SIEM Deployment - Configuring Filtering on SmartConnectors

One of the big obstacles security analysts face when deploying SIEM solutions is that, once you ask system owners to send their "security related" logs to your log collectors, they misunderstand you and save everything.

There are also times that system owners really cannot eliminate junk logs (security wise of course).

Because of the fact that more logs mean more money spent (resources, licensing, storage, etc.) we have to eliminate those logs at same point. In this article, I will detail filtering out logs on SmartConnectors in this article, which is the best place to filter logs because it is the closest to the log source.

The first step of filtering should be deciding which logs you are going to filter. It is never bad to say it again, when collecting logs, do set your scenarios before and know what logs you need to fire your rules. All the rest is garbage, which you can eliminate at some level (source or SmartConnector).

In this example, I have chosen filtering out Microsoft Windows logs and the criterion, I use for it is the deviceEventClassId. You can filter your logs according to any criterion you want.

In order to start, we should run runagentsetup script under your <Connector_Home>\current\bin directory. For the sake of simplicity, I used a windows based SmartConnector for this demo.

In the next menu we choose "Modify Connector" option.

Then "Add, modify, or remove destinations" option should be chosen.

Step 4 is an important step to be well understood. Filtering operation, just like aggregation and other SmartConnector level modifications is made per destination, which means that filtering settings you made are only valid for the Logger or ESM that you choose at this step. If you want to do the filtering for a second destination, you should start over once more. This however and fortunately does not apply for failover destinations.

At step 5, "Modify destination settings" option is chosen.

The next menu is where we actually choose the operation we want to configure.

In the final configuration screen, we enter the parameters according to which we are going to filter the incoming logs. For this example, we are filtering out logs in which deviceEventClassId field contains "Microsoft-Windows-Security-Auditing:4674" or "Microsoft-Windows-Security-Auditing:5447".

If you want to learn more about Microsoft Windows Audit Events, I'd suggest you to visit this website and read this blog article.

Once this step is done, we click next and reach the final configuration screen.

Do not forget to restart your SmartConnector service in order to apply the filtering settings.

SIEM Deployment - Installing ArcSight Systems on Amazon EC2

SIEM systems can be easily considered as “Big Data” systems as the resources they use and the amount of information they process fit into Big Data systems scale. Running SIEM components require serious computing resources not only RAM, CPU and hard disk space but also a high IOPS rate.

For those reasons, if you do not have a chance to have a test environment at work or at home (my home server with i7 CPU (8 thread) and 16GB Ram with 256 GB SSD did not really satisfy me honestly) you should look for another solution. After considering my options about buying a better home server, I found out that cloud solutions such as Amazon’s EC2 offer a way better TCO and ROI comparing to owning a home server.

In this article, I’ll guide you through setting up your own Red Hat Enterprise Linux 6.5 server on which you can either install ArcSight ESM, ArcSight Logger or ArcSight Management Center.

For those who are new to Amazon’s Elastic Cloud 2 (EC2) service, it is basically an Infrastructure as a Service (IaaS) offering where you can build a server with the resources you like and pay as you go. Nothing is charged when you keep your system shut. What’s even better is that, Amazon offers entry level machines for free if you create an account an share your credit card information. As long as you use free tier servers, not even a dime is charged.

Actually these free tier servers come installed with the OS you want and they are the best option to use as SmartConnector servers or as log sources. They are ready to be used only in 10 minutes or less.

First we should log into EC2 console from http://aws.amazon.com/ec2 link. (Registration required)

From the next screen, we choose EC2 option under Compute options.

Once successfully logged into EC2 Management Console, we should launch an instance, either using the “Launch Instance” link on the home page or under Instance option on the left-side menu.

On the next screen, we start configuring our server. The first step is to choose the OS (RHEL 6.5), among the Community AMIs proposed by Amazon.

In Step 2, we should choose an Instance Type among many pre-set instances. This is a very important step as how much we are going to pay and the performance we are going to get largely depends on the instance we choose. For ArcSight Logger, an m4.large instance is sufficient for test purposes as well as for ESM starting with m4.2xlarge or higher is a wise choice.

