diff --git a/.gitignore b/.gitignore
index 348204b..42ee0b9 100755
--- a/.gitignore
+++ b/.gitignore
@@ -5,6 +5,7 @@
 *.obj
 *.pdb
 *.ilk
+*.log
 
 build/
 plugins_install/
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..122e075
--- /dev/null
+++ b/README.md
@@ -0,0 +1,24 @@
+# windows-binary-fuzzing
+
+## API methods
+
+- [ ] `GetOpenFileNameA`
+- [ ] `IFileOpenDialog`
+- [ ] `QFileDialog::getOpenFileName`
+- [ ] `wxFileDialog`
+
+## Build commands (client)
+
+```bash
+mkdir build
+cmake -DDynamoRIO_DIR=C:\Users\vboxuser\DynamoRIO-Windows\cmake ..
+cmake --build .
+```
+
+## Execution commands (drrun)
+
+e.g.
+
+```bash
+drrun -c ..\..\clients\mov_to_nop\build\Debug\mov_to_nop.dll -c C:\Users\vboxuser\git\winafl\build64\bin\Release\winafl.dll -debug -target_offset 0x8530 -fuzz_iterations 1 -nargs 2 -target_module Twice.exe -- .\Twice.exe
+```
\ No newline at end of file
diff --git a/clients/GetOpenFileNameA/CMakeLists.txt b/clients/GetOpenFileNameA/CMakeLists.txt
new file mode 100644
index 0000000..eae5a07
--- /dev/null
+++ b/clients/GetOpenFileNameA/CMakeLists.txt
@@ -0,0 +1,7 @@
+cmake_minimum_required(VERSION 3.7)
+project(GetOpenFileNameA)
+
+find_package(DynamoRIO REQUIRED)
+add_library(GetOpenFileNameA SHARED main.c)
+target_link_libraries(GetOpenFileNameA drwrap drmgr)
+configure_DynamoRIO_client(GetOpenFileNameA)
diff --git a/clients/GetOpenFileNameA/main.c b/clients/GetOpenFileNameA/main.c
new file mode 100644
index 0000000..521354e
--- /dev/null
+++ b/clients/GetOpenFileNameA/main.c
@@ -0,0 +1,94 @@
+#include "dr_api.h"
+#include "dr_ir_opnd.h"
+#include "dr_ir_instr.h"
+#include "dr_ir_opcodes_x86.h"
+#include "dr_ir_macros_x86.h"
+
+#include <ctype.h>
+#include <string.h>
+#include <windows.h>
+#include <commdlg.h>
+
+char *CUSTOM_FILE = "C:\\Users\\vboxuser\\Downloads\\spoofed_number.txt";
+
+static app_pc pc_GetOpenFileNameA = NULL;
+
+static void intercept_GetOpenFileNameA() {
+    // dr_printf("intercept_GetOpenFileNameA(...)\n");
+
+    void *drcontext = dr_get_current_drcontext();
+
+    dr_mcontext_t mcontext = { sizeof(mcontext), DR_MC_ALL };
+    dr_get_mcontext(drcontext, &mcontext);
+
+    OPENFILENAME *ofn = (OPENFILENAME *)mcontext.rcx;
+    // dr_printf("OPENFILENAME at %p\n", ofn);
+
+    for (int i = 0; i < strlen(CUSTOM_FILE); i++) ofn->lpstrFile[i] = CUSTOM_FILE[i];
+    ofn->lpstrFile[strlen(CUSTOM_FILE)] = 0;
+
+    mcontext.rax = 1;
+
+    dr_set_mcontext(drcontext, &mcontext);
+}
+
+static void event_exit(void) {
+    // dr_printf("Exiting custom DynamoRIO client...\n");
+}
+
+static void event_module_load(void *drcontext, const module_data_t *mod, bool loaded) {
+    char lowerpath[MAX_PATH];
+    strcpy(lowerpath, mod->full_path);
+    for (int i = 0; i < strlen(lowerpath); i++) {
+        lowerpath[i] = tolower(lowerpath[i]);
+    }
+
+    if (strstr(lowerpath, "comdlg32.dll")) {
+        pc_GetOpenFileNameA = (app_pc)dr_get_proc_address(mod->handle, "GetOpenFileNameA");
+        // if (pc_GetOpenFileNameA) dr_printf("Found GetOpenFileNameA at %p\n", pc_GetOpenFileNameA);
+    }
+}
+
+
+static dr_emit_flags_t event_basic_block(void *drcontext, void *tag, instrlist_t *bb, bool for_trace, bool translating) {
+    instr_t *to_remove = NULL, *instr = instrlist_first(bb);
+    while (instr) {
+        instr_t *next = instr_get_next(instr);
+
+        app_pc target = NULL;
+
+        if (instr_is_call_direct(instr)) {
+            app_pc target = instr_get_branch_target_pc(instr);
+        } else if (instr_is_call_indirect(instr)) {
+            opnd_t opnd = instr_get_src(instr, 0);
+            if (opnd_is_memory_reference(opnd)) {
+                app_pc addr = opnd_compute_address(opnd, drcontext);
