Some syslog event IDs related to AnyConnect on cisco ASA

302013 - built inbound connection

302014 - teardown TCP connection

725012 - Device chooses cipher for the SSL session with peer interface

725008 - ssl client propose cipher

725007 - teardown new ssl connection / terminated

725001 - starting ssl handsharek

725002 - ssl handsake completed

725003 - request to resume

113005 - AAA user authentication rejected

http://www.cisco.com/en/US/docs/security/asa/asa82/system/message/logmsgs.html#wp4776913

716001 - anyconnect when user logs on

716002 - anyconnect when user logs off

Each connection that passes through the ASA is 9 syslogs so that will be a lot of logs

Old TAC sec pod cast

https://community.cisco.com/t5/security-knowledge-base/tac-security-podcast-show-information-and-episode-listing/ta-p/3126414

General syslog tips

Text zip's up well so you can zip before sending

Knowing the time frame of the issue helps any source / destination IPs

Notepad++ / sublime are good for working with big files

For really big files we really want a linux box

For windows users you can run a VM as well or install cygwin

User grep to look for sev1 events

grep "ASA-1-" ASASYSLOG.txt

Looks for sev 6 and pipe to head 

grep "ASA-6" ASAlogs.txt | head -n 3

-v can be used to remove items from the log

grep "ASA-6" ASAlogs.txt | grep -v "ASA-6-302011" | grep -v "ASA-6-302015" | head -n 3

We can build up our command adding more -v items

grep "ASA-6" ASAlogs.txt | grep -v "ASA-6-302011" | grep -v "ASA-6-302015" | grep -v "ASA-6-305011" | head -n 3

Other linux CLI tools that are very useful

count / sed / awk / uniq / sort / bc

To remove all the charactors on the line leading up to "Mar 28",  use the sed program to find and replace that text with "nothing":

cat ASAlogs.txt | sed 's/^.*Mar 28/Mar 28/g' | head -n 4

cut can be used to display something specific from each line:

grep "ASA-6-305011" ASAlogs.txt  | cut -f 13 -d ' '

<166>Mar 28 2013 08:22:50: %ASA-6-305011: Built dynamic TCP translation from inside:10.10.103.38/63894 to outside:192.168.124.149/63894

becomes

outside:192.168.124.149/61128

Now lets say you wanted to get rid of the 'outside' text at the start of each line. Use sed to replace that text with nothing:

grep "ASA-6-305011" ASAlogs.txt  | cut -f 13 -d ' ' | sed 's/outside://g'

When connection is torn down (teardown event) there is a byte count included

You could look for the initiator and the byte count

IP and how many bytes transfer

Then sort that based on byte count

This would give you talker

Sort by IP addresses 

Use bc to sum up all the ip and sort on byte counts and see which IP was the top talker over all

You could also work on top number of connections. Look for usernames instead of IP's etc. A ddos may make a lot of connections but small amount of data transfered 

You could look at denied connections