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  • Online Scan: Analyze dnlauncher.exe file and fix runtime errors, Fix System Error
    Welcome to my blog. I found a malicious code that was added into the dnlauncher.exe file. Due to infection by malicious code, the file contents changed. The MD5 value of the infected file is: 52874bb7acecb5826cad09a60de0994e, and the file size is: 1.2 MB ( 1,244,240 bytes )
    Risk level of malicious code
     
     
     
     
     
    ( 3 stars by 147 users )
    Behavior of malicious code ( 250 votes ) If you know more this malicious code, please vote. We sincerely hope you may share your information with other computer users and help them.
    1. Infect file
    9.2% (23)
    2. Intentionally destroy data
    9.6% (24)
    3. Steal personal privacy
    11.2% (28)
    4. Infect other computers through the Internet
    15.2% (38)
    5. Install the backdoor program so that the computer is controlled remotely
    12% (30)
    6. Cheat or threaten users to buy something
    12.8% (32)
    7. Download and install other programs without permission in the background
    15.2% (38)
    8. Pop up various advertisements and induce users to click
    14.8% (37)
    Binary Code Analysis:
    When the program runs, the PE loader will try to load the file to 0x00400000 in the virtual address space, Address Of Entry Point: 0x0006E9E0. This file has 4 SECTION.
    DOS Header
    DOS Stub
    ...
     
    NT File Signature
    NT HEADER
    FILE HEADER
     
    OPTIONAL HEADER
    Data Directory
    .text SECTION #1
    .rdata SECTION #2
    .data SECTION #3
    .rsrc SECTION #4
    About this malicious code
    This malicious code is a 32-bit program that infects an EXE file. When the file is run or the file is loaded, the malicious code in the file is run first. Later, this malicious code also infects the following files:

    • dnlauncher.exe
    • dnlauncher.ocx

    Tip: There is something I must emphasize. The file names listed above are infected by malicious code. It does not mean that all files named by these names are malicious files. It is inaccurate to determine whether a file is a malicious program based on its file name.

    The malicious code also infects files on the following path:

    • c:\documents and settings\admin\my documents\dragon nest\
    • c:\cherrydegames\dragon nest\
    • c:\program files (x86)\eyedentity games\dragonnest\
    Tip: The code of most malicious files is fixed, rarely changed, which means, this type of malicious files regardless of which computer they are in, will copy themselves into the pre-set path, so we can go to the path listed above to find this file, and there is a great chance to find it.
    Are all the files with the same file name listed above and with the same path malicious files?
    Of course not. The file name is just the identification of the file. Strictly speaking, the file is modified by malicious code.

    The following are methods commonly used by malicious code in order to confuse users:

    • Deliberately modify their own file name to some system file name, or some well-known software name.
    • Generate malicious files in the system folder or in the installation folder of some well-known software, and even name their own folder with an antivirus software name (actually the user did not install this antivirus software). In fact, these malicious files are not system files, nor part of the famous software.

    For example, one of the most common system file names is: explorer.exe, and under normal circumstances, the system only has an explorer.exe process. When you open the Task Manager and find that there are two or more explorer.exe processes, it is likely the camouflage of some malicious viruses. As shown in the following figure, there are two explorer.exe processes in Task Manager.

    When I find the path where the file is located, it will be clear that the real explorer.exe system file is located under "C:\ Windows\", and the malicious file that pretends to be system process is under the other path.

