From e8b0aece0cbaef9d942a9f935c3356e9c1b0d70c Mon Sep 17 00:00:00 2001
From: gggaa2152 <60614405+gggaa2152@users.noreply.github.com>
Date: Sat, 4 Apr 2026 21:36:43 +0800
Subject: [PATCH] Create injector.cpp

---
 injector.cpp | 152 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 152 insertions(+)
 create mode 100644 injector.cpp

diff --git a/injector.cpp b/injector.cpp
new file mode 100644
index 000000000..45669e88a
--- /dev/null
+++ b/injector.cpp
@@ -0,0 +1,152 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/ptrace.h>
+#include <sys/wait.h>
+#include <sys/user.h>
+#include <dirent.h>
+#include <dlfcn.h>
+#include <sys/uio.h>
+#include <elf.h>
+#include <android/log.h>
+
+#define LOG_TAG "JKInjector"
+#define LOGI(...) __android_log_print(ANDROID_LOG_INFO, LOG_TAG, __VA_ARGS__)
+#define LOGE(...) __android_log_print(ANDROID_LOG_ERROR, LOG_TAG, __VA_ARGS__)
+
+/**
+ * Find process ID by package name
+ */
+pid_t find_pid(const char* process_name) {
+    DIR* dir = opendir("/proc");
+    if (!dir) return -1;
+    struct dirent* entry;
+    while ((entry = readdir(dir))) {
+        size_t pid = atoi(entry->d_name);
+        if (pid <= 0) continue;
+        char path[256], cmdline[256];
+        snprintf(path, sizeof(path), "/proc/%zu/cmdline", pid);
+        FILE* f = fopen(path, "r");
+        if (f) {
+            if (fgets(cmdline, sizeof(cmdline), f)) {
+                if (strcmp(cmdline, process_name) == 0) {
+                    fclose(f);
+                    closedir(dir);
+                    return (pid_t)pid;
+                }
+            }
+            fclose(f);
+        }
+    }
+    closedir(dir);
+    return -1;
+}
+
+/**
+ * Get module base address in remote process
+ */
+uintptr_t get_module_base(pid_t pid, const char* module_name) {
+    char path[256];
+    char line[512];
+    uintptr_t base = 0;
+    snprintf(path, sizeof(path), "/proc/%d/maps", pid);
+    FILE* f = fopen(path, "r");
+    if (!f) return 0;
+    while (fgets(line, sizeof(line), f)) {
+        if (strstr(line, module_name)) {
+            base = strtoull(line, NULL, 16);
+            break;
+        }
+    }
+    fclose(f);
+    return base;
+}
+
+/**
+ * Core Injection Logic using PTRACE
+ */
+int inject_so(pid_t pid, const char* so_path) {
+    printf("[+] Target PID: %d\n", pid);
+    
+    // 1. Attach to process
+    if (ptrace(PTRACE_ATTACH, pid, NULL, NULL) < 0) {
+        perror("[-] PTRACE_ATTACH failed");
+        return -1;
+    }
+    waitpid(pid, NULL, WUNTRACED);
+    printf("[+] Attached successfully\n");
+
+    // 2. Backup registers
+    struct user_pt_regs regs, old_regs;
+    struct iovec iov = { .iov_base = &regs, .iov_len = sizeof(regs) };
+    ptrace(PTRACE_GETREGSET, pid, NT_PRSTATUS, &iov);
+    memcpy(&old_regs, &regs, sizeof(regs));
+
+    // 3. Locate remote dlopen (via linker64)
+    uintptr_t local_linker = get_module_base(getpid(), "linker64");
+    uintptr_t remote_linker = get_module_base(pid, "linker64");
+    
+    // Modern Android uses __loader_dlopen inside linker64
+    uintptr_t local_dlopen = (uintptr_t)dlsym(RTLD_DEFAULT, "__loader_dlopen");
+    if (!local_dlopen) {
+        local_dlopen = (uintptr_t)dlsym(RTLD_DEFAULT, "dlopen");
+    }
+    
+    uintptr_t remote_dlopen = local_dlopen - local_linker + remote_linker;
+    printf("[+] Calculated remote dlopen: %p\n", (void*)remote_dlopen);
+
+    // 4. Write SO path to remote stack
+    uintptr_t sp = regs.sp - 512; // Buffer area
+    size_t path_len = strlen(so_path) + 1;
+    for (size_t i = 0; i < path_len; i += 8) {
+        long data = 0;
+        memcpy(&data, so_path + i, (path_len - i) < 8 ? (path_len - i) : 8);
+        ptrace(PTRACE_POKETEXT, pid, sp + i, (void*)data);
+    }
+
+    // 5. Hijack registers to call dlopen(path, RTLD_NOW)
+    // ARM64 calling convention: x0 = arg0, x1 = arg1, pc = func, x30 = LR
+    regs.regs[0] = sp;                // x0: const char *filename
+    regs.regs[1] = RTLD_NOW;          // x1: int flag
+    regs.regs[30] = 0;                // LR: Return to null to trigger stop
+    regs.pc = remote_dlopen;          // PC: Jump to dlopen
+
+    ptrace(PTRACE_SETREGSET, pid, NT_PRSTATUS, &iov);
+
+    // 6. Resume and wait for finish
+    ptrace(PTRACE_CONT, pid, NULL, NULL);
+    waitpid(pid, NULL, WUNTRACED);
+
+    // 7. Restore registers and detach
+    iov.iov_base = &old_regs;
+    ptrace(PTRACE_SETREGSET, pid, NT_PRSTATUS, &iov);
+    ptrace(PTRACE_DETACH, pid, NULL, NULL);
+    
+    printf("[+] Injection cycle finished.\n");
+    return 0;
+}
+
+int main(int argc, char* argv[]) {
+    const char* target_pkg = "com.tencent.jkchess";
+    const char* so_to_inject = "/data/local/tmp/libJKMenu.so";
+
+    if (getuid() != 0) {
+        printf("[!] Please run as ROOT (su)\n");
+        return 1;
+    }
+
+    pid_t target_pid = find_pid(target_pkg);
+    if (target_pid == -1) {
+        printf("[-] Target %s not found. Open the game first.\n", target_pkg);
+        return 1;
+    }
+
+    if (inject_so(target_pid, so_to_inject) == 0) {
+        printf("[*] Done. Check the game screen for ImGui menu.\n");
+    } else {
+        printf("[!] Failed to inject.\n");
+    }
+    
+    return 0;
+}