In Step 3, almost all other details not mentioned in Step 2 are chosen. At this step, I highly recommend choosing a /28 subnet for your environment and enabling “Auto-assign Public IP” option. You may choose to use dedicated hardware resources, if you have some bucks to spend, that would provide you better performance for sure (I never used dedicated hardware on EC2). Finally, you may create more than 1 instances if you plan to install more than one component (ESM, Logger,  ArcMC), that would definitely save you some time.

In Step 4, we set up the storage options. For both ESM and Logger, we need at least 50 GB space for /opt/arcsight directory and at least 5 GB free space for /tmp directory. Because of that we add 2 new volumes having slightly more space than the bare minimum demanded, which we will configure later.

After Step 4 we jump to Step 6 and set access rules for accessing our system. Giving inbound permission for tcp 9000, tcp 8443 and tcp 443 ports (in addition to initial tcp 22 for SSH) in a security group will allow us to apply this security group both to ESM and Logger. You should of course limit access to your system only to your public IP, in case you a have static IP.

After Step 6 our configuration is ready to launch. Accessing Linux devices on EC2 may be a new thing, which I will mention in a short article.

Once we log in to our newly installed server with ec2-user account, we should format and mount partitions following the instructions below (after applying sudo su command of course).

1. First we check our partitions with lsblk command and see some output like below:

   

    $ lsblk

    NAME    MAJ:MIN RM SIZE RO TYPE MOUNTPOINT

    xvda        202:0       0     10G  0   disk

   └─xvda1 202:1       0       6G   0   part   /

    xvdb        202:16    0      52G  0  disk    

    xvdc        202:17    0         8G  0  disk    

2. Then we format xvdb and xvdc drives in ext4 filesystem as below

  

   $ mkfs –t ext4  /dev/xvdb

   $ mkfs –t ext4  /dev/xvdc

3. In the third step, we should mount the partitions to the directories we need as follows:

   

   $ mount  /dev/xvdb  /opt/arcsight

   $ mount  /dev/xvdb  /tmp

4. Basically after this step, we are ready to follow the same steps we do at work or home to install ArcSight systems. However if we miss the following step, the configuration we did will not persist and we may not see the additional partitions mounted after the next reboot. For that reason, we apply following commands:

   $ cp /etc/fstab  /etc/fstab.orig

   $ vi /etc/fstab

Insert the lines below at the bottom of /etc/fstab file and save the file.

/dev/xvdb          /opt/arcsight     ext4       defaults,nofail  0 2

/dev/xvdc          /tmp                  ext4       defaults,nofail  0 2

You can follow AWS documentation link for more detail about this configuration.

Once you finished all these steps, you have a consistent environment for your ArcSight systems.

SIEM Deployment – Configuring Peering Between ArcSight Loggers

When deploying your SIEM Solution Infrastructure with HP ArcSight products, you may consider installing more than one Logger systems for several reasons.

Without going too much into detail for these reasons, let’s name the 2 major ones, first reaching the computation levels on your system (RAM, CPU or 15000 EPS level indicated in HP ArcSight documents) and second providing redundancy, installing an ArcSight Logger appliance for each datacenter for not consuming too much bandwidth to send logs.

Whatever the reason for using several ArcSight Loggers, the problem of lookup in several databases appears.

The solution for this problem is establishing peering between your Logger appliances. Once peering is established, the pattern you are searching for is executed on all peer Loggers and the result is shown on the Logger you initiated the search.

Below you can find the details on peer configuration between two Loggers.

For peering 2 or more loggers should first authenticate each other. For authentication, 2 methods exist:

• Authentication with a logger user credentials
• Authentication with Peer Authorization ID and Code

In this article, we will follow the second method to prevent any problems that may be caused by the user credentials in the first method.

Let's assume, we will initiate the peering on Logger1. To be able to realize it, we should first log in to the Logger2 and generate the Authorization ID and Code for Logger 2.

Once the first step is done, generated values must be entered on Logger1. After successfully saving the configuration Logger Peering is done and logs can be queried through either of the loggers.

UPDATE 29/07/2015: There is something odd about peering config for Loggers. "Add Peer Logger"
option must be configured on both loggers and it is not enough so see one line of peer Logger under Peer Loggers menu. Authorization ID and Code generated on Logger2 for Logger1 must be entered on Logger1 and vice versa. At the end of successfull configuration, you should see 2 identical lines for each Logger you established peering relation under Peer Loggers menu.

