This indicates an attack attempt against a Denial of Service vulnerability in Apple OS X.
The vulnerability is caused by an error when the vulnerable software handles a malicious tcp packet. It allows a remote attacker to crash vulnerable systems via a crafted tcp packet.
Apple iOS before 8.3
Apple OS X before 10.10.3
Apple TV before 7.2
Denial of Service: Remote attacker can crash vulnerable systems.
Refer to the vendor's advisory for updates: