base64 encoded sextorsion

[Brent Clark]

Good day Guys

I would like to ask it someone could help write a rule for the following 
base64 encoded sextorsion.

https://pastebin.com/raw/MWYmfkuh

I tried using rawbody. But it was proving to not work and be the right 
solution. Below is it me testing.

i.e.
body     BASESEX /8J2XrvCdmIHwnZiB8J2XsvCdl7vwnZiB8J2XtvCdl7zwnZe7/
describe BASESEX Base64 Sextorsion
score    BASESEX 2.0

If anyone could assist, it would be appreciated.

King regards
Brent Clark