SIEM Planning - Reference Architecture for Midsize Deployments

After going through several websites and documents, I sadly discovered, like many of you had before, that HP haven’t yet published any reference architecture or certified design documents for different needs.

I decided to write a series blog articles to create reference architectures for SIEM deployments, basically for HP ArcSight, but the fact that solution components are more or less similar in different vendors, I believe they will be applicable to all SIEM environments.

Gartner defines a small deployment as one with around 300 log sources and 1500 EPS. A midsize deployment is considered to have up to 1000 log sources and 7000 EPS. Finally a large deployment generally covers more than 1000 log sources with approximately 15000 EPS. There can of course be larger deployments with over 15000 EPS but architecture-wise they can be considered as very “large” deployments.

In this article, I will give the details of a midsize deployment, covering components both for a primary datacenter and a disaster recovery center, working in an active-passive setup.

The reference architecture for midsize deployment is for a scenario where the company needs both a long term log storage solution (ArcSight Logger) and Security Event Management and SOC capabilities (ArcSight ESM).

The scheme below shows how different components of the architecture are set up.

• In this setup software SmartConnectors are used to collect the logs. Up to 8 software connectors can be configured on a server and 1 GB of memory should be allocated on the server for each connector instance other than what the server needs for its operation.
• In case appliances are not used, do pay attention to use built-for-purpose hardware servers where resources are not shared because like other big data solutions, these systems are greedy in terms of resources (CPU, Memory, IOPS rate) and do not perform well on virtual environments.
• Sources send logs to one SmartConnector only. SmartConnector level redundancy is only possible only for Syslog connectors and that when connectors are put behind a load balancer. This also provides load sharing and scalability and is a best practice. DB and File connectors do not have such options as they pull the logs from sources.
• When a DB or File collector is down, no log is lost until collector comes back as the logs continue to be written on local resources at the source.
• For log storage and searching, SmartConnectors in each datacenter send their logs to their respective Logger appliance hosted in the same location, providing  important bandwidth savings. Each logger appliance back up the other one using the failover destinations option configured on the SmartConnectors. Thanks to the peering configuration between loggers, logs can be queried through any of the logger appliances without having to connect on each device.
• DC ESM is the primary ESM for both datacenters. DRC ESM is only used in case of DR
• Logs and Alerts are archived daily both on ESM and Logger.
• In DR case, there is no RPO. Configurations for ESM and Logger are planned to be synchronized manually. ESM and Logger are expected to be operational instantly.
• Configuration backups for SmartConnectors and Loggers are collected using Arcsight Management Center (Arc MC).
• SmartConnector statistics and status can be easily followed using Arc MC as well. Realizing SmartConnector updates are also recommended to be done over Arc MC using the GUI.
• SmartConnector level configuration options (aggregation, filter out, batching etc.) are easier to be configured using Arc MC.
• Finally it is strongly recommended to use a Test ESM system to test all filters, rules, active lists and other configuration objects before applying them on production systems as a misconfguration in these settings may crash your ESM and make you lose very valuable data.

SIEM Deployment - ArcSight Logger 6.0 P2 is out

Logger 6.0 P2 is now available for download from HP Software support download page. Note that it is referred to as Logger 6.02 on the download site.

Logger 6.0 P2 includes:

• Important security updates (Honestly I could not find what those updates are in the release notes, even though  I went through the document for multiple times)
• A fix to peer search (LOG-13574).
• Modifications to SOAP APIs:
• SOAP API login events in Audit logs
• SOAP login API now uses the authentication method configured in Logger, which can be an external authentication method, such as Radius. Clients using the SOAP login API must now pass the login credentials for the authentication method configured in Logger (e.g. Radius credentials) instead of the credentials of a local Logger user.

The full release notes can be found HP Protect Website. You may also find the Loggersupport matrix useful.

Some important notes:

• The data migration tool was updated.
• Migration from older Logger versions should be done to Logger 6.0 P1 followed by an upgrade to Logger 6.0 P2.

