The syslog message was generated on a Linux 2.6 machine serving as an
OSSEC agent host. The Linux 2.6 machine is running Fedora Core 5.

I worked with this host because it is accessible from the outside and
it was being bombed with FTP login requests from a single, unknown
external IP.

I expect that this solution works out for all out hosts because we are
pretty much standardized on Linux 2.6 - both Fedora Core 5 and Centos
5 - if we were not standardized, I'd go crazy :)



On Oct 28, 2:34 pm, "dan (ddp)" <[email protected]> wrote:
> What type of system did your syslog message come from?
> What others did you test?
>
> Looks like an okay change to me.
>
> On Thu, Oct 28, 2010 at 1:22 PM, blacklight <[email protected]> wrote:
> > Hello Folks,
>
> > We noticed that rule 11109 failed to trigger the active response that
> > we had specified. We traced the failure of rule 11109 to trigger the
> > active response that we had specified in ossec.conf to to a syntax
> > error in the "ftpd-mac-failure" decoder in the decoder.xml file that
> > comes by default with the OSSEC 2.5.1 tarball.
>
> > Here below is the text of the "ftpd-mac-failure" decoder in the
> > decoder.xml file of the OSSEC 2.5.1 tarball:
>
> > <decoder name="ftpd-mac-failure">
> >  <parent>ftpd</parent>
> >  <prematch>^Failed authentication from: \S+ |</prematch>
> >  <prematch>^repeated login failures from </prematch>
> >  <regex offset="after_prematch">[(\d+.\d+.\d+.\d+)]$</regex>
> >  <order>srcip</order>
> > </decoder>
>
> > Here below is the text of the "ftpd-mac-failure" decoder in our
> > decoder.xml file
>
> > <decoder name="ftpd-mac-failure">
> >  <parent>ftpd</parent>
> >  <prematch>^Failed authentication from: \S+ |</prematch>
> >  <prematch>^repeated login failures from </prematch>
> > <!--
> >  <regex offset="after_prematch">[(\d+.\d+.\d+.\d+)]$</regex>
> > -->
> >  <regex offset="after_prematch">(\S+)</regex>
> >  <order>srcip</order>
> > </decoder>
>
> > Here below is the text of the syslog statement that will trigger rule
> > 11109:
> > Oct 27 17:53:00 omd ftpd[8538]: repeated login failures from
> > 226.226.226.226 () -- test by V.
>
> > 1. Note that running ossec-logtest using the syslog statement above
> > yields the following result for the version of "ftpd-mac-failure" in
> > decoder.xml of OSSEC 2.5.1:
>
> > [r...@wiggum etc]# ossec-logtest -f -D /tmp/ossectest-121509/ -c /tmp/
> > ossectest-121509/etc/ossec.conf
> > 2010/10/28 13:13:26 ossec-testrule: INFO: Reading local decoder file.
>
> > 2010/10/28 13:13:43 ossec-testrule: INFO: Started (pid: 4684).
> > ossec-testrule: Type one log per line.
>
> > Oct 27 17:53:00 omd ftpd[8538]: repeated login failures from
> > 226.226.226.226 () -- test by V.
>
> > **Phase 1: Completed pre-decoding.
> >       full event: 'Oct 27 17:53:00 omd ftpd[8538]: repeated login
> > failures from 226.226.226.226 () -- test by V.'
> >       hostname: 'omd'
> >       program_name: 'ftpd'
> >       log: 'repeated login failures from 226.226.226.226 () -- test
> > by V.'
>
> > **Phase 2: Completed decoding.
> >       decoder: 'ftpd'
> >                              <--- Note that srcip is missing
>
> > **Rule debugging:
> >    Trying rule: 1 - Generic template for all syslog rules.
> >       *Rule 1 matched.
> >       *Trying child rules.
> >    Trying rule: 5500 - Grouping of the pam_unix rules.
> >    Trying rule: 5700 - SSHD messages grouped.
> >    Trying rule: 5600 - Grouping for the telnetd rules
> >    Trying rule: 2100 - NFS rules grouped.
> >    Trying rule: 2701 - Ignoring procmail messages.
> >    Trying rule: 2800 - Pre-match rule for smartd.
> >    Trying rule: 5100 - Pre-match rule for kernel messages
> >    Trying rule: 5200 - Ignoring hpiod for producing useless logs.
> >    Trying rule: 2830 - Crontab rule group.
> >    Trying rule: 5300 - Initial grouping for su messages.
> >    Trying rule: 5400 - Initial group for sudo messages
> >    Trying rule: 9100 - PPTPD messages grouped
> >    Trying rule: 9200 - Squid syslog messages grouped
> >    Trying rule: 2900 - Dpkg (Debian Package) log.
> >    Trying rule: 2930 - Yum logs.
> >    Trying rule: 2931 - Yum logs.
> >    Trying rule: 7200 - Grouping of the arpwatch rules.
> >    Trying rule: 7300 - Grouping of Symantec AV rules.
> >    Trying rule: 7400 - Grouping of Symantec Web Security rules.
