Hello But I am using OSSEC agent that downloaded from OSSEC. And configured it to send dhcp logs, so my assumption was that this shall somehow stick together on OSSEC server ? Or maybe there is a mistake in configuration for DHCP logs and different format shall be selected ?
Now I have in ossec.conf for agent : <localfile> <location>C:\Windows\sysnative\dhcp\DhcpSrvLog-%a.log</location> <log_format>syslog</log_format> </localfile> If I do not want change decoder.xml and have permeant solution not affected by updates - what could be a proposal ? Copy chapter for ms-dhcp from decoder.xml to local_decoder.xml, rename it in some way and add right prematch ? Current is : <decoder name="ms-dhcp-ipv4"> <prematch>^\d\d,\d+/\d+/\d\d\d\d,\d+:\d+:\d+,|</prematch> <prematch>^\d\d,\d+/\d+/\d\d,\d+:\d+:\d+,</prematch> <regex>^(\d\d),\d+/\d+/\d\d\d*,\d+:\d+:\d+,(\.+),(\d+.\d+.\d+.\d+)</regex> <order>id,extra_data,srcip</order> </decoder> Many thanks, Martynas -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of dan (ddp) Sent: Tuesday, December 9, 2014 5:49 PM To: [email protected] Subject: Re: [ossec-list] MS Windows server DHCP logs On Tue, Dec 9, 2014 at 10:19 AM, Martynas Buožis <[email protected]> wrote: > Hello > > Yes, message is from archives.log as it was sent by ossec-agent from server. > But I never got it parsed into alerts.log. > > If I will change decoder.xml - will it be overwritten with a next update ? Yes. > > I was expecting that standard logs as sent by OSSEC agent should be handled > by default OSSEC server definitions .... > According to my tests it is. It is decoded by ms-dhcp-ipv4, and triggers rule 6300 (Grouping for the MS-DHCP rules). Try running the log message through ossec-logtest without the header that OSSEC adds. > Many thanks for an advice, > Martynas > > >> On 09 Dec 2014, at 14:53, dan (ddp) <[email protected]> wrote: >> >>> On Tue, Dec 9, 2014 at 7:44 AM, dan (ddp) <[email protected]> wrote: >>>> On Tue, Dec 9, 2014 at 6:59 AM, Martynas Buožis <[email protected]> wrote: >>>> Hello >>>> >>>> I have following in my ossec.conf file on Windows server : >>>> >>>> <localfile> >>>> <location>C:\Windows\sysnative\dhcp\DhcpSrvLog-%a.log</location> >>>> <log_format>syslog</log_format> </localfile> >>>> >>>> Messages are coming as enabled in full log (command : logs/archives# tail >>>> -f archives.log | grep dhcp) and look like : >>>> >>>> 2014 Dec 09 13:49:45 (PDC) >>>> 192.168.100.1->\Windows\sysnative\dhcp\DhcpSrvLog-Tue.log >>>> 30,12/09/14,13:48:57,DNS Update >>>> Request,192.168.101.71,host.domain.local,,,0,6,,,,,,,,,0 >>>> >>>> PDC is server name, 192.168.100.1 is server IP. >>>> >>>> But above message is not recognized by decoder and is not handled by >>>> ms_dhcp_rules.xml. >>>> >>>> ossec-testrule: Type one log per line. >>>> >>>> 2014 Dec 09 13:49:45 (PDC) >>>> 192.168.100.1->\Windows\sysnative\dhcp\DhcpSrvLog-Tue.log >>>> 30,12/09/14,13:48:57,DNS Update >>>> Request,192.168.101.71,host.domain.local,,,0,6,,,,,,,,,0 >>>> >>>> >>>> **Phase 1: Completed pre-decoding. >>>> full event: '2014 Dec 09 13:49:45 (PDC) >>>> 192.168.100.1->\Windows\sysnative\dhcp\DhcpSrvLog-Tue.log >>>> 30,12/09/14,13:48:57,DNS Update >>>> Request,192.168.101.71,host.domain.local,,,0,6,,,,,,,,,0' >>>> hostname: 'ossec' >>>> program_name: '(null)' >>>> log: '2014 Dec 09 13:49:45 (PDC) >>>> 192.168.100.1->\Windows\sysnative\dhcp\DhcpSrvLog-Tue.log >>>> 30,12/09/14,13:48:57,DNS Update >>>> Request,192.168.101.71,host.domain.local,,,0,6,,,,,,,,,0' >>>> >>>> **Phase 2: Completed decoding. >>>> No decoder matched >>>> >>>> >>>> How I can fix that so OSSEC will recognize above message for DHCP ? >>> >>> What version of Windows is this? The logs don't look anything like >>> the samples we have for 2008 (2003?). >> >> Ooooh, I think I see an issue. Did the log sample you provided come >> from archives.log? If so, it has a header on it "2014 Dec 09 13:49:45 >> (PDC) 192.168.100.1->\Windows\sysnative\dhcp\DhcpSrvLog-Tue.log ." >> Remove this header and you have a proper log message. >> >> If that log message didn't come from archives.log, find out why it's >> adding that header onto the message, or modify the decoder.xml to >> handle it (it's a 5 minute change). >> >>>> Many thanks for an advise. >>>> >>>> >>>> With best regards >>>> Martynas >>>> >>>> -- >>>> >>>> --- >>>> You received this message because you are subscribed to the Google Groups >>>> "ossec-list" group. >>>> To unsubscribe from this group and stop receiving emails from it, send an >>>> email to [email protected]. >>>> For more options, visit https://groups.google.com/d/optout. >> >> -- >> >> --- >> You received this message because you are subscribed to the Google Groups >> "ossec-list" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> For more options, visit https://groups.google.com/d/optout. > > -- > > --- > You received this message because you are subscribed to the Google Groups > "ossec-list" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/d/optout. -- --- You received this message because you are subscribed to the Google Groups "ossec-list" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout. -- --- You received this message because you are subscribed to the Google Groups "ossec-list" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
