Tutorial / Cram Notes
Syslog is a standard for message logging across different devices and systems. It allows for the separation of the software that generates messages, the system that stores them, and the software that reports and analyzes them.
Designing Syslog Event Collection
- Identify the source devices: Determine which network devices, such as routers, switches, and firewalls, will send Syslog messages.
- Define the Syslog version: Ensure consistency by specifying whether the devices should use Syslog or Rsyslog and which version to support.
- Choose the appropriate facility level: Syslog messages are classified by facility levels to indicate the type of software that generated the message. These range from kern for kernel messages to local0 through local7 for custom use.
- Specify the severity levels: These levels range from emergency (emerg) to debug (debug) and help determine the importance of the messages.
- Designate a collector: Decide on a centralized Syslog server or SIEM that will gather and store the logs.
Configuring Syslog Collection
- Configuration on Source Devices:
- Set the IP address of the Syslog server.
- Define the ports to be used (default is UDP 514).
- Specify the types of messages to be sent based on their facility and severity levels.
- Configuration on the Syslog Server:
- Ensure the Syslog service is running.
- Configure the service to listen on the appropriate port.
- Define rules for log rotation and archival.
Common Event Format (CEF) Event Collection
CEF is a text-based format designed to support multiple device types by offering a standardized event format.
Designing CEF Event Collection
- Identify the data sources: Ascertain which devices or applications can output logs in CEF format.
- Understand the CEF structure: Familiarize yourself with CEF headers and extensions, which include a predefined set of fields such as timestamp, event class ID, name, severity, and device-specific extensions.
- Plan the parsing strategy: Decide if any preprocessing is required to parse fields correctly in your SIEM.
Configuring CEF Collection
- Configuration on Data Sources:
- Enable CEF logging on the devices or applications.
- Define transport mechanisms (e.g., TCP or UDP) and the destination.
- Configuration on the SIEM:
- Add data connectors specific to the CEF source.
- Input the necessary details to establish a connection, such as IP, port, and protocol.
- Verify that the SIEM parses CEF logs properly by checking if fields are correctly mapped.
Practical Implementation Example
Imagine a scenario where you have a set of Palo Alto firewalls that you want to send Syslog messages to Azure Sentinel.
- On the firewalls:
- Define the Syslog server as your Azure Sentinel workspace IP.
- Set up the appropriate port, for example, UDP 514.
- Filter logs by severity, ensuring you’re forwarding only those that are relevant to your monitoring goals.
- In Azure Sentinel:
- Navigate to Data connectors and search for Palo Alto Networks.
- Follow the instructions for setting up the connector, which typically involves deploying an agent to consume Syslog messages.
For CEF collection, suppose you have an ArcSight SmartConnector that reformats security event logs into CEF.
- On your security devices:
- Configure each to send logs to the SmartConnector.
- On the SmartConnector:
- Set up the connector to read incoming logs, reformat them into CEF, and send them to a destination IP (your Azure Sentinel workspace IP).
Comparison
| Key Aspects | Syslog | CEF |
|---|---|---|
| Format | Less structured, variable based on device | Highly structured with defined schemas |
| Parsing | May require custom parsing rules | Typically easier with pre-defined fields |
| Transport | Commonly over UDP; can be less secure | Supports TCP, which can offer more reliable delivery |
| Integration | Wide support in various devices | Requires devices to support CEF directly or via a connector |
Conclusion
In your role as a security operations analyst, effectively configuring Syslog and CEF event collection is paramount to obtaining visibility across your environment. Whether dealing with network devices, servers, or specialized security equipment, mastering the collection of these log formats will expand your threat hunting and incident response capabilities. As you prepare for the SC-200 certification, ensure you gain practical experience in setting up these collection methods in a lab or real-world environment to solidify your understanding.
Practice Test with Explanation
True or False: Syslog is only used for collecting security logs from Windows devices.
- False
Syslog is a standard for message logging that can be used to collect security and other system logs from a variety of devices, including both Windows and non-Windows systems, such as Unix/Linux, routers, and switches.
