TROJ_VUNDO.SMZ
Worm:Win32/Vundo.A (Microsoft); Vundo.gen.bf (McAfee); Trojan.Vundo (Symantec); Trojan-Downloader.Win32.Agent.bqxc (Kaspersky); Trojan.Win32.Vundo.gen.bd (v) (Sunbelt)
Windows 2000, Windows XP, Windows Server 2003
Threat Type: Trojan
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
TECHNICAL DETAILS
Arrival Details
This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
Autostart Technique
This Trojan adds the following registry entries to enable its automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
jawisesoza = "Rundll32.exe %System%\kafadogi.dll,s"
It registers itself as a BHO to ensure its automatic execution every time Internet Explorer is used by adding the following registry keys:
HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Browser Helper Objects\{5de68c3b-dd31-47f0-8d19-cb1aed401731}
Other System Modifications
This Trojan deletes the following files:
- %System%\fosowefe.dll
- %System%\borazufu.dll
- %System%\tupurevo.dll
- %System%\wisebiga.dll
(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)
It adds the following registry keys:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
sezavime
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{5de68c3b-dd31-47f0-8d19-cb1aed401731}\InprocServer32
HKEY_CLASSES_ROOT\CLSID\{5de68c3b-dd31-47f0-8d19-cb1aed401731}
It adds the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
sezavime
savemimi = "{random values}"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Windows
LoadAppInit_DLLs = "1"
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{5de68c3b-dd31-47f0-8d19-cb1aed401731}\InprocServer32
ThreadingModel = "Both"
It modifies the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Windows
AppInit_DLLs = "%System%\hufufoga.dll"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Control\Lsa
Notification Packages = "scecli,%System%\hufufoga.dll"
(Note: The default value data of the said registry entry is {random values}.)
It deletes the following registry keys:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Ext\
Settings\{5de68c3b-dd31-47f0-8d19-cb1aed401731}
This report is generated via an automated analysis system.
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
Restart in Safe Mode
Step 3
Close all opened browser windows
Step 4
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_LOCAL_MACHINE\SOFTWARE\Microsoft
- sezavime
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{5de68c3b-dd31-47f0-8d19-cb1aed401731}
- InprocServer32
- In HKEY_CLASSES_ROOT\CLSID
- {5de68c3b-dd31-47f0-8d19-cb1aed401731}
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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
- jawisesoza = "Rundll32.exe %System%\kafadogi.dll,s"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\sezavime
- savemimi = "{random values}"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Windows
- LoadAppInit_DLLs = "1"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{5de68c3b-dd31-47f0-8d19-cb1aed401731}\InprocServer32
- ThreadingModel = "Both"
Step 6
Restore this modified 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\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Windows
- AppInit_DLLs = "%System%\hufufoga.dll"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\Lsa
- From: Notification Packages = "scecli,%System%\hufufoga.dll"
To: Notification Packages = ""{random values}""
- From: Notification Packages = "scecli,%System%\hufufoga.dll"
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_VUNDO.SMZ. 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 8
Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.
- %System%\fosowefe.dll
- %System%\borazufu.dll
- %System%\tupurevo.dll
- %System%\wisebiga.dll
Step 9
Restore these deleted registry keys/values from backup
*Note: Only Microsoft-related keys/values will be restored. If the malware/grayware also deleted registry keys/values related to programs that are not from Microsoft, please reinstall those programs on your computer.
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Ext\Settings
- {5de68c3b-dd31-47f0-8d19-cb1aed401731}
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