TROJ_QHOST.AFG
Trojan:Win32/Qhost.HB (Microsoft); Qhost-Gen!bm (McAfee); Infostealer (Symantec); Trojan-PSW.Win32.MoonBlk.bj (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt); Gen:Trojan.Heur.hqWaXjka4Nm (FSecure); May be infected by unknown virus Win32/DH{Bg} (AVG)
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.
It modifies files, disabling programs and applications from properly running.
It deletes itself after execution.
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 modifies the following files:
- %System%\drivers\etc\hosts
(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)
It deletes the following files:
- %System%\dia3.ini
(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)
It modifies the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Windows
AppInit_DLLs = "ws2help.dll"
Dropping Routine
This Trojan drops the following files:
- %User Temp%\pinghux.exe
- %Windows%\IRIMGV3.bmp
- %System%\ws2helpXP.dll
(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, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.. %Windows% is the Windows folder, which is usually C:\Windows.. %System% is the Windows system folder, which is usually C:\Windows\System32.)
Other Details
This Trojan deletes itself after execution.
This report is generated via an automated analysis system.
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
Restore these modified registry values
Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Windows
- AppInit_DLLs = "ws2help.dll"
Step 3
Search and delete these components
- %User Temp%\pinghux.exe
- %Windows%\IRIMGV3.bmp
- %System%\ws2helpXP.dll
Step 4
Scan your computer with your Trend Micro product to delete files detected as TROJ_QHOST.AFG. 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 5
Restore deleted/modified files and/or registry entries from backup
*Note: Only Microsoft-related files/keys/values will be restored. If this malware/grayware also deleted registry keys/values related to programs that are not from Microsoft, please reinstall those programs on your computer.
- %System%\drivers\etc\hosts
Step 6
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%\dia3.ini
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