TROJ_DROPPER.HXN
PWS:Win32/OnLineGames.EW (Microsoft); PWS-Mmorpg!bfn (McAfee); Trojan Horse (Symantec); Trojan-Dropper.Win32.Agent.aisf (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt); Trojan horse PSW.OnlineGames_r.BX, Trojan horse PSW.OnlineGames_r.BX.dropper (AVG)
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
89,600 bytes
EXE
Yes
07 Jul 2013
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 as a system service to ensure its automatic execution at every system startup by adding the following registry keys:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\defaultlib\Parameters
Other System Modifications
This Trojan adds the following registry keys:
HKEY_LOCAL_MACHINE\SOFTWARE\INSTALLCOOL\
defaultlib
It adds the following registry entries:
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\defaultlib
Description = "Service to schedule Avira AntiVir!. "
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\defaultlib\Parameters
ServiceDll = "%System%\u18617751.dll"
HKEY_LOCAL_MACHINE\SOFTWARE\INSTALLCOOL\
defaultlib
InstallModule = "{malware path and file name}"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\defaultlib
Type = "12"
It modifies the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\SvcHost
netsvcs = "{random characters}"
(Note: The default value data of the said registry entry is {random values}.)
Dropping Routine
This Trojan drops the following files:
- %System%\u18617751.dll
(Note: %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
9.300
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.
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\defaultlib
- Parameters
- In HKEY_LOCAL_MACHINE\SOFTWARE\INSTALLCOOL
- defaultlib
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\SYSTEM\ControlSet001\Services\defaultlib
- Description = "Service to schedule Avira AntiVir!. "
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\defaultlib\Parameters
- ServiceDll = "%System%\u18617751.dll"
- In HKEY_LOCAL_MACHINE\SOFTWARE\INSTALLCOOL\defaultlib
- InstallModule = "{malware path and file name}"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\defaultlib
- Type = "12"
Step 5
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\SvcHost
- From: netsvcs = "{random characters}"
To: netsvcs = ""{random values}""
- From: netsvcs = "{random characters}"
Step 6
Search and delete this file
- %System%\u18617751.dll
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_DROPPER.HXN. 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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