TROJ_BHO.TT
TrojanDownloader:Win32/Renos.FS (Microsoft); generic!bg.fex (McAfee); Trojan.Dropper (Symantec); Trojan-Dropper.Win32.Agent.afwc (Kaspersky); Fraudtool.Win32.WinDefender2009 (v) (Sunbelt); Trojan.Dropper.SMN (FSecure)
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
286,727 bytes
EXE
No
05 Dec 2011
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 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\{14EAF723-CAAC-42CE-BA4D-F69DC3A4A838}
Other System Modifications
This Trojan adds the following registry keys:
HKEY_CURRENT_USER\Software\Microsoft\
Bind
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Browser Helper Objects
HKEY_CLASSES_ROOT\Klsm.1
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Klsm.1\CLSID
HKEY_CLASSES_ROOT\Klsm
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Klsm\CLSID
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Klsm\CurVer
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{14EAF723-CAAC-42CE-BA4D-F69DC3A4A838}
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{14EAF723-CAAC-42CE-BA4D-F69DC3A4A838}\ProgID
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{14EAF723-CAAC-42CE-BA4D-F69DC3A4A838}\VersionIndependentProgID
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{14EAF723-CAAC-42CE-BA4D-F69DC3A4A838}\Programmable
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{14EAF723-CAAC-42CE-BA4D-F69DC3A4A838}\InprocServer32
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{14EAF723-CAAC-42CE-BA4D-F69DC3A4A838}\TypeLib
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{A8954909-1F0F-41A5-A7FA-3B376D69E226}
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{A8954909-1F0F-41A5-A7FA-3B376D69E226}\1.0
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{A8954909-1F0F-41A5-A7FA-3B376D69E226}\1.0\
FLAGS
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{A8954909-1F0F-41A5-A7FA-3B376D69E226}\1.0\
0
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{A8954909-1F0F-41A5-A7FA-3B376D69E226}\1.0\
0\win32
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
TypeLib\{A8954909-1F0F-41A5-A7FA-3B376D69E226}\1.0\
HELPDIR
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{63F102EE-99D9-4B22-9072-BF4F5723CE69}
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{63F102EE-99D9-4B22-9072-BF4F5723CE69}\ProxyStubClsid
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{63F102EE-99D9-4B22-9072-BF4F5723CE69}\ProxyStubClsid32
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{63F102EE-99D9-4B22-9072-BF4F5723CE69}\TypeLib
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{111F9296-2B08-44B9-8D5E-BEAB867A0E2F}
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{111F9296-2B08-44B9-8D5E-BEAB867A0E2F}\ProxyStubClsid
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{111F9296-2B08-44B9-8D5E-BEAB867A0E2F}\ProxyStubClsid32
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{111F9296-2B08-44B9-8D5E-BEAB867A0E2F}\TypeLib
It adds the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{14EAF723-CAAC-42CE-BA4D-F69DC3A4A838}\InprocServer32
ThreadingModel = "Apartment"
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{63F102EE-99D9-4B22-9072-BF4F5723CE69}\TypeLib
Version = "1.0"
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
Interface\{111F9296-2B08-44B9-8D5E-BEAB867A0E2F}\TypeLib
Version = "1.0"
It modifies the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
DirectDraw\MostRecentApplication
Name = "iexplore.exe"
(Note: The default value data of the said registry entry is mshta.exe.)
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
DirectDraw\MostRecentApplication
ID = 4117b81
(Note: The default value data of the said registry entry is 41107b3f.)
Dropping Routine
This Trojan drops the following files:
- %System%\hhsa.dll
- %Windows%\ios.dat
- %System%\p.ico
- %Desktop%\SMS TRAP.url
- %Favorites%\SMS TRAP.url
- %Start Menu%\SMS TRAP.url
- %System%\sf.ico
- %Desktop%\Cheap Software.url
- %Favorites%\Cheap Software.url
- %Start Menu%\Cheap Software.url
- %System%\c.ico
- %Desktop%\VIP Casino.url
- %Favorites%\VIP Casino.url
- %Start Menu%\VIP Casino.url
- %System%\m.ico
- %Desktop%\Cheap Pharmacy Online.url
- %Favorites%\Cheap Pharmacy Online.url
- %Start Menu%\Cheap Pharmacy Online.url
- %System%\m3.ico
- %Desktop%\MP3 Download.url
- %Favorites%\MP3 Download.url
- %Start Menu%\MP3 Download.url
- %System%\s.ico
- %Desktop%\Search Online.url
- %Favorites%\Search Online.url
- %Start Menu%\Search Online.url
(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.. %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.. %Desktop% is the current user's desktop, which is usually C:\Windows\Profiles\{user name}\Desktop on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Desktop on Windows NT, and C:\Documents and Settings\{User Name}\Desktop on Windows 2000, XP, and Server 2003.. %Favorites% is the current user's Favorites folder, which is usually C:\Windows\Favorites on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Favorites on Windows NT, and C:\Documents and Settings\{user name}\Favorites on Windows 2000, XP, and Server 2003.. %Start Menu% is the current user's Start Menu folder, which is usually C:\Windows\Profiles\{user name}\Start Menu on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu on Windows NT and C:\Windows\Start Menu or C:\Documents and Settings\{User name}\Start Menu on Windows 2000, XP, and Server 2003.)