    The running status of the dnlauncher.exe file that is infected with malicious code:
    dnlauncher.exe running statusTake up memory 63K
    Occupy CPU resources between 59% - 76%
    Run the program with the SYSTEM permissions.
    At runtime, 16 Windows system files, 1 external files (not owned by the Windows system), are called
    Windows system files
  • File name
  • Number of calling functions
  • KERNEL32.dll
  • 161
  • USER32.dll
  • 161
  • GDI32.dll
  • 56
  • comdlg32.dll
  • 1
  • WINSPOOL.DRV
  • 3
  • ADVAPI32.dll
  • 9
  • SHELL32.dll
  • 4
  • COMCTL32.dll
  • 2
  • SHLWAPI.dll
  • 5
  • oledlg.dll
  • 1
  • ole32.dll
  • 18
  • OLEAUT32.dll
  • 19
  • WINMM.dll
  • 1
  • WININET.dll
  • 7
  • VERSION.dll
  • 3
  • d3d9.dll
  • 1
  • Not owned by the windows system
  • File name
  • Number of calling functions
  • GPKitClt.dll
  • 1
  • In general, the most accurate way to determine if a file is a malicious file is to analyze its code and see what happens when these functions are called while the program is running. Does it have malicious behavior (destroying data or stealing data)? I have listed the functions called by this file and some internal data, but there is too much data, I can't show them all here. →Click here← to see the full binary code analysis page.
    dnlauncher.exe runtime behavior analysis
    The KERNEL32.dll dynamic link library is loaded and the functions in the file are called: ( Kernel32.dll is a very important 32-bit dynamic link library file in the Windows operating system. It is a kernel-level file. It controls the system's memory management, data input and output operations and interrupt handling. When the Windows operating system starts, kernel32.dll resides in a specific write-protected area of memory, so that other programs cannot occupy this memory area. )
  • SetErrorMode: Controls whether the system will handle the specified types of serious errors or whether the process will handle them.
  • GetStartupInfoW: Retrieves the contents of the STARTUPINFO structure that was specified when the calling process was created.
  • UnhandledExceptionFilter: An application-defined function that passes unhandled exceptions to the debugger, if the process is being debugged.
  • SetUnhandledExceptionFilter: Enables an application to supersede the top-level exception handler of each thread of a process.
  • IsDebuggerPresent: Determines whether the calling process is being debugged by a user-mode debugger.
  • GetSystemTimeAsFileTime: Retrieves the current system date and time. The information is in Coordinated Universal Time (UTC) format.
  • RtlUnwind: Initiates an unwind of procedure call frames.
  • ExitProcess: Ends the calling process and all its threads.
  • WriteConsoleW: Writes a character string to a console screen buffer beginning at the current cursor location.
  • GetStdHandle: Retrieves a handle to the specified standard device (standard input, standard output, or standard error).
  • GetSystemInfo: Retrieves information about the current system.
  • FreeEnvironmentStringsA: Frees a block of environment strings.
  • FreeEnvironmentStringsW: Frees a block of environment strings.
  • GetEnvironmentStringsW: Retrieves the environment variables for the current process.
  • GetStartupInfoA: Retrieves the contents of the STARTUPINFO structure that was specified when the calling process was created.
  • QueryPerformanceCounter: Retrieves the current value of the performance counter, which is a high resolution (<1us) time stamp that can be used for time-interval measurements.
  • GetConsoleMode: Retrieves the current input mode of a console's input buffer or the current output mode of a console screen buffer.
  • WriteConsoleA: Writes a character string to a console screen buffer beginning at the current cursor location.
  • SetEnvironmentVariableA: Sets the contents of the specified environment variable for the current process.
  • TlsAlloc: Allocates a thread local storage (TLS) index. Any thread of the process can subsequently use this index to store and retrieve values that are local to the thread, because each thread receives its own slot for the index.
  • TlsGetValue: Retrieves the value in the calling thread's thread local storage (TLS) slot for the specified TLS index. Each thread of a process has its own slot for each TLS index.
  • GetCurrentProcess: Retrieves a pseudo handle for the current process.
  • DuplicateHandle: Duplicates an object handle.
  • FlushFileBuffers: Flushes the buffers of a specified file and causes all buffered data to be written to a file.
  • InterlockedExchange: Sets a 32-bit variable to the specified value as an atomic operation.
  • GetModuleHandleA: Retrieves a module handle for the specified module. The module must have been loaded by the calling process.
  • GetCurrentThreadId: Retrieves the thread identifier of the calling thread.
  • LoadLibraryA: Loads the specified module into the address space of the calling process. The specified module may cause other modules to be loaded.
  • TlsSetValue: Stores a value in the calling thread's thread local storage (TLS) slot for the specified TLS index. Each thread of a process has its own slot for each TLS index.
  • GetProcAddress: Retrieves the address of an exported function or variable from the specified dynamic-link library (DLL).
  • LoadLibraryW: Loads the specified module into the address space of the calling process. The specified module may cause other modules to be loaded.
  • GetModuleHandleW: Retrieves a module handle for the specified module. The module must have been loaded by the calling process.
  • TerminateProcess: Ends the calling process and all its threads.
  • OpenProcess: Opens an existing local process object.
  • Process32NextW: Retrieves information about the next process recorded in a system snapshot.
  • Process32FirstW: Retrieves information about the first process encountered in a system snapshot.
  • GetCurrentProcessId: Retrieves the process identifier of the calling process.
  • CreateToolhelp32Snapshot: Takes a snapshot of the specified processes, as well as the heaps, modules, and threads used by these processes.
  • SetCurrentDirectoryA: Changes the current directory for the current process.
  • WaitForSingleObject: Waits until the specified object is in the signaled state or the time-out interval elapses.
  • TerminateThread: Terminates a thread.
  • GetTickCount: Retrieves the number of milliseconds that have elapsed since the system was started, up to 49.7 days.
  • CreateThread: Creates a thread to execute within the virtual address space of the calling process.
  • GetLastError: Retrieves the calling thread's last-error code value.
  • GetModuleFileNameA: Retrieves the fully qualified path for the file that contains the specified module.
  • GetModuleFileNameW: Retrieves the fully qualified path for the file that contains the specified module.
  • The USER32.dll dynamic link library is loaded and the functions in the file are called: ( User32.dlll is a Windows user interface related application program interface for Windows processing, basic user interface and other features, such as creating windows and sending messages. )
  • GetWindowRect: Retrieves the dimensions of the bounding rectangle of the specified window.
  • The ADVAPI32.dll dynamic link library is loaded and the functions in the file are called: ( Advapi32.dll is part of a high-level API application interface service library that contains functions related to object security, registry manipulation, and event logging. It is generally located in the system directory: \WINDOWS\system32\ )
  • RegOpenKeyExW: Opens the specified registry key. Note that key names are not case sensitive.
  • RegQueryValueW: Retrieves the data associated with the default or unnamed value of a specified registry key.
  • RegQueryValueExW: Retrieves the data associated with the default or unnamed value of a specified registry key.
  • RegOpenKeyW: Opens the specified registry key. Note that key names are not case sensitive.
  • The SHELL32.dll dynamic link library is loaded and the functions in the file are called: ( Shell32.dll is an important file stored in the \Windows\System32\ folder. Normally it is created automatically during the installation of the operating system and is critical to the normal operation of the system. Under normal circumstances, users are not advised to make arbitrary modifications to this type of file. Its existence plays an important role in maintaining the stability of the computer system. )
  • ShellExecuteW: Performs an operation on a specified file.
  • The following files have been identified as malicious files. Some files are variants of dnlauncher.exe; some files are another type of malicious file, but use the same file name as dnlauncher.exe.

