Rating:

1. Use `binwalk -e` to extract content of `Setup.exe`
1. Again use `binwalk -e` on `meta-activity-monitor-1.0.0-full.nupkg`
1. Main app payload can be found under `meta-activity-monitor-1.0.0-full.nupkg.extracted/lib/net45/resources/app.asar`
1. `strings` on `app.asar` reveals:

```sh
// THE FL@G is right below this message!!
let f = "TWV0YUNURnt5b3VfY29tcGxldGVkX0FfU2VhcmNoX0FuZF9SZXNjdWVfdGhlX2ZsYWdfbWlzc2lvbn0="
```

1. Decode base64 encoded string

```sh
$ echo "TWV0YUNURnt5b3VfY29tcGxldGVkX0FfU2VhcmNoX0FuZF9SZXNjdWVfdGhlX2ZsYWdfbWlzc2lvbn0=" | base64 -D
$ MetaCTF{you_completed_A_Search_And_Rescue_the_flag_mission}
```