Is the source address of the system logged a Cisco DSL router ?
Anyway the message is caused due to an ICMP packet "unknown type i.e could be a ping request or a route solicitation etc" falling on its Checksum on its return path.
So your system has sent a ICMP type "unknown" to that IP addresses as part of normal network operations.
The checksum when sent out was calculated from a 0, then the destination system reverses the checksum to get a 0 again, however it failed and got some other number flagging it up as corrupted. "this could also be your system flagging the inbound ICMP as corrupted I just don't know from that unhelpful error message"
It shouldn't be anyone trying to DOS you, as all packets would be dropped with a checksum that didn't conform to the RFC, it's more like a system / router messing up somewhere.