High CPU due to dispatch unit process in cisco ASA 5520

[anoop verma]

dispatch unit process using almost 100% CPU; frequency of the incident is 2 hours; FW get hanged and after removing the cable from FW, it get stable; again same after 2 hours;

hardware:- asa 5520

topology:- 

SW 2960----------FW5520_______asr1002

tcp connection sudennely increases to 5K, under normal condition it was less than 100;

Kindly share resolution steps;

[Mohammed al Baqari]

Check if you are under attack.

get the output of show perfmon

[anoop verma]

yes, as per my observation its a dos attack; few host(like 10.x.y.20) establishing tcp connection with 10.x.y.255 over port number 445; after scan that host 20 virus found; i want to isolate this;

[Mohammed al Baqari]

Ok. Attack on 445 isn't good. You should imlpment wannaCry ACLs
immediately.

[anoop verma]

pls share configuration;