Hello Steve,

Thanks so much for your help! I've included your suggested filter in audit.rules as shown below:

# cat audit.rules1

      1 # This file contains the auditctl rules that are loaded
      2 # whenever the audit daemon is started via the initscripts.
      3 # The rules are simply the parameters that would be passed
      4 # to auditctl.
      5 # First rule - delete all
      6 -D
      7 # Increase the buffers to survive stress events.
      8 # Make this bigger for busy systems
      9 -b 320
     10 ### Feel free to add below this line. See auditctl man page
     11 -a exit,always -F arch=b64 -F euid=0 -S execve -k rootact
     12 -a exit,always -F arch=b32 -F euid=0 -S execve -k rootact
     13 -a exit,always -F arch=b64 -F euid>=500 -S execve -k useract
     14 -a exit,always -F arch=b32 -F euid>=500 -S execve -k useract
     15 -a exit,always -F arch=b64 -F euid=0 -F auid!=unset -S execve -k rootact
     16 -a exit,always -F arch=b32 -F euid=0 -F auid!=unset -S execve -k rootact

After restarting the auditd service following error received:

# service auditd restart
Stopping auditd:                                           [  OK  ]
Starting auditd:                                           [  OK  ]
Unknown user: unset
-F unknown field: auid
There was an error in line 15 of /etc/audit/audit.rules

# auditctl -l
LIST_RULES: exit,always arch=3221225534 (0xc000003e) euid=0 key=rootact syscall=execve
LIST_RULES: exit,always arch=1073741827 (0x40000003) euid=0 key=rootact syscall=execve
LIST_RULES: exit,always arch=3221225534 (0xc000003e) euid>=500 (0x1f4) key=useract syscall=execve
LIST_RULES: exit,always arch=1073741827 (0x40000003) euid>=500 (0x1f4) key=useract syscall=execve

# auditctl -a exit,always -F arch=b64 -F euid=0 -F auid!=unset -S execve -k rootact
Unknown user: unset
-F unknown field: auid

You advice would be much appreciated.

Many thanks,

Kind regards,
Moshe

Moshe Rechtman

Technical Support Engineer

Red Hat Israel

34 Jerusalem rd. Ra'anana, 43501

mrechtma@redhat.com   T: +972-9-7692289 
M: +972-54-4971516   F: +972-9-7692223    



On Fri, Feb 21, 2020 at 2:27 AM Steve Grubb <sgrubb@redhat.com> wrote:
Hello,

On Thursday, February 20, 2020 7:04:37 PM EST Moshe Rechtman wrote:
> Those particular logs generated by a third party monitoring application
> named Microfocus, which keeps on running "ps -auxwwww" command and filling
> up quickly the audit log.

It looks like this is a daemon since auid is -1. So, I'd suggest that the
rule be something like:

-a exit,always -F arch=b64 -F euid=0 -F auid!=unset -S execve -k rootact

This will not filter just that one item, it will filter all execution by all
daemons.

-Steve

> > On Thursday, February 20, 2020 6:36:46 PM EST Moshe Rechtman wrote:
> > > $ cat audit.rules
> > >
> > > # This file contains the auditctl rules that are loaded
> > > # whenever the audit daemon is started via the initscripts.
> > > # The rules are simply the parameters that would be passed
> > > # to auditctl.
> > >
> > > # First rule - delete all
> > > -D
> > >
> > > # Increase the buffers to survive stress events.
> > > # Make this bigger for busy systems
> > > -b 320
> > >
> > > # Feel free to add below this line. See auditctl man page
> > >
> > > -a exit,always -F arch=b64 -F euid=0 -S execve -k rootact
> > > -a exit,always -F arch=b32 -F euid=0 -S execve -k rootact
> > > -a exit,always -F arch=b64 -F euid>=500 -S execve -k useract
> > > -a exit,always -F arch=b32 -F euid>=500 -S execve -k useract
> > >
> > >
> > > Audit start working as expected. Now customer is asking to
> > > exclude/ignore the following from audit logs:
> > >
> > > type=SYSCALL msg=audit(1581664357.597:257516): arch=c000003e
> > > syscall=59 success=yes exit=0 a0=3869161ea3 a1=7ffd15530c20
> > > a2=7ffd15534348 a3=3869617240 items=2 ppid=3350 pid=59266
> > > auid=4294967295 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0
> > > fsgid=0 tty=(none) ses=4294967295 comm="sh" exe="/bin/bash"
> > > key="rootact"
> > > type=EXECVE msg=audit(1581664357.597:257516): argc=3 a0="sh" a1="-c"
> > > a2=2F62696E2F70732061757877777777
> > > type=CWD msg=audit(1581664357.597:257516):
> > > cwd="/opt/microfocus/Discovery/bin" type=PATH
> > > msg=audit(1581664357.597:257516): item=0 name="/bin/sh" inode=398
> > > dev=fd:01 mode=0100755 ouid=0 ogid=0 rdev=00:00
> > > nametype=NORMAL
> > > type=PATH msg=audit(1581664357.597:257516): item=1 name=(null)
> > > inode=4481 dev=fd:01 mode=0100755 ouid=0 ogid=0 rdev=00:00
> > > nametype=NORMAL
> > >
> > > ype=SYSCALL msg=audit(1581664357.601:257517): arch=c000003e syscall=59
> > > success=yes exit=0 a0=155c2f0 a1=155b8d0 a2=155b460 a3=18 items=2
> > > ppid=3350 pid=59266 auid=4294967295 uid=0 gid=0 euid=0 suid=0 fsuid=0
> > > egid=0 sgid=0 fsgid=0 tty=(none) ses=4294967295 comm="ps"
> > > exe="/bin/ps" key="rootact"
> > > type=EXECVE msg=audit(1581664357.601:257517): argc=2 a0="/bin/ps"
> > > a1="auxwwww" type=CWD msg=audit(1581664357.601:257517):
> > > cwd="/opt/microfocus/Discovery/bin" type=PATH
> > > msg=audit(1581664357.601:257517): item=0 name="/bin/ps" inode=1451
> > > dev=fd:01 mode=0100755 ouid=0 ogid=0 rdev=00:00
> > > nametype=NORMAL
> > > type=PATH msg=audit(1581664357.601:257517): item=1 name=(null)
> > > inode=4481 dev=fd:01 mode=0100755 ouid=0 ogid=0 rdev=00:00
> > > nametype=NORMAL
> > >
> > > What would be the best way to exclude such audit?
> > > Your help would be much appreciated.
> >
> > What's objectionable about these events? The fact that its got a key says
> > they think they wanted it.
> >
> > -Steve