This Article explains the meaning of below logs messages.
Jun 20 09:31:12 router-1 rpd[28711]: %DAEMON-3: Received malformed update from x.x.x.x (Internal AS 10009)
Jun 20 09:31:12 router-1 rpd[28711]: %DAEMON-3: Malformed Attribute AGGREGATOR(7) flag 0xc0 length 8 error 14 (Malformed aggregator ASN).
Customer would receive below logs message in the syslogs.
This log message means that a BGP update is received from the peer with an incorrect aggregator attribute here (0.0.0.0).According to rfc7606, An UPDATE message with a malformed AGGREGATOR attribute SHALL be handled using the approach of "attribute discard".
So you can ignore this message if this has come only once as this could probably some bad route which was discarded anyways. If the message is coming frequently you can enable bgp traceoption which gives more details about the aggregator router and then you can check that router as to why it is sending route updates with bad attribute.
BGP Traces show that 0 ASN is received from Peer: Apr 24 13:05:31.815628 BGP RECV x.x.x.x+179 -> x.x.x.x+63183 Apr 24 13:05:31.815637 BGP RECV message type 2 (Update) length 78 Apr 24 13:05:31.815646 BGP RECV Update PDU length 78 Apr 24 13:05:31.815655 BGP RECV flags 0x40 code Origin(1): IGP Apr 24 13:05:31.815673 BGP RECV flags 0x40 code ASPath(2) length 22: 10069 10068 10067 10066 10065 Apr 24 13:05:31.815682 BGP RECV flags 0x40 code NextHop(3): x.x.x.x Apr 24 13:05:31.815692 BGP RECV flags 0xc0 code Aggregator(7): 0 0.0.0.0 <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< Apr 24 13:05:31.815701 End-of-Attributes Apr 24 13:05:31.815719 BGP RECV x.x.x.x/23 , x.x.x.x/23 Apr 24 13:05:31.815751 bgp_rcv_nlri: Peer x.x.x.x (External AS 69) Apr 24 13:05:31.815764 bgp_rcv_nlri: x.x.x.x/23