TROJ_QHOST.AGB
W32.HLLP.Yero.Worm.dr(Norton), a variant of Win32/Qhost.ORW trojan(Eset)
Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)
![](/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.
Other System Modifications
This Trojan adds the following registry keys:
HKEY_CLASSES_ROOT\CLSID\{241AEB64-8376-4889-882D-349B03DEC7B8}
HKEY_CLASSES_ROOT\CLSID\{241AEB64-8376-4889-882D-349B03DEC7B8}\
InprocServer32
HKEY_LOCAL_MACHINE\SOFTWARE\NetZoneSoft
HKEY_LOCAL_MACHINE\SOFTWARE\NetZoneSoft\
NxDXP
HKEY_LOCAL_MACHINE\SOFTWARE\NetZoneSoft\
NxDXP\Option
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{241AEB64-8376-4889-882D-349B03DEC7B8}
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{241AEB64-8376-4889-882D-349B03DEC7B8}\InprocServer32
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Browser Helper Objects\{241AEB64-8376-4889-882D-349B03DEC7B8}
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\nxd
It adds the following registry entries:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\nxd
TCP_PORT = 0
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\nxd
UDP_PORT = 0
HKEY_CLASSES_ROOT\CLSID\{241AEB64-8376-4889-882D-349B03DEC7B8}\
InprocServer32
Default = "%System%\exmon.dll"
HKEY_CLASSES_ROOT\CLSID\{241AEB64-8376-4889-882D-349B03DEC7B8}\
InprocServer32
ThreadingModel = "Apartment"
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{241AEB64-8376-4889-882D-349B03DEC7B8}\InprocServer32
Default = "%System%\exmon.dll"
HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{241AEB64-8376-4889-882D-349B03DEC7B8}\InprocServer32
ThreadingModel = "Apartment"
HOSTS File Modification
This Trojan adds the following strings to the Windows HOSTS file:
- 127.0.0.1 auto.search.msn.com
- 127.0.0.1 domainhelp.search.com
- 127.0.0.1 sea.search.msn.com
Other Details
This Trojan connects to the following possibly malicious URL:
- http://www.{BLOCKED}8.com
- http://{BLOCKED}d.net
SOLUTION
Step 1
Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.
Step 2
Restart in Safe Mode
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.
- HKEY_CLASSES_ROOT\CLSID\{241AEB64-8376-4889-882D-349B03DEC7B8}
- HKEY_LOCAL_MACHINE\SOFTWARE\NetZoneSoft
- HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{241AEB64-8376-4889-882D-349B03DEC7B8}
- HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Browser Helper Objects\{241AEB64-8376-4889-882D-349B03DEC7B8}
- HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\nxd
Step 4
Remove these strings added by the malware/grayware/spyware in the HOSTS file
- 127.0.0.1 auto.search.msn.com
- 127.0.0.1 domainhelp.search.com
- 127.0.0.1 sea.search.msn.com
Step 5
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_QHOST.AGB. 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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