Looks like you have an issue with VPN client 3 per the log file. Starts with this line:not sure how to translate
but
Jun 8 around 1400
Jun 8 14:01:07 rc_service: httpd 1852:notify_rc start_vpnclient3
So, what is VPN client 3? Do you have a VPN Client 3 enabled? If so who does VPN Client 3 connect to? Does anyone else have access to the router? Are the WiFi networks locked down with secure passwords? Are any rogue network clients connected via wired LAN or WiFi?
If the router has been compromised you should remove any attached USB hard drive, then do a hard factory reset and then do a manual configuration (do not import a previously saved router CFG file). If you use a USB drive on the router may want to check that drive (or erase, repartition and reformat it) in case it has been compromised. Edit: One may want to reflash the latest Asus or Asus Merlin firmware just in case.