TROJ_COSMU.SMUM1
Trojan:Win32/Sisron (Microsoft); Trojan.Gen (Symantec); Trojan.Win32.Cosmu.acij (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt); Trojan.Generic.4856748 (FSecure)
Windows 2000, Windows XP, Windows Server 2003
![](/vinfo/imgFiles/legend.jpg)
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.
Installation
This Trojan drops the following copies of itself into the affected system:
- %System%\syscfgwin.exe
- %System%\sqlpptpdhcp.exe
- %System%\infsvccpl.exe
- %System%\syspdbsrv.exe
- %System%\urludfdsp.exe
- %System%\objnetobj.exe
(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.)
Autostart Technique
This Trojan adds the following registry entries to enable its automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{22d7f312-b0f6-11d2-94ab-0080c33c7e95}
StubPath = "rundll32.exe %System%\themeuichk.dll,ThemesSetupInstallCheck"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{22d7f312-b0f6-11d2-94ab-0080c33c7e95}
IconsBinary = "{random values}"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{22d7f312-b0f6-11d2-94ab-0080c33c7e95}
Version = "1,1,1,2"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{22d7f312-b0f6-11d2-94ab-0080c33c7e95}
ComponentID = "DOTNETFRAMEWORKS"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{22d7f312-b0f6-11d2-94ab-0080c33c7e95}
DontAsk = "2"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{22d7f312-b0f6-11d2-94ab-0080c33c7e95}
IsInstalled = "1"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
recovery = "%System%\urludfdsp.exe"
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\{18DF081C-E8AD-4283-A596-FA578C2EBDC3}
Other System Modifications
This Trojan deletes the following files:
- %System%\syscfgwin.exe
- %System%\syscfgwin.exejdnxq3
- %System%\sqlpptpdhcp.exe
- %System%\sqlpptpdhcp.exevxg3ut
- %System%\infsvccpl.exe
- %System%\infsvccpl.exeitkesj
- %System%\syspdbsrv.exe
- %System%\syspdbsrv.exebm2c0w
- %System%\urludfdsp.exe
- %System%\urludfdsp.exejen1ql
- %System%\fsmsfw.ocx
- %System%\fsmsfw.ocxw5zxce
- %System%\objnetobj.exe
- %System%\objnetobj.exe2p04rw
(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\Google\
SpoolCDS
HKEY_CURRENT_USER\Software\Mozilla\
Firefox
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{22d7f312-b0f6-11d2-94ab-0080c33c7e95}
HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer\Run
HKEY_LOCAL_MACHINE\Software\Adobe\
CommonFiles
HKEY_CLASSES_ROOT\CLSID\{18DF081C-E8AD-4283-A596-FA578C2EBDC3}
HKEY_CLASSES_ROOT\CLSID\{18DF081C-E8AD-4283-A596-FA578C2EBDC3}\
InprocServer32
HKEY_CLASSES_ROOT\CLSID\{18DF081C-E8AD-4283-A596-FA578C2EBDC3}\
ProgID
HKEY_CLASSES_ROOT\CLSID\{18DF081C-E8AD-4283-A596-FA578C2EBDC3}\
VersionIndependentProgID
HKEY_CURRENT_USER\Software\Microsoft\
Multimedia\DrawDib
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Control\MediaResources\msvideo
It adds the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Google\
SpoolCDS
SpoolManager = "%System%\syscfgwin.exe"
HKEY_CURRENT_USER\Software\Mozilla\
Firefox
JavaRTE = "{random values}"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
Explorer\Run
recovery = "%System%\urludfdsp.exe"
HKEY_LOCAL_MACHINE\SOFTWARE\Adobe\
CommonFiles
IconsStorage0 = "{random values}"
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{18DF081C-E8AD-4283-A596-FA578C2EBDC3}\InprocServer32
ThreadingModel = "Apartment"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Browser Helper Objects\{18DF081C-E8AD-4283-A596-FA578C2EBDC3}
NoExplorer = "1"
HKEY_CURRENT_USER\Software\Microsoft\
Windows NT\CurrentVersion
SerialIID = "{random values}"
HKEY_CURRENT_USER\Software\Microsoft\
Multimedia\DrawDib
vga.drv 1024x768x32(BGR 0) = "31,31,31,31"
Dropping Routine
This Trojan drops the following files:
- %User Temp%\1.tmp
- %User Temp%\2.tmp
- %User Temp%\3.tmp
- %User Temp%\4.tmp
- %User Temp%\5.tmp
- %System%\fsmsfw.ocx
(Note: %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.. %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.)
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\Google
- SpoolCDS
- In HKEY_CURRENT_USER\Software\Mozilla
- Firefox
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Active Setup\Installed Components
- {22d7f312-b0f6-11d2-94ab-0080c33c7e95}
- In HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
- Run
- In HKEY_LOCAL_MACHINE\Software\Adobe
- CommonFiles
- In HKEY_CLASSES_ROOT\CLSID
- {18DF081C-E8AD-4283-A596-FA578C2EBDC3}
- In HKEY_CLASSES_ROOT\CLSID\{18DF081C-E8AD-4283-A596-FA578C2EBDC3}
- InprocServer32
- In HKEY_CLASSES_ROOT\CLSID\{18DF081C-E8AD-4283-A596-FA578C2EBDC3}
- ProgID
- In HKEY_CLASSES_ROOT\CLSID\{18DF081C-E8AD-4283-A596-FA578C2EBDC3}
- VersionIndependentProgID
- In HKEY_CURRENT_USER\Software\Microsoft\Multimedia
- DrawDib
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\MediaResources
- msvideo
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\Active Setup\Installed Components\{22d7f312-b0f6-11d2-94ab-0080c33c7e95}
- StubPath = "rundll32.exe %System%\themeuichk.dll,ThemesSetupInstallCheck"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Active Setup\Installed Components\{22d7f312-b0f6-11d2-94ab-0080c33c7e95}
- IconsBinary = "{random values}"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Active Setup\Installed Components\{22d7f312-b0f6-11d2-94ab-0080c33c7e95}
- Version = "1,1,1,2"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Active Setup\Installed Components\{22d7f312-b0f6-11d2-94ab-0080c33c7e95}
- ComponentID = "DOTNETFRAMEWORKS"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Active Setup\Installed Components\{22d7f312-b0f6-11d2-94ab-0080c33c7e95}
- DontAsk = "2"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Active Setup\Installed Components\{22d7f312-b0f6-11d2-94ab-0080c33c7e95}
- IsInstalled = "1"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
- recovery = "%System%\urludfdsp.exe"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Google\SpoolCDS
- SpoolManager = "%System%\syscfgwin.exe"
- In HKEY_CURRENT_USER\Software\Mozilla\Firefox
- JavaRTE = "{random values}"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\Explorer\Run
- recovery = "%System%\urludfdsp.exe"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Adobe\CommonFiles
- IconsStorage0 = "{random values}"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{18DF081C-E8AD-4283-A596-FA578C2EBDC3}\InprocServer32
- ThreadingModel = "Apartment"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Browser Helper Objects\{18DF081C-E8AD-4283-A596-FA578C2EBDC3}
- NoExplorer = "1"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion
- SerialIID = "{random values}"
- In HKEY_CURRENT_USER\Software\Microsoft\Multimedia\DrawDib
- vga.drv 1024x768x32(BGR 0) = "31,31,31,31"
Step 6
Search and delete these files
- %User Temp%\1.tmp
- %User Temp%\2.tmp
- %User Temp%\3.tmp
- %User Temp%\4.tmp
- %User Temp%\5.tmp
- %System%\fsmsfw.ocx
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_COSMU.SMUM1. 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%\syscfgwin.exe
- %System%\syscfgwin.exejdnxq3
- %System%\sqlpptpdhcp.exe
- %System%\sqlpptpdhcp.exevxg3ut
- %System%\infsvccpl.exe
- %System%\infsvccpl.exeitkesj
- %System%\syspdbsrv.exe
- %System%\syspdbsrv.exebm2c0w
- %System%\urludfdsp.exe
- %System%\urludfdsp.exejen1ql
- %System%\fsmsfw.ocx
- %System%\fsmsfw.ocxw5zxce
- %System%\objnetobj.exe
- %System%\objnetobj.exe2p04rw
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