Difference between revisions of "Intrusion Prevention3"

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<span style="display:none" class="helpSource intrusion_prevention">Intrusion_Prevention</span>
<span style="display:none" class="helpSource intrusion_prevention_status">Intrusion_Prevention#Status</span>
<span style="display:none" class="helpSource intrusion_prevention_rules">Intrusion_Prevention#Rules</span>
<span style="display:none" class="helpSource intrusion_prevention_variables">Intrusion_Prevention#Variables</span>
<span style="display:none" class="helpSource intrusion_prevention_event_log">Intrusion_Prevention#Event_Log</span>
{| width='100%'
| align="center" | [[Image:IntrusionPrevention.png|128px]] &nbsp; &nbsp; '''Intrusion Prevention'''
| align="center" |
| Other Links:
|[http://www.untangle.com/store/intrusion-prevention.html Intrusion Prevention Description Page]
|[http://demo.untangle.com/admin/index.do#service/intrusion-prevention Intrusion Prevention Demo]
|[http://forums.untangle.com/intrusion-prevention/ Intrusion Prevention Forums]
|[[Intrusion Prevention Reports]]
|[[Intrusion Prevention FAQs]]
== About Intrusion Prevention ==
Intrusion Prevention is an [http://en.wikipedia.org/wiki/Intrusion_detection_systems Intrusion Detection system] that detects malicious activity on your network.
To detect malicious activity, Intrusion Prevention uses signature detection, a method that draws upon a database of known attack patterns.
If Intrusion Prevention detects malicious activity, the [http://en.wikipedia.org/wiki/Session_%28computer_science%29 session] for that activity can be logged or blocked.
''Note:'' Intrusion Prevention installs but is off by default.
''Note:'' Intrusion Prevention requires at least 2 gigabytes of RAM.
=== Signatures & Actions ===
A signature matches behavior patterns such as plain text in a connection or the number of times a particular host attempts to open TCP connections to another host.
When the conditions for a signature are met, the incident is either logged to the event log without distruption to the session or blocked which both logs the incident but breaks the connection causing that session to "stop".
The default signature database is automatically populated and updated on a regular basis, usually every 2-3 days.
You can add custom signatures if you wish but it is not neccessary.
While it is tempting to block all signatures, there is a high potential for false positives which could cause legitmate traffic to stop working.
It is therefore recommmnted that signatures are logged, the event log reviewed, and if the incident is deemed problematic, change the signature action to block.
It may be similarly temping to log all signatures.
While logging won't stop traffic it will consume system processing resources (CPU and memory) and potentially fill your event log with false positives.
A signature can also be disabled.  This means is it not loaded into the engine at all.
Signature actions are set by rules.  In the context of signatures, actions are recommmended only.
=== Rules ===
Rules match characteristics of signatures and if matched, set signature action as follows:
* Recommended
* Enable Log
* Enable Block if Recommended is Log
* Emable Block
* Disable
* Signature Identifier
* Group Identifier
* Category
* Classtype
* Message
* Protocol
* Source Address
* Source Port
* Destination Address
* Destination Port
* Any part of signature
* Custom signature
* Recommended Action
* System Memory
=== Variables ===
Variables define common attributes like the home network and ports.  Under most circumstances these should be left alone. 
For HOME_NET and EXTERNAL_NET, the default values ensures these are automatically calculated.
=== Memory ===
Intrusion Prevention can be memory intensive.  How much is used is a combination of the number of signatures enabled for Log or Block and the amount of traffic that goes through your system.
== Settings ==
=== Status ===
The Status tab shows the following information:
* Memory Usage.  The amount of system memory the IPS engine is using compared to your installed system memory.
* Metrics.  The number of blocked, logged, and scanned sessions.
* Overview.  Signatures and Signature Updates.
** Signatures.  Total number of signatures available and the number set for Log, Block, Disabled.
** Updates.  The last time signatures were updated and the last time a check was performed.  Updates do not neccessarily occur on each check.
=== Rules ===
Simply uncheck '''Block''' (and '''Log''' if you wish) and the the traffic will no longer be blocked.
*Edit: Edit the rule. This is not recommended and should only be attempted by advanced users with a strong understanding of Snort rules. Invalid or poorly written rules will negatively impact network performance.
=== Signatures ===
Intrusion Prevention provides a list of [[#Learning More About Signature ID Rules|signatures]] that you can have Untangle '''Log''' or '''Block''' when traffic matches them. The rules are grouped by classtype and can be searched using the search field at the bottom of the page.
In most cases, you do not need to change the recommended settings. You should only need to disable a signature if that rule blocks traffic from a unique software application that you must use. CREATE RULES.
The signatures are automatically updated using the latest Snort signatures.
*SID: The signature's identifier.
*Classtype: Snort classtype (grouping) of the signature.
*Category: Snort category (grouping) for the signature.
*Msg: Name of the signature.
*Reference: Links to reference information on the attack the signature will detect (if available).
*Log/Block: Enable these to log or block traffic matching the signature.
*Edit: Modify a a custom signature from the system.
*Copy: Copy a signature.  Copied signatures become part of the custom set.
*Delete: Delete a custom signature from the system.
Using the Add button, you can also add your own custom signatures to the system. This should only be attempted by advanced users with a strong knowledge of Suricata signature creation. Adding invalid or poorly written rules will negatively impact network performance.
=== Variables ===
This tab provides administrators access to Suricata variables. These variables are used in rules to specify criteria for the source and destination of a packet.
Snorts most important variable is $HOME_NET. $HOME_NET defines the network or networks you are trying to protect - it is computer automatically based on your network configuration - it includes all local networks (including aliases).
Using the Add button, custom variables can be added. Adding variables may be used by users adding their own rules.This should only be attempted by advanced users with a strong knowledge of Snort signature creation.
== Updates ==
Signatures are automatically updated every night.  Any rule modifications the administrator has made will remain.  New signatures are added with recommended actions.
== Reports ==
{{:Intrusion Prevention Reports}}
== Related Topics ==
[http://en.wikipedia.org/wiki/Intrusion_prevention_system Intrusion Prevention Systems]
[http://manual.snort.org/node36.html Snort - Writing Good Snort Rules]
[http://manual.snort.org/node27.html Snort - Writing Snort Rules]
== Intrusion Prevention FAQs ==
{{:Intrusion Prevention FAQs}}

Latest revision as of 20:57, 13 November 2018