diff --git a/4/level4/flag.txt b/4/level4/flag.txt
new file mode 100644
index 0000000..edd5b55
--- /dev/null
+++ b/4/level4/flag.txt
@@ -0,0 +1 @@
+hacklab{thanks_mario_but_the_flag_is_on_another_server}
diff --git a/4/level4/input.txt b/4/level4/input.txt
new file mode 100644
index 0000000..55f585f
Binary files /dev/null and b/4/level4/input.txt differ
diff --git a/4/level4/level4 b/4/level4/level4
new file mode 100755
index 0000000..e8ea7cc
Binary files /dev/null and b/4/level4/level4 differ
diff --git a/4/level4/level4.c b/4/level4/level4.c
new file mode 100644
index 0000000..02caac9
--- /dev/null
+++ b/4/level4/level4.c
@@ -0,0 +1,19 @@
+// gcc -o level4 -no-pie -fno-stack-protector level4.c
+#include <stdio.h>
+#include <stdlib.h>
+
+const char command[] = "/bin/sh";
+
+void win(const char *cmd) { system(cmd); }
+
+int main(int argc, char **argv) {
+  // Disable output buffering. Not part of the challenge.
+  setvbuf(stdout, NULL, _IONBF, 0);
+  setvbuf(stdin, NULL, _IONBF, 0);
+
+  char buffer[32];
+  puts("What do you want to talk about?");
+  fgets(buffer, 320, stdin);
+  puts("Bye.");
+  return 0;
+}