TROJ_DLOADR.ZTP
Adware:Win32/Grobim (Microsoft); [2.nsis]:Downloader.a!bbz, [3.nsis]:Generic.dx!bcmc (McAfee); Trojan.ADH (Symantec); ARC:NSIS, [$PLUGINSDIR\chrsvr.dll]:Trojan.Win32.Zapchast.tvq (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt); Dropped:Trojan.Generic.7050246 (FSecure)
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
217,304 bytes
EXE
Yes
26 May 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.
Installation
This Trojan creates the following folders:
- %Program Files%\pilotvob
- %System Root%\DOCUME~1
- %System Root%\DOCUME~1\ADMINI~1
- %User Profile%\LOCALS~1
- %User Temp%\nsj3.tmp
(Note: %Program Files% is the default Program Files folder, usually C:\Program Files.. %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.. %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.)
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\pilotvob\Parameters
Other System Modifications
This Trojan deletes the following files:
- %User Temp%\nsj1.tmp
- %User Temp%\nsj3.tmp
- %System Root%\DelUS.bat
(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.. %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)
It adds the following registry entries:
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\pilotvob\Parameters
ServiceDll = "%Program Files%\pilotvob\pilotvob.dll"
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:
- %User Temp%\nsj2.tmp
- %Program Files%\pilotvob\pilotvob.dll
- %User Temp%\nsj3.tmp\chrsvr.dll
- %User Temp%\nsj3.tmp\System.dll
- %User Temp%\nsj3.tmp\Math.dll
- %User Temp%\nsj3.tmp\DLLWebCount.dll
- %User Temp%\nsj3.tmp\SelfDelete.dll
- \DelUS.bat
(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.. %Program Files% is the default Program Files folder, usually C:\Program Files.)
Other Details
This Trojan connects to the following possibly malicious URL:
- http://e{BLOCKED}ounter.{BLOCKED}o.kr/check_{BLOCKED}ounter.php?{random characters}
It deletes itself after execution.
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
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\pilotvob
- Parameters
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\pilotvob\Parameters
- ServiceDll = "%Program Files%\pilotvob\pilotvob.dll"
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\Windows NT\CurrentVersion\SvcHost
- From: netsvcs = "{random characters}"
To: netsvcs = ""{random values}""
- From: netsvcs = "{random characters}"
Step 6
Search and delete these files
- %User Temp%\nsj2.tmp
- %Program Files%\pilotvob\pilotvob.dll
- %User Temp%\nsj3.tmp\chrsvr.dll
- %User Temp%\nsj3.tmp\System.dll
- %User Temp%\nsj3.tmp\Math.dll
- %User Temp%\nsj3.tmp\DLLWebCount.dll
- %User Temp%\nsj3.tmp\SelfDelete.dll
- \DelUS.bat
Step 7
Search and delete these folders
- %Program Files%\pilotvob
- %System Root%\DOCUME~1
- %System Root%\DOCUME~1\ADMINI~1
- %User Profile%\LOCALS~1
- %User Temp%\nsj3.tmp
Step 8
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_DLOADR.ZTP. 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 9
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.
- %User Temp%\nsj1.tmp
- %User Temp%\nsj3.tmp
- %System Root%\DelUS.bat
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