    It is a simple and effective way to determine whether a file is a malicious file by a hash value, which has lower false detection rate than the "static signature" method. So, if the MD5 value of a file on the computer is the same as the MD5 value listed below, then it is sure that the file is a malicious file.

    This is my analysis results to the code of each malicious below, mainly provided to industry professionals who engage in the maintenance of computer security. If you are interested, you can also have a view, but it may require certain computer knowledge.
    • File Md5
    • File Size
    • File Bit
    • File Type
    • Binary Code Analysis

    How to repair or remove dnlauncher.exe

    Method 1: Manual Removal

    • Reboot the system and then enter safe mode (Click here to see how each Windows version (XP/Vista/7/8/10) goes into safe mode)

    • Open Task Manager and if dnlauncher.exe is running, end this program.
    dnlauncher.exe running status

    • Show all hidden files.
    Step: "My Computer" -> "Floder Options" ->"View" -> "Show hidden files, folders, and drives"

    • Malicious code used to generate or infect files on the following paths, so you need to one by one go into the following path, and delete all files [  dnlauncher.exe, dnlauncher.ocx  ]

    • c:\documents and settings\admin\my documents\dragon nest\
    • c:\cherrydegames\dragon nest\
    • c:\program files (x86)\eyedentity games\dragonnest\

    • Finally, restart your computer.

    Method 2: Automatic Removal Using Tools (Recommended)

    1. Download Removal Tool

    2. Save it into your computer and install it step by step.

    3. During the installation process, the user interface is available in multiple languages and is easy to use.

    4. The installation process is an online installation, so after the installation is complete, the software version and virus database are up-to-date.

    5. After the installation is complete, run the antivirus software and click the "Scan Computer Now!" button to scan the whole system.

    6. Tick "Select all" and then Remove to delete all threats. Reboot your computer.

    When you find your operating system is abnormal, and the file name listed above appears in the Task Manager, or there are several processes in running with the same name as the core file name, it is best to download the anti-virus software to check your system.

    Online detection of dnlauncher.exe

    If you don't know if dnlauncher.exe is infected with malicious code on your computer, you may also use online scan tool.

    • Use the following online detection function to check the file.
  • • Enter the file name, or file MD5, for the query.
  • • You can also scan a file online. Click the "Upload File" button, and then click the "submit" button, to immediately detect whether the file is a virus. (Tip: The maximum size of the file uploaded cannot exceed 8MB)
  • How do I use the T21 engine for online scanning?

    T21 can detect unknown files online, mainly using "behavior-based" judgment mechanism. It is very simple to use T21.

    1. Click the "Upload File" button, select the file you want to detect, and then click "Submit".
    2. The next step is to wait for the system to check, which may take a little time, so please be patient.
    3. When the T21 scan engine finishes detection, the test results are immediately fed back, as shown below:

    • If you suspect that there are malicious files on your computer, but you cannot find where they are, or if you want to make a thorough check on your computer, you can download the automatic scanning tool.

    If you want to know what kind of T21 system is, you can click here to view the introduction of T21. You can also go to the home page to read the original intention and philosophy of my development of T21 system.

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    Copyright statement: The above data is obtained by my analysis, and without authorization, you may not copy or reprint it.
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