安装包逆向1

1.找到程序的入口点

在IDA中我们看到函数非常多，但是一般都是有主要的入口的，所以找一下有没有主函数
可以直接
Ctr+F直接查找
在这里插入图片描述

在这里插入图片描述

CNsInstaller::CNsInstaller

这里搞半天在获取文件路径
在这里插入图片描述

CNsInstaller::StartInstall

在这里插入图片描述

CNsInstaller::InstallFunc

char __thiscall CNsInstaller::InstallFunc(CNsInstaller *this)
{const wchar_t *v2; // eaxCNsInstaller *v3; // ecxconst WCHAR *v4; // eax__int64 v5; // raxconst wchar_t *v6; // eaxCNsInstaller *v7; // edxconst WCHAR *v8; // eaxstruct CNsApp *v9; // eaxCNsApp *v10; // eaxconst WCHAR *v11; // eaxchar *v12; // [esp-24h] [ebp-A58h]char *v13; // [esp-20h] [ebp-A54h]int Offset; // [esp+28h] [ebp-A0Ch] BYREFint v15; // [esp+2Ch] [ebp-A08h] BYREFint v16; // [esp+30h] [ebp-A04h] BYREFint Buff; // [esp+34h] [ebp-A00h]int v18; // [esp+38h] [ebp-9FCh] BYREFchar v19[4]; // [esp+3Ch] [ebp-9F8h] BYREFchar v20[5]; // [esp+40h] [ebp-9F4h] BYREFchar v21; // [esp+45h] [ebp-9EFh]char v22; // [esp+46h] [ebp-9EEh]char v23; // [esp+47h] [ebp-9EDh]FILE *Stream; // [esp+48h] [ebp-9ECh]CNsInstaller *v25; // [esp+4Ch] [ebp-9E8h]LONG dwNewLong[297]; // [esp+50h] [ebp-9E4h] BYREFWCHAR Buffer[202]; // [esp+4F4h] [ebp-540h] BYREFWCHAR String1[202]; // [esp+688h] [ebp-3ACh] BYREFWCHAR Filename[260]; // [esp+81Ch] [ebp-218h] BYREFint v30; // [esp+A30h] [ebp-4h]v25 = this;memset(Filename, 0, sizeof(Filename));GetModuleFileNameW(0, Filename, 0x104u); 用于获取当前进程已加载模块的文件路径*((_QWORD *)v25 + 2) = FileSize(Filename);Buff = NsResGetBuff(0x1F41u, L"BIN", &Offset);这里也很重要，从获取buff点进去看尝试从资源中检索包含安装数据的缓冲区，该资源由 "BIN" 和 ID 0x1F41 标识if ( !Buff ){memset((char *)v25 + 36, 0, 0x15C8u);return 0;}Stream = _wfopen(Filename, L"rb");if ( !Stream )return 0;fseek(Stream, Offset, 0);memset((char *)v25 + 36, 0, 0x15C8u);fread((char *)v25 + 36, 0x15C8u, 1u, Stream);将文件的前 4096 字节 (0x15C8) 读入 CNsInstaller 对象中的缓冲区CNsInstaller::InitPath(v25, (CNsInstaller *)((char *)v25 + 36));DoReport(L"http://hofosoft.cn/api/report.asp", L"install", (LPCWSTR)v25 + 18);这里看到火凤一个网站CNsInstaller::CheckValid(v25);CNsInstaller::InstallComponent(v25);v2 = (const wchar_t *)Json::StaticString::c_str((CNsInstaller *)((char *)v25 + 5808));使用 Json::StaticString::c_str 从安装数据缓冲区中提取文件路径。CNsInstaller::CheckDir(v25, v2, &word_11FBED4);使用 CNsInstaller::CheckDir 检查目录是否存在v15 = 0;Buff = NsResGetBuff(0x1F5Bu, L"BIN", &v15);检索包含安装数据的另一个缓冲区 (ID 0x1F5B)。