this task is a total brute force attack using fcrackzip and the rockyou Dictionary. so we have just to write a litle script and w4i7 f0r th3 fL4g , i used a php script executed with shell cuz i am familiarised with the lovely php tech , soooo:
```
#!/usr/bin/php
=0;$i--)
{
echo $i;
$x=shell_exec("fcrackzip -D -p ../zip/rockyou.txt -u ../zip/zipfile_'$i'.zip");
$y=substr($x,28,strlen($x)-29);
echo strlen($y);
echo $y;
echo $i;
$x=shell_exec("unzip -P '$y' ../zip/zipfile_'$i' -d ../zip/");
echo $x;
}

?>
```

and we get the flag : d4rk{7h1s_w0uldve_t4k3n_s0m3_t1m3}c0de