If it’s just the dirty flag (it was uncleanly unmounted) you can try
ntfsfix -d /dev/sdc1
Still probably better to boot into Windows and let it deal with it (ntfs tools are still reverse engineered stuff after all), and check journalctl before doing it, but it works in a pinch.
Even IT people don’t give a shit about security until it’s way too late. Source: getting out of a job where the median age of a server is around 3-4 years old with no updates and runtimes hard installed outside repositories.