To resume the migration path, it is for most systems 5.0 GA (L5139) > 5.0 Patch 2 (L5355) > 5.1 GA (L5887) > 5.2 Patch 1 (L6307) > 5.3 GA (L6684) > 5.3 SP1 (L6838) > 5.5 (L7049) > 5.5 Patch 1 (L7067) > 6.0 (L7285) > 6.0 Patch 1 (L7307) > 6.0 Patch 2 (L7334).

The Logger trial version is not updated and remains at Logger 6.0 P1.

About OS version supported there are also no changes and RHEL 6.5 and 6.2 as well as CentOS 5.5 and 6.5 are supported.

SIEM Deployment - Configuring Failover Destinations on HP ArcSight SmartConnectors

SIEM solutions so far seem to be too much focusing on security offerings they propose and they are not offering solid redundancy and disaster solutions.

From architectural perspective, there should be a redundancy option at all layers of the solution architecture. SmartConnectors being the first layer of SIEM interaction with source systems provide a nice redundancy options with “Failover Destination” configuration setting available both for HP ArcSight Logger and HP ArcSight ESM.

For each log processing system, SmartConnector provides a primary destination and a failover destination. As soon as SmartConnector process discovers that logs are not successfully received by the primary destination, they are redirected to the failover destination. Preemption also exists meaning that from the moment primary destination becomes online logs are redirected back to the primary destination.

More detail about the configuration can be seen in the video below.

SIEM Deployment - Installing HP Arcsight SmartConnector on Windows Servers

SIEM system administrators mostly come from Linux world and they prefer using Linux OS for HP ArcSight component installations. I also agree on that decision as the performance and security they provide is superior comparing to Windows Servers.

However there are some situations where you have to use Windows Servers for SmartConnector installations such as when you want to use WinRM application for Windows log collection. Your company may be lacking experienced Linux admins and that could be the second reason to use Windows based SmartConnectors. Last but not the least, as you can see from the installation video, it is much easier to install Windows based SmartConnectors then Linux based ones.

Below, you can find details about the basic installation of an HP ArcSight SmartConnector on a Windows Server for collecting log messages.

REQUIREMENTS / PREREQUISITES

1. A Windows 2008 Server installed.
2. A user with sufficient rights to install the software.
3. A user with added to "Event Log Readers" group to read the logs on the server. (OPTIONAL)
4. Connector binaries downloaded. (Download the correct version for your OS, x86 or x64!!)
5. Connector destinations ( ArcSight Logger and/or ArcSight ESM) installed and working.
6. Create a receiver on the logger to connect the connector.
7. Create a subscription on Event Viewer to get logs.
8. Check the configuration of log receiving folders and increase size.
9. Define the protocol and port on which you will listen the incoming logs.
10. Firewall permissions given for incoming log collection.

INSTALLATION

1. Create installation directory preferably under your second partition E:\SmartConnectors\Microsoft.
2. Run the setup file.
3. Install the connector to run standalone or as a service.
4. Start the connector service from services.msc.
5. Check events on the logger.
6. Set agent.properties parameters.(OPTIONAL)
7. Set agent.wrapper.conf parameters.(OPTIONAL)

SIEM Deployment - ArcSight SmartConnector Build 7.1.4.7475 is out

ArcSight SmartConnector Build 7.1.4.7475 is now available!

Highlights

·           New Amazon Web Services CloudTrail SmartConnector which includes support for Identity and Access Management (IAM), Elastic Compute Cloud (EC2), and CloudTrail Services.

·           Enhanced support for Logger clustering:

o  Beta support for ArcSight Logger SmartMessage Pool destination type which specifies a pool of logger devices. The events are distributed among the loggers in the pool.

·           New RESTful web services CEF connector and standard:

o  Beta support for ArcSight Common Event Format REST connector to collect CEF events from CEF certified cloud vendors. It also extracts assets and vulnerability information from the CEF events.

·           Enhanced WinC international support:

o  Support for non US locale dates parsing.

o  French, Japanese & Chinese support

·           Enhanced IPv6 support:

o  Added a new parser operation to extract IPv4 addresses embedded in IPv6 addresses.

