If a lot of attacks come from AS44477, why not just block it?
We were seeing a lot of brute force/spraying password attempts from AS44477 a month or two ago, the setup looked fishy enough that it was easier to block the whole AS than waste time with it.
(And it's surprisingly large - ~1550 x /24 - at current market rates that IP space is probably worth something around $10-20 million).