6
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\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 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.JWS. 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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