This report is generated via an automated analysis system.
SOLUTION
9.200
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
Close all opened browser windows
Step 3
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
- Bind
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer
- Browser Helper Objects
- In HKEY_CLASSES_ROOT
- Klsm.1
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Klsm.1
- CLSID
- In HKEY_CLASSES_ROOT
- Klsm
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Klsm
- CLSID
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Klsm
- CurVer
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID
- {14EAF723-CAAC-42CE-BA4D-F69DC3A4A838}
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{14EAF723-CAAC-42CE-BA4D-F69DC3A4A838}
- ProgID
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{14EAF723-CAAC-42CE-BA4D-F69DC3A4A838}
- VersionIndependentProgID
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{14EAF723-CAAC-42CE-BA4D-F69DC3A4A838}
- Programmable
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{14EAF723-CAAC-42CE-BA4D-F69DC3A4A838}
- InprocServer32
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{14EAF723-CAAC-42CE-BA4D-F69DC3A4A838}
- TypeLib
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib
- {A8954909-1F0F-41A5-A7FA-3B376D69E226}
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib\{A8954909-1F0F-41A5-A7FA-3B376D69E226}
- 1.0
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib\{A8954909-1F0F-41A5-A7FA-3B376D69E226}\1.0
- FLAGS
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib\{A8954909-1F0F-41A5-A7FA-3B376D69E226}\1.0
- 0
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib\{A8954909-1F0F-41A5-A7FA-3B376D69E226}\1.0\0
- win32
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\TypeLib\{A8954909-1F0F-41A5-A7FA-3B376D69E226}\1.0
- HELPDIR
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface
- {63F102EE-99D9-4B22-9072-BF4F5723CE69}
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{63F102EE-99D9-4B22-9072-BF4F5723CE69}
- ProxyStubClsid
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{63F102EE-99D9-4B22-9072-BF4F5723CE69}
- ProxyStubClsid32
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{63F102EE-99D9-4B22-9072-BF4F5723CE69}
- TypeLib
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface
- {111F9296-2B08-44B9-8D5E-BEAB867A0E2F}
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{111F9296-2B08-44B9-8D5E-BEAB867A0E2F}
- ProxyStubClsid
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{111F9296-2B08-44B9-8D5E-BEAB867A0E2F}
- ProxyStubClsid32
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{111F9296-2B08-44B9-8D5E-BEAB867A0E2F}
- TypeLib
Step 4
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\Classes\CLSID\{14EAF723-CAAC-42CE-BA4D-F69DC3A4A838}\InprocServer32
- ThreadingModel="Apartment"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{63F102EE-99D9-4B22-9072-BF4F5723CE69}\TypeLib
- Version="1.0"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Interface\{111F9296-2B08-44B9-8D5E-BEAB867A0E2F}\TypeLib
- Version="1.0"
Step 5
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\DirectDraw\MostRecentApplication
- From: Name="iexplore.exe"
To: Name=mshta.exe
- From: Name="iexplore.exe"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\DirectDraw\MostRecentApplication
- From: ID=4117b81
To: ID=41107b3f
- From: ID=4117b81
Step 6
Search and delete these files
- %System%\hhsa.dll
- %Windows%\ios.dat
- %System%\p.ico
- %Desktop%\SMS TRAP.url
- %Favorites%\SMS TRAP.url
- %Start Menu%\SMS TRAP.url
- %System%\sf.ico
- %Desktop%\Cheap Software.url
- %Favorites%\Cheap Software.url
- %Start Menu%\Cheap Software.url
- %System%\c.ico
- %Desktop%\VIP Casino.url
- %Favorites%\VIP Casino.url
- %Start Menu%\VIP Casino.url
- %System%\m.ico
- %Desktop%\Cheap Pharmacy Online.url
- %Favorites%\Cheap Pharmacy Online.url
- %Start Menu%\Cheap Pharmacy Online.url
- %System%\m3.ico
- %Desktop%\MP3 Download.url
- %Favorites%\MP3 Download.url
- %Start Menu%\MP3 Download.url
- %System%\s.ico
- %Desktop%\Search Online.url
- %Favorites%\Search Online.url
- %Start Menu%\Search Online.url
Step 7
Scan your computer with your Trend Micro product to delete files detected as TROJ_BHO.TT. 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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