Rule to collect events for deleting a user from a group
A successful usermod command has been detected in the system log files.
A user was deleted from a group on the system. This monitor allows system administrators to track account/group creation and deletion.
The description of the alert and/or the output data item contains information on the event encountered. If the activity appears suspicious, please check the associated event details and any other events that happened around the time of this event.
Target | Microsoft.ACS.Linux.RHEL.4.ACSEndPoint |
Category | EventCollection |
Enabled | True |
Alert Generate | False |
Remotable | True |
ID | Module Type | TypeId | RunAs |
---|---|---|---|
EventDS | DataSource | Microsoft.Unix.SCXLog.Privileged.Datasource | Default |
WA | WriteAction | Microsoft.ACS.Unix.SecureEventLogWriter | Default |
<Rule ID="Microsoft.ACS.Linux.RHEL.4.Deleting.User.From.Group" Enabled="true" Target="Microsoft.ACS.Linux.RHEL.4.ACSEndPoint" Remotable="true">
<Category>EventCollection</Category>
<DataSources>
<DataSource ID="EventDS" TypeID="Unix!Microsoft.Unix.SCXLog.Privileged.Datasource">
<Host>$Target/Host/Property[Type="Unix!Microsoft.Unix.Computer"]/NetworkName$</Host>
<LogFile>/var/log/secure</LogFile>
<!-- [TYPE] Redhat4 UserDeleteFromGroup True -->
<!-- [INPUT] Oct 15 18:18:48 scxcrd-rhe40-01 usermod[8382]: delete `tempuser' from group `tempgroup' -->
<!-- [EXPECTED] date="Oct 15 18:18:48"; hostname="scxcrd-rhe40-01"; process="usermod"; processId="8382"; clientUser="tempuser"; groupName="tempgroup" -->
<RegExpFilter>\s+usermod\[[[:digit:]]+\]: delete `\S+' from group `\S+'</RegExpFilter>
</DataSource>
</DataSources>
<WriteActions>
<WriteAction ID="WA" TypeID="ACS.Unix!Microsoft.ACS.Unix.SecureEventLogWriter">
<RegExp>(?'date'\S+\s+\d+\s+\d+:\d+:\d+)\s+(?:\S+:)?(?'hostname'\S+)\s+(?'process'usermod)\[(?'processId'\d+)\]: delete `(?'clientUser'\S+)' from group `(?'groupName'\S+)'</RegExp>
<EventType>1</EventType>
<EventId>27005</EventId>
<BackrefOverrides>sessionName="User removed from group"</BackrefOverrides>
</WriteAction>
</WriteActions>
</Rule>