·           Added support for Tenable SecurityCenter’s Assessment Summary Results (ASR) and Asset Reporting Format (ARF) logs in .xml format

New Device, Component, or OS Version Support

SmartConnector	New Device, Component, or OS Version
Blue Coat Proxy SG Syslog	6.5
Juniper Pulse Secure Access Syslog (formerly Juniper Secure Access SSL/VPN Syslog)	8.1
McAfee Network Security Manager DB (Timestamp Based)	8.2
McAfee Network Security Manager DB (ID Based)	8.2
SNMP Unified	RSA Identity Management Service 8.1 RSA Authentication Manager 8.1

SIEM Deployment - Securing HP ArcSight Web Interfaces

2014 and 2015 have been years full of discoveries on cryptographic and algorithmic vulnerabilities starting with Heartbleed following with POODLE and several others. These vulnerabilities pushed many administrators patch their webservers, disable vulnerable protocols (SSLv2, SSLv3 and even TLS1.0) and cipher suites containing weak algorithms (RC4, SHA1, MD5 and others).

ArcSight systems, working over web interfaces, are also subject to these vulnerabilities and possible attacks. Apache web server hosting Logger and Management Center interfaces should be configured to eliminate the cryptographic algorithm and protocol threats.

First of all, to know the status of webserver, we will use the sslscan application with given parameters.

From this output we can see that SSLv2 and SSLv3 protocols are already disabled but protocols such as RC4, DES and Diffie-Hellman are still accepted.

In order to force the webserver to use secure algorithms and protocols we will modify apache configuration file httpd.conf under  <LOGGER_INSTALLATION_DIRECTORY> /local/apache/conf directory, which in my own installation is /opt/arcsight/current/local/apache/conf/.

It is wise to take a backup of the httpd.conf file before making any changes.

# cp httpd.conf httpd.conf.backup

Then we should edit this file with a text editor such as nano or vi.

We should modify the line starting with SSLProtocol and SSLCipherSuite as follows and save the file.

SSLProtocol ALL -SSLv2 -SSLv3

SSLCipherSuite !RC4:!DH:!MD5:!aNULL:!eNULL:!MEDIUM:!LOW:HIGH

After this operation, so that the changes become active we should restart logger services under <LOGGER_INSTALLATION_DIRECTORY>/arcsight/logger/bin directory with ./loggerd restart command.

When we recheck with sslscan, we see that vulnerable options are no longer supported.

SIEM Deployment - Installing HP Arcsight Software Connectors on Linux

In HP ArcSight solution architecture one of the most value adding components is the Smart Connectors. With the several functions they provide, Smart Connectors really help differentiating HP ArcSight’s SIEM solution from other.

So what exactly are ArcSight Smart Connectors? In a 3 layered SIEM Architecture, Arcsight Smart Connectors constitute the second layer between log processing systems ( Arcsight Logger or Arcsight ESM) and source systems generating logs according to defined audit policies.

From technical SIEM perspective, ArcSight Smart Connectors are Java applications which allow receiving or fetching logs from one defined log source, which can be several devices sending their logs in syslog format over the same protocol and port number (e.g. UDP 514) or an application writing its logs to a flat file. ArcSight Smart Connectors come with 256 MB minimum memory size and that memory is adjustable up to 1024 MB by configuration agent.properties file, among other connector properties to be changed according to your specific needs.

One physical server can host up to 8 connector processes, meaning that you can collect logs from 8 different source groups as long as your server support that much capacity.

Below, you can find details about the basic installation of an HP ArcSight Smart Connector on a CentOS Linux server for collecting syslog messages.

REQUIREMENTS / PREREQUISITES

1. A RHEL or CentOS Linux 6.X Server installed.

2. Root or sudo rights for connector user.

3. Connector binaries downloaded. (Download the correct version for your OS, x86 or x64 !!)

4. Connector destinations (Logger and/or ESM) installed and working.

5. Define the protocol and port on which you will listen the incoming logs.

   Choose port numbers over 1024 if you are installing with a non-root user as non-root users are not allowed to listen ports below 1024.

