TROJ_AGENT_0000176.TOMA
Trojan:Win32/Linkoptimizer (Microsoft); Spy-Agent.bf.dldr (McAfee); Trojan.Linkoptimizer (Symantec); PAK:UPX (Kaspersky); Trojan.LinkOptimizer (Sunbelt)
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.
It deletes itself after execution.
TECHNICAL DETAILS
193,024 bytes
EXE
No
31 Oct 2012
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\{E281853C-F457-3527-B294-35A4E6EF76E2}
Other System Modifications
This Trojan deletes the following files:
- %Temp%\1.tmp
- %Temp%\2.tmp
- %Program Files%\Common Files\Adobe\Acrobat\ActiveX\AcroIEHelperShim.dll
(Note: %Temp% is the Windows Temporary folder, which is usually C:\Windows\Temp or C:\WINNT\Temp.. %Program Files% is the default Program Files folder, usually C:\Program Files.)
It adds the following registry keys:
HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
{8B76C8E9-EB94-A62E-5762-C7D2577E3D0E}
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{E281853C-F457-3527-B294-35A4E6EF76E2}
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{E43E4DE6-3F2A-DABA-82DF-3A3B59484001}
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{E281853C-F457-3527-B294-35A4E6EF76E2}\InprocServer32
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{E43E4DE6-3F2A-DABA-82DF-3A3B59484001}\InprocServer32
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
hkylj
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
hkylj\{E43E4DE6-3F2A-DABA-82DF-3A3B59484001}
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\URLSearchHooks
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
nelae
HKEY_CLASSES_ROOT\CLSID\{4C7E5898-C71D-8B0B-A0F8-00D06AFEBEE6}
HKEY_CLASSES_ROOT\CLSID\{4C7E5898-C71D-8B0B-A0F8-00D06AFEBEE6}\
InprocServer32
It adds the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
{8B76C8E9-EB94-A62E-5762-C7D2577E3D0E}
DisplayName = "ConnectionKnight"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
{8B76C8E9-EB94-A62E-5762-C7D2577E3D0E}
UninstallString = "{random characters}"
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{E281853C-F457-3527-B294-35A4E6EF76E2}\InprocServer32
ThreadingModel = "Apartment"
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{E43E4DE6-3F2A-DABA-82DF-3A3B59484001}\InprocServer32
ThreadingModel = "Apartment"
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{4C7E5898-C71D-8B0B-A0F8-00D06AFEBEE6}\InprocServer32
ThreadingModel = "Apartment"
It deletes the following registry keys:
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{18DF081C-E8AD-4283-A596-FA578C2EBDC3}\InprocServer32
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{18DF081C-E8AD-4283-A596-FA578C2EBDC3}\ProgID
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{18DF081C-E8AD-4283-A596-FA578C2EBDC3}\Programmable
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{18DF081C-E8AD-4283-A596-FA578C2EBDC3}\TypeLib
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{18DF081C-E8AD-4283-A596-FA578C2EBDC3}\VersionIndependentProgID
HKEY_CLASSES_ROOT\CLSID\{18DF081C-E8AD-4283-A596-FA578C2EBDC3}
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Browser Helper Objects\{18DF081C-E8AD-4283-A596-FA578C2EBDC3}
HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Internet Explorer\URLSearchHooks
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Discardable\PostSetup\Component Categories\
{00021493-0000-0000-C000-000000000046}\Enum
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Discardable\PostSetup\Component Categories\
{00021494-0000-0000-C000-000000000046}\Enum
Dropping Routine
This Trojan drops the following files:
- %Windows%\qnqsp1.dll
- %Program Files%\Common Files\Adobe\Acrobat\ActiveX\AcroIEHelperShim.dll.$$$
(Note: %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.. %Program Files% is the default Program Files folder, usually C:\Program Files.)
Other Details
This Trojan deletes itself after execution.
This report is generated via an automated analysis system.
SOLUTION
9.300
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_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Uninstall
- {8B76C8E9-EB94-A62E-5762-C7D2577E3D0E}
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID
- {E281853C-F457-3527-B294-35A4E6EF76E2}
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID
- {E43E4DE6-3F2A-DABA-82DF-3A3B59484001}
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{E281853C-F457-3527-B294-35A4E6EF76E2}
- InprocServer32
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{E43E4DE6-3F2A-DABA-82DF-3A3B59484001}
- InprocServer32
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft
- hkylj
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\hkylj
- {E43E4DE6-3F2A-DABA-82DF-3A3B59484001}
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer
- URLSearchHooks
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft
- nelae
- In HKEY_CLASSES_ROOT\CLSID
- {4C7E5898-C71D-8B0B-A0F8-00D06AFEBEE6}
- In HKEY_CLASSES_ROOT\CLSID\{4C7E5898-C71D-8B0B-A0F8-00D06AFEBEE6}
- InprocServer32
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\Microsoft\Windows\CurrentVersion\Uninstall\{8B76C8E9-EB94-A62E-5762-C7D2577E3D0E}
- DisplayName = "ConnectionKnight"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\{8B76C8E9-EB94-A62E-5762-C7D2577E3D0E}
- UninstallString = "{random characters}"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{E281853C-F457-3527-B294-35A4E6EF76E2}\InprocServer32
- ThreadingModel = "Apartment"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{E43E4DE6-3F2A-DABA-82DF-3A3B59484001}\InprocServer32
- ThreadingModel = "Apartment"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{4C7E5898-C71D-8B0B-A0F8-00D06AFEBEE6}\InprocServer32
- ThreadingModel = "Apartment"
Step 5
Search and delete these files
- %Windows%\qnqsp1.dll
- %Program Files%\Common Files\Adobe\Acrobat\ActiveX\AcroIEHelperShim.dll.$
Note: To do a search for the following files, right-click Start then click Search... or Find..., depending on the version of Windows you are running. For each file to be deleted, type its file name in the Named input box. In the Look In drop-down list, select My Computer, then press Enter.
Step 6
Scan your computer with your Trend Micro product to delete files detected as TROJ_AGENT_0000176.TOMA. 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 7
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.
- %Temp%\1.tmp
- %Temp%\2.tmp
- %Program Files%\Common Files\Adobe\Acrobat\ActiveX\AcroIEHelperShim.dll
Step 8
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_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{18DF081C-E8AD-4283-A596-FA578C2EBDC3}
- InprocServer32
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{18DF081C-E8AD-4283-A596-FA578C2EBDC3}
- ProgID
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{18DF081C-E8AD-4283-A596-FA578C2EBDC3}
- Programmable
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{18DF081C-E8AD-4283-A596-FA578C2EBDC3}
- TypeLib
- In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{18DF081C-E8AD-4283-A596-FA578C2EBDC3}
- VersionIndependentProgID
- In HKEY_CLASSES_ROOT\CLSID
- {18DF081C-E8AD-4283-A596-FA578C2EBDC3}
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Browser Helper Objects
- {18DF081C-E8AD-4283-A596-FA578C2EBDC3}
- In HKEY_CURRENT_USER\SOFTWARE\Microsoft\Internet Explorer
- URLSearchHooks
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Discardable\PostSetup\Component Categories\{00021493-0000-0000-C000-000000000046}
- Enum
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Discardable\PostSetup\Component Categories\{00021494-0000-0000-C000-000000000046}
- Enum
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