Hmm ok...so wait i can guarantee any tampering gets detected as the
md5sum and sha1sum changes...BUT its not detected in real time.
I'll look into this tomorrow if u dont mind. I have a couple of issues
with the WUI---
FYI im Gurtaj
xD


On Mar 7, 2:48 pm, Gurtaj Singh <gurtaj.si...@esentire.com> wrote:
> Yea I know what u mean.
> But a couple of days ago i modified a file(I think it was the /etc/group
> file)...syscheck fired a lvl 7 alert like 2 min later...it detected a
> modified file...havent tried a reduced logfile yet.
> also can u tell me what log file did u use?
>
> On Mon, 2011-03-07 at 13:31 -0600, Nate Woodward wrote:
>
> > > -----Original Message-----
> > > From: gutsy gibbon [mailto:gibbongutsy...@gmail.com]
> > > Sent: Monday, March 07, 2011 12:52 PM
> > > To: ossec-list
> > > Subject: [ossec-list] Re: Deletion of log data
>
> > > what log file did u open with vim...make sure that the log
> > > file u open is included in the ossec.conf file and just to
>
> > I made sure I was modifying a logfile that is being monitored.
>
> > > make sure the rule works reduce the 6 hr syscheck thing...get
> > > it to run right after u edit the file..
>
> > I'll give this a try, but assuming the rule does work (it's one of the
> > rules that ships with OSSEC, after all), how do I make sure log
> > tampering will be detected no matter what? The OSSEC book says the time
> > between syschecks has a minimum frequency of an hour, and I can't
> > exactly ask crackers to only tamper with my logs X minutes after the top
> > of the hour.
>
> > > On Mar 6, 10:54 am, "Tanishk Lakhaani" <tanishk2...@gmail.com> wrote:
> > > > I think it checks for the same only at the time of running
> > > syscheck, bcoz at that time it tries to compare it with the
> > > database it has already made during pre-scan mode.
>
> > > > Regards
> > > > Tanishk Lakhaani
> > > > Sent from BlackBerry® on Airtel
>
> > > > -----Original Message-----
> > > > From: "Nate Woodward" <nate.woodw...@the-connection.com>
>
> > > > Sender: ossec-list@googlegroups.com
> > > > Date: Fri, 4 Mar 2011 10:08:51
> > > > To: ossec-list<ossec-list@googlegroups.com>
> > > > Reply-To: ossec-list@googlegroups.com
> > > > Subject: [ossec-list] Deletion of log data
>
> > > > Hi,
>
> > > > I'm trying to get OSSEC to detect data deletion in log
> > > files. The page
>
> > > athttp://www.ossec.net/doc/manual/monitoring/index.htmlindicatesthat
> > > > log monitoring is done in real time, and ossec_rules.xml has these
> > > > rules:
>
> > > >   <!-- File rotation/reducded rules -->
> > > >   <rule id="591" level="3">
> > > >     <if_sid>500</if_sid>
> > > >     <match>^ossec: File rotated </match>
> > > >     <description>Log file rotated.</description>
> > > >   </rule>
>
> > > >   <rule id="592" level="8">
> > > >     <if_sid>500</if_sid>
> > > >     <match>^ossec: File size reduced</match>
> > > >     <description>Log file size reduced.</description>
> > > >     <group>attacks,</group>
> > > >   </rule>
>
> > > >   <rule id="593" level="9">
> > > >     <if_sid>500</if_sid>
> > > >     <match>^ossec: Event log cleared</match>
> > > >     <description>Microsoft Event log cleared.</description>
> > > >     <group>logs_cleared,</group>
> > > >   </rule>
>
> > > > When I open up a log file in vim, delete a few lines and
> > > save it, rule
> > > > 592 doesn't trigger. Am I doing something wrong? Does real-time log
> > > > monitoring include the rules above, or do those rules only trigger
> > > > when syscheck is run (at which time the log would have grown bigger
> > > > than what it was before, despite my deletions)?
>
> > > > How can I ensure log file integrity?
>
> > > > -Nate

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