How do I report INVISIBLE bots?

[MStowastiqVahlshdeh]

File a report by using the in-game command [System Menu] -> [Support Desk] -> [Contact Us] -> [Report Cheating]
It gives info on what each category means. You can also screencap the image, loc and name of the botter and report it to the support website later if you don't want to report in game. If you can't click on their name then you can at least type /echo <pos> to get the location you saw it in your chatlog, record the time and report what you saw in detail.

Whether or not we can see them, the STF can see them and likely it is a place they will return to do whatever they are doing so reporting it will allow the STF to locate hotspots for this kind of thing. Here is the most recent ban report, came out today:
Regarding Actions Taken Against In-Game RMT and Other Illicit Activities (Jan. 16)

- Accounts receiving disciplinary action for illicit activity: 462