+                if (addr) dr_safe_read(addr, sizeof(app_pc), &target, NULL);
+            }
+        }
+
+        if (target == pc_GetOpenFileNameA) {
+            // dr_printf("Call to GetOpenFileNameA detected at %p\n", instr_get_app_pc(instr));
+
+            dr_insert_clean_call(drcontext, bb, instr, (void *)intercept_GetOpenFileNameA, false, 0);
+
+            instrlist_remove(bb, instr);
+            instr_destroy(drcontext, instr);
+            instr = next;
+        }
+
+        instr = next;
+    }
+    
+    return DR_EMIT_DEFAULT;
+}
+
+DR_EXPORT void dr_client_main(client_id_t id, int argc, const char *argv[]) {
+    // dr_printf("Loading custom DynamoRIO client...\n");
+    dr_set_client_name("Custom DynamoRIO client", "https://gitea.cloud.lehnert.dev/ludwig/windows-binary-fuzzing");
+    dr_register_exit_event(event_exit);
+    dr_register_module_load_event(event_module_load);
+    dr_register_bb_event(event_basic_block);
+    // dr_printf("Custom DynamoRIO client loaded.\n");
+}
+
diff --git a/clients/build_all.ps1 b/clients/build_all.ps1
new file mode 100755
index 0000000..e8cc20b
--- /dev/null
+++ b/clients/build_all.ps1
@@ -0,0 +1,17 @@
+$CWD = (pwd).Path
+
+$DIR = $PSScriptRoot
+cd $DIR
+
+Get-ChildItem -Directory | % {
+    $clientDir = "$DIR\$_"
+    $buildDir = "$DIR\$_\build"
+
+    $$ = New-Item -ItemType Directory -Force $buildDir
+    cd $buildDir
+
+    cmake -DDynamoRIO_DIR=C:\Users\vboxuser\DynamoRIO-Windows\cmake ..
+    cmake --build .
+}
+
+cd $CWD
diff --git a/clients/mov_to_nop/CMakeLists.txt b/clients/mov_to_nop/CMakeLists.txt
deleted file mode 100644
index b4ac465..0000000
--- a/clients/mov_to_nop/CMakeLists.txt
+++ /dev/null
@@ -1,6 +0,0 @@
-cmake_minimum_required(VERSION 3.7)
-project(mov_to_nop)
-
-find_package(DynamoRIO REQUIRED)
-add_library(mov_to_nop SHARED mov_to_nop.c)
-configure_DynamoRIO_client(mov_to_nop)
diff --git a/clients/mov_to_nop/mov_to_nop.c b/clients/mov_to_nop/mov_to_nop.c
deleted file mode 100644
index f67cdba..0000000
--- a/clients/mov_to_nop/mov_to_nop.c
+++ /dev/null
@@ -1,26 +0,0 @@
-#include "dr_api.h"
-#include "dr_ir_opcodes_x86.h"
-
-static dr_emit_flags_t event_basic_block(void *drcontext, void *tag,
-                                         instrlist_t *bb, bool for_trace, bool translating);
-
-DR_EXPORT void dr_client_main(client_id_t id, int argc, const char *argv[]) {
-    dr_set_client_name("MOV-to-NOP Client (No drmgr)", "https://dynamorio.org/");
-    dr_register_bb_event(event_basic_block);
-    dr_printf("MOV-to-NOP client loaded (no drmgr).\n");
-}
-
-static dr_emit_flags_t event_basic_block(void *drcontext, void *tag,
-                                         instrlist_t *bb, bool for_trace, bool translating) {
-    for (instr_t *instr = instrlist_first_app(bb);
-         instr != NULL;
-         instr = instr_get_next_app(instr)) {
-
-        int opcode = instr_get_opcode(instr);
-        if (opcode == OP_mov_st || opcode == OP_mov_ld) {
-            instr_set_opcode(instr, OP_nop);
-        }
-    }
-
-    return DR_EMIT_DEFAULT;
-}
diff --git a/programs/Makefile b/programs/Makefile
index 50dcc9d..3e2da7d 100644
--- a/programs/Makefile
+++ b/programs/Makefile
@@ -7,10 +7,10 @@ clean:
 	del /Q "compiled\*"
 
 compiled\Foo.exe: source\Foo.c
-	$(CC) /Fe:$@ source\Foo.c comdlg32.lib $(CFLAGS)
+	$(CC) /Fe:$@ source\Foo.c $(CFLAGS)
 
 compiled\Twice.exe: source\Twice.c
 	$(CC) /Fe:$@ source\Twice.c comdlg32.lib $(CFLAGS)
 
 compiled\JustOpen.exe: source\JustOpen.c
-	$(CC) /Fe:$@ source\JustOpen.c comdlg32.lib $(CFLAGS)
\ No newline at end of file
+	$(CC) /Fe:$@ source\JustOpen.c comdlg32.lib $(CFLAGS)