OSSEC HIDS v0.9
Copyright (c) 2003-2006 Daniel B. Cid <dcid@ossec.net>



--- Rules Classification ---


-- Classification --

The rules are classified in multiple levels. From the lowest (00) to the maximum
level 16. Some levels are not used right now. Other levels can be added between
them or after them. 

**The rules will be read from the highest to the lowest level. **

00 - Ignored - No action taken. Used to avoid false positives. These rules
     are scanned before all the others. They include events with no
     security relevance.
01 - None -
02 - System low priority notification - System notification or 
     status messages. They have no security relevance.
03 - Successful/Authorized events - They include successful login attempts,
     firewall allow events, etc.
04 - System low priority error - Errors related to bad configurations or
     unused devices/applications. They have no security relevance and
     are usually caused by default installations or software testing.
05 - User generated error - They include missed passwords, denied
     actions, etc. By itself they have no security relevance.
06 - Low relevance attack - They indicate a worm or a virus that have
     no affect to the system (like code red for apache servers, etc).      
     They also include frequently IDS events and frequently errors.
07 - "Bad word" matching. They include words like "bad", "error", etc.
     These events are most of the time unclassified and may have
     some security relevance.
08 - First time seen - Include first time seen events. First time
     an IDS event is fired or the first time an user logged in.
     If you just started using OSSEC HIDS these messages will
     probably be frequently. After a while they should go away.
     It also includes security relevant actions (like the starting
     of a sniffer or something like that).
09 - Error from invalid source - Include attempts to login as
     an unknown user or from an invalid source. May have security 
     relevance (specially if repeated). They also include errors
     regarding the "admin" (root) account.
10 - Multiple user generated errors - They include multiple bad
     passwords, multiple failed logins, etc. They may indicate an
     attack or may just be that a user just forgot his credencials.
11 - Integrity checking warning - They include messages regarding
     the modification of binaries or the presence of rootkits (by
     rootcheck). If you just modified your system configuration
     you should be fine regarding the "syscheck" messages. They
     may indicate a sucessful attack. Also included IDS events
     that will be ignored (high number of repetitions).
12 - High importancy event - They include error or warning messages
     from the system, kernel, etc. They may indicate an attack against 
     a specific application.
13 - Unusual error (high importance) -  Most of the times it matches a
     common attack pattern.
14 - High importance security event. Most of the times done with 
     correlation and it indicates an attack.
15 - Severe attack - No chances of false positives. Immediate
     attention is necessary.


== Rules Group ==

-We can specify groups for specific rules. It's used for active
response reasons and for correlation.
- We currently use the following groups:

- invalid_login
- authentication_success
- authentication_failed
- connection_attempt
- attacks
- adduser
- sshd
- ids
- firewall
- squid
- apache
- syslog


     
== Rules Config ==

http://www.ossec.net/en/manual.html#rules

