Created a script to get the connections every time a new node connected. Everything looked normal in the peer list until I saw many nodes from:
100.42.27.* (around 200 peers)
193.142.59.* (around 200 peers)
199.116.84.* (around 100 peers)
209.222.252.* (around 150 peers)
91.198.115.* (around 150 peers)
The 100.42.27., 199.116.84., 209.222.252., and 91.198.115. all belong to “Lionlink Networks”.
These are around 600 nodes that are under that ISP and account for 20-30% of all nodes seen from a 3 day survey span.
This looks suspicious to me and the massive amounts of nodes raises many red flags and does not look natural at all.
If these were malicious, in concept, with the 13 default IN/OUT peers, if all connected are malicious, the innocent one would have no other data to compare it to.
(Edit: Updated Theory: having many nodes has the ability trace transactions and block miners easier based on timing attack)
MRL has recently noticed the same issue and is discussing solutions: https://github.com/monero-project/research-lab/issues/126
yea and all above IP ranges are found at the top of https://github.com/Boog900/monero-ban-list/blob/main/ban_list.txt. The ban list is good but it is not enabled by default.
100.42.27.* is banned on the one above but not the official monero ban list indicating new malicious subnets appearing.