INSTALLATION

1. Create installation directory under /opt path. In this example it is /opt/arcsight/connectors .

2. Create a receiver on the logger to connect the connector.

3. Run the connector binary you previously downloaded. (From /home/arcsight directory in my installation).

# ./ArcSight-7.1.1.7348.0-Connector-Linux64.bin -i console

4. Install the connector to run standalone or as a service.

INSTALLATION_PATH\current\bin\arcsight connectors  à Run Standalone

INSTALLATION_PATH \current\bin\arcsight agentsvc -i -u arcsight -sn syslog_unix à Run with arcsight user as a service with arc_syslog_unix service name

5. Check events on the logger.

6. Set agent.properties parameters (Optional)

7. Set agent.wrapper.conf parameters (Optional)

SIEM Planning - Capacity Planning and Sizing

SIEM projects are well-known to be demanding and greedy when it comes to the resources and your CIOs/CISOs would like to hear about your direct (software licensing, server investment, etc.) and indirect ( archiving storage, support) costs for at least following 3 years other than the benefits the Project will provide.

In this article, I will of course give the basic formulas about sizing. However the most important information to be provided is the real life experience of a live operation concerning the values and comparison to those values to the benchmarks.

First unit, which constitutes the base for all our calculations, is the Event per Second (EPS) value that each source system generates. EPS value greatly depends on 2 factors, audit policy or rules applied on the source system and business of the system. A server with “Object Access” audit rules enabled and Web Server functionality configured of course would not generate the same number of logs with a standard server. Windows family of servers also tends to generate much greater number of logs than Linux and UNIX servers, all with standard default configurations.

EPS estimations can be reached using links 1, 2 and 3.

Having calculated the number of EPS for each source asset group the next step to do is calculating the Event per Day (EPD) value.

EPD = ∑ EPS X 86400

Once EPD value is calculated, we have to decide an average log message size to know how much storage we will need each day. Log sources generate logs starting from 200 bytes range on network and infrastructure devices to 10 kilobytes or more on application and database side.  Syslog standard (RFC 5424) sets the maximum size of the content field of a log message to 2 kilobytes. In light of this information, it is wise and advisable to assume a raw log message size as 500 bytes.

Average raw log message size being set to 500 bytes, the amount of Daily log messages in GB is calculated as follows:

Daily Raw Log Size = EPD * 500 / (1024)³

Log management appliances do some changes on the log messages to make them understandable and meaningful. This operation is called “Normalization” and it increases the log size depending on the solution you use. In my personal experience with HP ArcSight, normalization increased the log size about 90% to 100%. Some other people have seen up to 200% of increase in their experiences.  As a result we obtain the below given formula for daily normalized log size:

Daily Normalized Log Size = Daily Raw Log Size * 2

The calculated value does not really represent the daily storage value for log management systems. Many vendors came up with proprietary compression solutions and claim they compress logs 10 times (10:1) which is quite idealistic. It is however, safe to consider a ratio of 8:1 for calculations. So the formula becomes:

Daily Storage Requirement = Daily Normalized Log Size / 8

The annual storage need would basically be 365 times the Daily Storage Requirement, if you want your calculations to be on the safe side. Nevertheless, EPS numbers seriously fall during weekends and vacations. Watch how much your average EPS numbers decrease in such periods and do your own calculations for your annual needs.

Annual Storage Requirement = Daily Storage Requirement * 365

The last important point is the retention period when you plan your storage investments for future. 2 factors are decisive in the definition of retention period, Compliance Requirements and Security Requirements.

Compliance Requirements only concern Log Management systems, in HP’s case it is Logger and there is not much to decide really, whatever the legislation obliges, you have to configure.

For security needs which are addressed by HP’s ESM system, the decision is yours. I have seen many decision makers trying to keep themselves on the very safe side and take retention periods unnecessarily long.  According to Mandiant, the median number of days attackers were present on a victim network before they were discovered was 205 days in 2014, down from 229 days in 2013 and 243 days in 2012. This brings me to the conclusion that retention period for security alert creation, monitoring, trending and forensics should be at least 1 year and not longer than 3 years. According to the same study of Mandiant, “The longest time an attacker was present before being detected in 2013 was six years and three months.”. Last but not the least, the retention period of course depends on the sector of activity, defense being the longest and the strictest followed by financial institutions.

A rough estimation about Storage IOPS values can be calculated with the following formulas:

Storage IOPS Needed (Direct Attached Storage) = EPS * 1.2

Storage IOPS Needed (SAN) = EPS * 2.5

SIEM Deployment - Windows Local Security Policy (Audit Policy) Configuration

In my previous blog article on collecting logs from Windows Servers, I missed a control point which can be very important while getting results from your SEM installation.

