Patching bytes without knowing the address

[Icaros]

Hello, I'm having a little problem with patching an array of bytes in a running process.

What am I trying to achieve :

A game launcher has a web browser that loads the official website of the game, I want to patch the URL to load my, or any random website instead.

What have I achieved so far :

I am able to attach OllyDbg to the game launcher and patch the bytes maually, then when I continue te execution of the launcher the brower successfully loads my website.

the problem :

I cannot seem to be able to make this work in VB. I have managed to obtain the following piece of code with which I am experimenting.

 Public Function FindPattern(ByVal ProcessName As String, ByVal Pattern As Byte(), ByVal SearchRange As Integer) As Integer

        Dim P As Process() = Process.GetProcessesByName(ProcessName)
        If P.Length = 0 Then
            Return -1
        End If

        Dim _Buffer As Byte() = New Byte(SearchRange) {}
        ReadProcessMemory(P(0).Handle, P(0).MainModule.BaseAddress, _Buffer, _Buffer.Length, 0)

        Dim sBytes As Integer() = New Integer(255) {}
        Dim Len As Integer = Pattern.Length - 1, Dex = 0

        For i As Integer = 255 To 0 Step -1
            sBytes(i) = Pattern.Length
        Next

        For i As Integer = Len To 0 Step -1
            sBytes(Pattern(i)) = Len
        Next

        While Dex <= _Buffer.Length - Pattern.Length
            Dim i As Integer = Len
            While _Buffer(Dex + i) = Pattern(i)
                If i = 0 Then
                    Return P(0).MainModule.BaseAddress.ToInt32 + Dex
                End If
                i -= 1
            End While
            Dex += sBytes(_Buffer(Dex + Len))
        End While

        Return -1
    End Function

Usage :

MsgBox(FindPattern("ClientLoader", url, &H3DF000).ToString)

Unfortunately I feel as though I do not fully comprehend what is does. More specifically then what the SearchRange should be, as I have tried the size of the module from olly, hoping it would scan throuh the whole process memory. Unfortunaly it always returns -1, meaning it has not found anything ..
I would appreciate if you could help me understand what am I doing wrong, possibly edit the code or show other examples.
I believe that if I am able to search for and find a pattern of bytes in the memory, patching it will be a straight forward process. I am able to patch an .exe, read/write from and into addresses etc. Unfortunately the address of the URL in the memory of this game launcher is always different and for the life of me I cannot find a pointer or a static address. Which is why I am hoping to find the address using pattern scanning. Or just patch the pattern if found.

Thank you

[Icaros]

Anyone? I coud really use some help.

[RoPMadM]

Try to dump a memory region and try to find the pattern there.

 

Public Function patternscan(ByVal startindex As Long, ByVal pattern As Byte(), ByVal mask As String, ByVal bytearraytoscan() As Byte) As IntPtr

        Dim maskk(0 To mask.Length - 1) As String
        For i As Integer = 0 To mask.Length - 1
            maskk(i) = mask.Substring(i, 1)
        Next
        For i As Integer = 0 To bytearraytoscan.Length - pattern.Length
            Dim n(pattern.Length - 1) As Byte
            Array.Copy(bytearraytoscan, i, n, 0, pattern.Length)
            For k As Integer = 0 To n.Length - 1
                If maskk(k).ToLower = "x" Then
                    If pattern(k) = n(k) Then
                        If k = n.Length - 1 Then
                            Return startindex + i
                        Else
                            Continue For
                        End If
                    Else
                        Exit For
                    End If
                    Continue For
                End If
            Next
        Next
        Return 0
    End Function

 Dim bytearraytoscan() as Byte = ReadMemory(Of Byte())(BaseAdress, dumpSize), False)
 Dim pattern As Byte() = {&H0, &H0, &H0, &H60, &H9D, &H0}
 Dim mask As String = "x??xx?"
    
 Dim address As Integer = patternscan(0, pattern, mask, bytearraytoscan())

If this isn't working, try to find basicly a static pointer. I'm sure there is one.