full_command netstat and other output in alerts.log file

[Marcin Liszka]

Hallo every body

I have a question. I need to monitor runnig services on ossec agents (Ossec version 2.7.1).  I found the problem in ossec server that the output from full_command (system command for example is "netstat -ntlp" or "chckconfig") is truncated in alerts.log file.

in alerts.log ther is no full output from the command netstat and their previus state. So administrator can't check what was changed in the system from alert arrived.

Is it posible to change it (alert body size or something similar variable)??? Is there any solution to see full information in alerts.log like in /var/ossec/diff/[hostname]/[rule_id]/ folder???

Thanks for any idea

[Kevin Kelly]

This is what I am using:

cat netstat_filter.sh

awk '$NF != "LISTEN" || $4 ~ /^127\.0\.0\./ { next } { n = split($4, wk, ":" ) } { in_use[wk[n]] = 1 } END { for ( port in in_use ) { printf("%d\n", port) } }' | sort -n | sed -e :a -e N -e 's/\n/ /' -e ta

netstat -tan | /netstat_filter.sh

22 25 80 111 443 662 10050 20031 45525

<localfile>

    <log_format>full_command</log_format>

    <command>netstat -tan | /netstat_filter.sh</command>

</localfile>

--
Kevin Kelly
Director, Network Technology
Whitman College

---

From: "Marcin Liszka" <mak...@gmail.com>
To: ossec...@googlegroups.com
Sent: Thursday, January 16, 2014 10:20:33 AM
Subject: [ossec-list] full_command netstat and other output in alerts.log file

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[Devon J. Greene]

Kevin,

 

I like your approach in keeping a filter on the host machine to specify the output expected (the listening ports) as opposed to trying to modify OSSEC itself. Not sure if we have a community filter like this for windows but I wouldn’t mind writing a powershell version of this for windows and posting to the group.

 

Devon J. Greene

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[BP9906]

The full output should be in a folder. Ive seen it before just dont recall where.

[Devon J. Greene]

All,

Following up with a windows powershell version for this. You pass it the netstat -nao command and it will filter out the listening ports and return them in a list of tuples ex: [(protocol,ipaddress,port),(protocol,ipaddress,port)]. I can further expand on this to include the actual program name, but for now I'm good with just knowing what ports are listening.

Save as netstatParser.ps1 >>
param(
[Parameter(ValueFromPipeline=$true,Position=0)] [string] $Data
)

$Data = $input
$ossec_out = "["

foreach ($line in $input)
{
if ($line -match "(TCP|UDP)\s+([^:]*):(\d+).*LISTENING")
{
$var = "($($matches[1]),$($matches[2]),$($matches[3])),"
$ossec_out += $var
}
}

$ossec_out += "]"
$ossec_out = $ossec_out.replace(",]","]")
write-output $ossec_out
<<

Example usage with full command:
Netstat -nao | .\parseNetstat.ps1

Output Example:
[(TCP,0.0.0.0,135),(TCP,0.0.0.0,445),(TCP,0.0.0.0,2701),(TCP,0.0.0.0,3389),(TCP,0.0.0.0,5985),(TCP,0.0.0.0,7561),(TCP,0.0.0.0,45329),(TCP,0.0.0.0,47001),(TCP,0.0.0.0,49152),(TCP,0.0.0.0,49153),(TCP,0.0.0.0,49154),(TCP,0.0.0.0,49177),(TCP,0.0.0.0,49178),(TCP,0.0.0.0,49183),(TCP,127.0.0.1,55578),(TCP,192.168.222.210,139)]

Again thanks Kevin for the inspiration

Devon J. Greene

PS Pardon my cruddy powershell, it's not really my cup of tea ha.

-----Original Message-----
From: ossec...@googlegroups.com [mailto:ossec...@googlegroups.com] On Behalf Of BP9906
Sent: Friday, January 17, 2014 7:06 AM
To: ossec...@googlegroups.com
Subject: [ossec-list] full_command netstat and other output in alerts.log file