if ( Buff && v15 ){v3 = v25;*((_DWORD *)v25 + 4) = 0;*((_DWORD *)v3 + 5) = 0;memset(String1, 0, sizeof(String1));fread(String1, 0x194u, 1u, Stream);CNsInstaller::ExtractFile(v25, String1, Stream);使用 CNsInstaller::ExtractFile 从可执行文件中提取文件memset(String1, 0, sizeof(String1));fread(String1, 0x194u, 1u, Stream);if ( lstrcmpW(String1, L"SPLIT") || *(_DWORD *)&String1[200] )检查文件名是否为 "SPLIT" 以及偏移量 200 处是否存在特定值return 0;fclose(Stream);sub_11396A0(Filename);v30 = 0;sub_113D410(v20);sub_113D470((wchar_t *)L".exe", L".hf");v4 = (const WCHAR *)Json::StaticString::c_str((Json::StaticString *)v20);获取新文件的大小并将其存储在 CNsInstaller 对象中v5 = FileSize(v4);*((_QWORD *)v25 + 2) = v5;*((_QWORD *)v25 + 3) = 0i64;计算可执行文件的剩余大小以进行进一步处理v6 = (const wchar_t *)Json::StaticString::c_str((Json::StaticString *)v20);Stream = _wfopen(v6, L"rb");//这里对文件进行读写的操作if ( !Stream ){v23 = 0;v30 = -1;sub_1139680(v20);return v23;}v30 = -1;sub_1139680(v20);}else{*((_QWORD *)v25 + 2) -= Offset;v7 = v25;*((_DWORD *)v25 + 6) = 5576;*((_DWORD *)v7 + 7) = 0;}if ( *((__int64 *)v25 + 2) >= 419430400 ){if ( *((__int64 *)v25 + 2) >= 0x100000000i64 )*((_DWORD *)v25 + 8) = 2;else*((_DWORD *)v25 + 8) = 1;}else{*((_DWORD *)v25 + 8) = 0;}while ( !feof(Stream) ){if ( *((_BYTE *)v25 + 8) )return 0;memset(Buffer, 0, sizeof(Buffer));fread(Buffer, 0x194u, 1u, Stream);if ( !lstrcmpW(Buffer, &off_11FBF4C) && !*(_DWORD *)&Buffer[200] )检查缓冲区内容是否指示安装数据部分的结尾break;if ( *(_DWORD *)&Buffer[200] == -1 ){CNsInstaller::CheckDir(v25, Buffer, 0);}else{*((_QWORD *)v25 + 3) += 404i64;if ( !CNsInstaller::ExtractFile(v25, Buffer, Stream) )break;}}fclose(Stream);sub_11397C0(&v18);v30 = 1;sub_1139D70((int)&v18, (wchar_t *)L"%s\\%s", *((_DWORD *)v25 + 1452));v8 = (const WCHAR *)Json::StaticString::c_str((Json::StaticString *)&v18);if ( PathFileExistsW(v8) ){if ( *((_BYTE *)v25 + 5816) ){sub_11397C0(&v16);LOBYTE(v30) = 4;sub_1139D70((int)&v16, (wchar_t *)L"%s\\%s", *((_DWORD *)v25 + 1452));v11 = (const WCHAR *)Json::StaticString::c_str((Json::StaticString *)&v16);DeleteFileW(v11);LOBYTE(v30) = 1;sub_1139680(&v16);}else{CNsInstaller::WriteReg(v25, (CNsInstaller *)((char *)v25 + 36));CNsInstaller::CreateShortcuts(v25, (CNsInstaller *)((char *)v25 + 36));CNsInstaller::CreateUninstallCfg(v25, (CNsInstaller *)((char *)v25 + 36));}CNsInstaller::ExecScript(v25, (const wchar_t *)v25 + 1868);CNsInstaller::ImportReg(v25);SendMessageW(*(HWND *)v25, 0x7E9u, 0x2710u, 0);v21 = 1;v30 = -1;sub_1139680(&v18);return v21;}else{sub_11397C0(v19);LOBYTE(v30) = 2;if ( isEnglish() )sub_11395C0(v19, L"Installation failed, does not have write permission!");elsesub_11395C0(v19, &unk_11FBFD8);sub_113DBE0();LOBYTE(v30) = 3;v13 = (char *)CNsApp::Instance() + 530;v12 = (char *)Json::StaticString::c_str((Json::StaticString *)v19);v9 = CNsApp::Instance();sub_113E350((LONG)dwNewLong, *((_DWORD *)v9 + 1), v12, v13, 0, 6, 300, 160, 8, 9, 1);v10 = CNsApp::Instance();CNsApp::ExitApp(v10);v22 = 0;LOBYTE(v30) = 2;sub_113DE10(dwNewLong);LOBYTE(v30) = 1;sub_1139680(v19);v30 = -1;sub_1139680(&v18);return v22;}
}