Re: Question about excluding rules

[Steve Grubb <sgrubb@redhat.com>]

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