> >    Trying rule: 4300 - Grouping of PIX rules
> >    Trying rule: 12100 - Grouping of the named rules
> >    Trying rule: 13100 - Grouping for the smbd rules.
> >    Trying rule: 11400 - Grouping for the vsftpd rules.
> >    Trying rule: 11300 - Grouping for the pure-ftpd rules.
> >    Trying rule: 11200 - Grouping for the proftpd rules.
> >    Trying rule: 11500 - Grouping for the Microsoft ftp rules.
> >    Trying rule: 11100 - Grouping for the ftpd rules.
> >       *Rule 11100 matched.
> >       *Trying child rules.
> >    Trying rule: 11102 - File created via FTP
> >    Trying rule: 11103 - File deleted via FTP
> >    Trying rule: 11104 - User uploaded a file to server.
> >    Trying rule: 11105 - User downloaded a file to server.
> >    Trying rule: 11109 - Multiple FTP failed login attempts.
> >       *Rule 11109 matched.
>
> > **Phase 3: Completed filtering (rules).
> >       Rule id: '11109'
> >       Level: '10'
> >       Description: 'Multiple FTP failed login attempts.'
> > **Alert to be generated.
>
> > 2. Note that running ossec-logtest using the syslog statement above
> > yields the following result for our version of "ftpd-mac-failure":
>
> > [r...@wiggum ~]# ossec-logtest -f
> > 2010/10/28 12:28:17 ossec-testrule: INFO: Reading local decoder file.
> > 2010/10/28 12:28:17 ossec-testrule: INFO: Started (pid: 21521).
> > ossec-testrule: Type one log per line.
>
> > Oct 27 15:25:46 omd ftpd[8538]: repeated login failures from
> > 202.106.110.190 ()
>
> > **Phase 1: Completed pre-decoding.
> >       full event: 'Oct 27 15:25:46 omd ftpd[8538]: repeated login
> > failures from 202.106.110.190 () -- test by V.'
> >       hostname: 'omd'
> >       program_name: 'ftpd'
> >       log: 'repeated login failures from 202.106.110.190 ()  -- test
> > by V.'
>
> > **Phase 2: Completed decoding.
> >       decoder: 'ftpd'
> >       srcip: '202.106.110.190'         <--- Note that srcip is
> > captured
>
> > **Rule debugging:
> >    Trying rule: 1 - Generic template for all syslog rules.
> >       *Rule 1 matched.
> >       *Trying child rules.
> >    Trying rule: 5500 - Grouping of the pam_unix rules.
> >    Trying rule: 5700 - SSHD messages grouped.
> >    Trying rule: 5600 - Grouping for the telnetd rules
> >    Trying rule: 2100 - NFS rules grouped.
> >    Trying rule: 2550 - rshd messages grouped.
> >    Trying rule: 2701 - Ignoring procmail messages.
> >    Trying rule: 2800 - Pre-match rule for smartd.
> >    Trying rule: 5100 - Pre-match rule for kernel messages
> >    Trying rule: 5200 - Ignoring hpiod for producing useless logs.
> >    Trying rule: 2830 - Crontab rule group.
> >    Trying rule: 5300 - Initial grouping for su messages.
> >    Trying rule: 5400 - Initial group for sudo messages
> >    Trying rule: 9100 - PPTPD messages grouped
> >    Trying rule: 9200 - Squid syslog messages grouped
> >    Trying rule: 2900 - Dpkg (Debian Package) log.
> >    Trying rule: 2930 - Yum logs.
> >    Trying rule: 2931 - Yum logs.
> >    Trying rule: 7200 - Grouping of the arpwatch rules.
> >    Trying rule: 7300 - Grouping of Symantec AV rules.
> >    Trying rule: 7400 - Grouping of Symantec Web Security rules.
> >    Trying rule: 4300 - Grouping of PIX rules
> >    Trying rule: 12100 - Grouping of the named rules
> >    Trying rule: 13100 - Grouping for the smbd rules.
> >    Trying rule: 11400 - Grouping for the vsftpd rules.
> >    Trying rule: 11300 - Grouping for the pure-ftpd rules.
> >    Trying rule: 11200 - Grouping for the proftpd rules.
> >    Trying rule: 11500 - Grouping for the Microsoft ftp rules.
> >    Trying rule: 11100 - Grouping for the ftpd rules.
> >       *Rule 11100 matched.
> >       *Trying child rules.
> >    Trying rule: 11102 - File created via FTP
> >    Trying rule: 11103 - File deleted via FTP
> >    Trying rule: 11104 - User uploaded a file to server.
> >    Trying rule: 11105 - User downloaded a file to server.
> >    Trying rule: 11109 - Multiple FTP failed login attempts.
> >       *Rule 11109 matched.
>
> > **Phase 3: Completed filtering (rules).
> >       Rule id: '11109'
> >       Level: '10'
> >       Description: 'Multiple FTP failed login attempts.'
> > **Alert to be generated.
>
> > I suggest that you fix the syntax of ftpd-mac-failure" the way we did
> > so as to actually capture the srcip parameter.

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