True or False: The Common Event Format (CEF) is a text-based log format that is not compatible with Syslog.
- False
The Common Event Format (CEF) is actually designed to be compatible with Syslog. It is a text-based log format that includes structured data, making it easy to integrate with Syslog servers and security information and event management (SIEM) systems.
Which port is commonly used by Syslog for log transmission over the network?
- A) TCP 443
- B) UDP 514
- C) TCP 22
- D) UDP 69
B) UDP 514
Syslog traditionally uses UDP port 514 for log transmission, although it can be configured to use TCP as well.
Multiple Choice: Which of the following are common Syslog severity levels? (Select all that apply)
- A) Informational
- B) Verbose
- C) Debug
- D) Critical
A) Informational and C) Debug and D) Critical
Informational, Debug, and Critical are common Syslog severity levels that indicate the importance or urgency of the logs. “Verbose” is not a standard Syslog severity level.
True or False: CEF event logging can only be configured on network devices.
- False
CEF event logging is not just limited to network devices; it can also be configured on security appliances, applications, and various other systems that support the CEF standard.
True or False: Windows Event Forwarding (WEF) uses the Syslog protocol to transfer event logs.
- False
Windows Event Forwarding (WEF) does not use the Syslog protocol. It uses Windows protocols and services, such as the WS-Management protocol, to transfer event logs within a Windows environment.
How are logs typically secured during transmission in a Syslog setup?
- A) By default, logs are encrypted with SSL/TLS.
- B) Logs are compressed to prevent unauthorized access.
- C) Logs are sent in plaintext unless specifically configured for secure transfer.
- D) Logs are encoded with Base64 before transmission.
C) Logs are sent in plaintext unless specifically configured for secure transfer.
By default, Syslog transmits logs in plaintext. To secure logs during transmission, additional configurations like implementing Syslog over TLS/SSL must be applied.
In the context of CEF event collection, what does “extension” refer to?
- A) The file extension of the log file.
- B) Additional headers that can be added to the Syslog message.
- C) The optional part of the CEF message that contains additional event metadata.
- D) A software module that enhances the capabilities of the event collector.
C) The optional part of the CEF message that contains additional event metadata.
In CEF event collection, “extension” refers to the optional part of the message that can include additional metadata about the event, providing more context to the collected logs.
True or False: CEF is a proprietary event format that can only be used with certain SIEM products.
- False
CEF is not a proprietary event format; it is an open log management standard and can be used with various SIEM products that support it.
Which of the following would you commonly use to configure and administer event logging on a Unix/Linux system?
- A) Event Viewer
- B) Syslog or rsyslog
- C) Task Scheduler
- D) Performance Monitor
B) Syslog or rsyslog
Syslog or rsyslog is the standard logging utility for Unix/Linux systems, used for handling and configuring system logging.
True or False: It is possible to integrate CEF log data with Microsoft Sentinel for security analysis and threat detection.
- True
Microsoft Sentinel supports the integration of CEF log data, enabling security analysis and threat detection. Microsoft Sentinel can parse and interpret CEF-formatted data for security insights.
Which syslog facility code is typically used for logging security/authorization messages?
- A) auth
- B) daemon
- C) user
- D) local0 through local7
A) auth
The “auth” facility code is commonly used in Syslog for security/authorization messages, though “authpriv” is used for messages with private authentication. “daemon” is for system daemons, “user” for user-level messages, and “local0” through “local7” are reserved for locally defined uses.
Great post on configuring Syslog and CEF events collection! Very helpful for my SC-200 exam prep.
I appreciate the detailed explanation on setting up syslog servers.
I’ve always been confused about the differences between Syslog and CEF. This blog post cleared things up for me.
Does anyone know if we need to install any specific roles or features on Windows Server to collect Syslog?
How can we forward CEF logs to Azure Sentinel?
The screenshots for the configurations were really helpful. Thanks!
One thing I struggle with is filtering and parsing the logs correctly. Any tips?
Appreciate the blog post. Saved me a lot of time!