Let me make it more clear for you. While trying to write a correlation rule for an event, in which Windows Server Log Configuration is changed, we first found the event id for such action. After finding the event id, we noticed that although the main audit categories are configured correctly to log both successful and failed attempts, the source system actually did not generate any logs. You will find the reason why below.

The way auditing rules are defined has drastically changed from Windows Server 2003 to Windows Server 2008 and later. In Windows Server 2008, you have the 8 main audit policy categories, each with success and failure options as the scheme below shows.

In addition to main categories, in the same screen at the bottom of the menu, another setting called "Advanced Audit Policy Configuration" exists. Under that option the 8 main categories are detailed under 53 subcategories which provides advanced granularity (not comparing with Linux of course).

The important thing is to know which policy items have precedence over the other, the general policy or the more detailed policy? By default, the main categories have precedence over subcategories, even if you configured both. The way how the default behavior is changed and how it should be configured to avoid complications can be found here. The operation is different for domain computers and non-domain computers.

The best and safe approach to deal with this is to configure the audit policy using the detailed options and force the priority on it over the general policy.

Once it is decided that subcategories are going to be used for auditing, it is important to know what subcategories should be chosen with what actions in order to get the right amount of events. Audit categories concerning object access may generate too many logs to be stored and processed and they can produce important numbers when you have a considerable number of servers to monitor. Once again, the top down approach in design of SEM systems show the correct way, only generate the logs that you are going to need or use for correlation rules or compliance.

After a careful analysis of events and documentation, I ended up creating the policy below for my installations. I believe that this policy covers most of the needs but if you consider using it you'd better spend some time to adjust it according to your own needs.

Finally, the policy slightly differs for Active Directory Domain Controllers and the other servers as DS Access category only concerns Domain Controllers. For a non-DC server all the subcategories under DS Access category should be set to "No auditing".

SYSTEM AUDIT POLICY SETTINGS
Category/Subcategory	Suggested Settings
System
Security System Extension	Success and Failure
System Integrity	Success and Failure
IPsec Driver	No Auditing
Other System Events	Failure
Security State Change	Success and Failure
Logon/Logoff
Logon	Success and Failure
Logoff	Success and Failure
Account Lockout	Success and Failure
IPsec Main Mode	No Auditing
IPsec Quick Mode	No Auditing
IPsec Extended Mode	No Auditing
Special Logon	Success and Failure
Other Logon/Logoff Events	Success and Failure
Network Policy Server	Success and Failure
Object Access
File System	Success and Failure
Registry	Success and Failure
Kernel Object	Success and Failure
SAM	No Auditing
Certification Services	Success and Failure
Application Generated	Success and Failure
Handle Manipulation	No Auditing
File Share	Success and Failure
Filtering Platform Packet Drop	No Auditing
Filtering Platform Connection	No Auditing
Other Object Access Events	No Auditing
Detailed File Share	No Auditing
Privilege Use
Sensitive Privilege Use	No Auditing
Non Sensitive Privilege Use	No Auditing
Other Privilege Use Events	No Auditing
Detailed Tracking
Process Termination	Success and Failure
DPAPI Activity	No Auditing
RPC Events	Success and Failure
Process Creation	Success and Failure
Policy Change
Audit Policy Change	Success and Failure
Authentication Policy Change	Success and Failure
Authorization Policy Change	Success and Failure
MPSSVC Rule-Level Policy Change	No Auditing
Filtering Platform Policy Change	No Auditing
Other Policy Change Events	Failure
Account Management
User Account Management	Success and Failure
Computer Account Management	Success and Failure
Security Group Management	Success and Failure
Distribution Group Management	Success and Failure
Application Group Management	Success and Failure
Other Account Management Events	Success and Failure
DS Access
Directory Service Changes	Success and Failure
Directory Service Replication	No Auditing
Detailed Directory Service Replication	No Auditing
Directory Service Access	Success and Failure
Account Logon
Kerberos Service Ticket Operations	Success and Failure
Other Account Logon Events	Success and Failure
Kerberos Authentication Service	Success and Failure
Credential Validation	Success and Failure