Log Files in Cyber Security – Definition, Types, & Its Importance Explained

Written By Sambita Panigrahy  
Anuraag Singh
Approved By Anuraag Singh 
Published On January 8th, 2024
Reading Time 8 Minutes Reading

Regardless of the industry type, enterprises these days can no longer afford to overlook their log files because of the rising cost of security incidents. Logs have been playing an important part in the cybersecurity environment for a while now. So, let’s have a look at what a log file is, its importance, its different types, and more information related to it.

First, let’s start with the definition.

What are Log Files?

Log files are computer-generated files that contain a list of records and events. It stores events, processes, messages, and other data from applications, operating systems, or devices. They play a significant role in monitoring IT settings by providing information based on the user’s actions. You can check to see whether everything is operating as it should and also see if the system or network has been compromised.

These files contain information about program events which give an overview of detected threats. 

Different Types of Log Files

Nearly every network component produces a unique type of log file in the database that each component logs individually. Consequently, there are numerous different types of logs. Such as:

  • Event Logs: It is a high-level log that keeps track of network usage information like failed login attempts, incorrect password attempts, and application events.

Note: Log retention is a critical component of any cybersecurity strategy. For more information on the log retention policy, contact our expert team now!

  • Server Logs: It is a text file that records activities on a specific server over a period of time.
  • System logs: Frequently referred to as Syslog, is a record of system events. Unexpected shutdowns, system modifications, errors, and other critical operations are all covered. Syslogs are generated by Windows, Linux running in the log directory, and macOS.
  • Authorization and Access Logs: The names of people or bots who have accessed particular programs or files are listed in authorization and access logs.
  • Change Logs: It is a list of every change that has ever been made to a program or file.
  • Availability Logs:  It keeps track of System Uptime, Performance, and Availability.
  • Resource Logs: These record connectivity issues and capacity limitations.
  • Risk Logs: These logs are records of system, file, or application traffic that correspond to the security profile of a firewall.

Some other log files include:

  1. Internet server logs: Web programs like Apache and NGINX produce web server log files that provide an unfiltered view of website traffic. In weblogs, you can find out “who” visited your website (IP address) and “which” pages were looked at (URLs). Additionally, you can spot spider traps, hacker-dropped spam, broken external links, bad server answers, and exploit attempts.
  2. Netflow logs: According to their network activities, switches, routers, firewalls, VPN concentrators, and other connected devices provide various records.  Unauthorized attempts to launch programs or access restricted data can be found, failed user login attempts can be recorded, and much more in a network log.  
  3. Application logs: These logs are stored in software applications. They provide a lot of information about an application’s performance, including disc space warnings, completed operations, problems that prevent the application from beginning, successful login audits, and audits of login failures. You can use them for troubleshooting, diagnostics, and auditing.
  4. Container Logs: You can usually capture the output or error that applications running in containers often log to stderr or stdout. For instance, you can set up a logging driver to transport logged stdout or stderr messages to a distant destination in order to capture Docker container logs. Container logs may be entirely JSON files or entirely plain text files.

Anyway, the question is why log files are important.

Know The Importance of Log Files

Log files are crucial because they preserve essential data that can be utilized to reconstruct past events, identify security holes, or troubleshoot. Here are the top five reasons to keep an eye on your logs.

  • Greater Efficiency: You can reduce downtime, reduce the chance of data loss, and access important information like the need for updates or potential performance improvement areas by keeping an eye on log files. Additionally, some logs (such as database query logs) offer latency data that can be utilized to identify time-wasting activities. 
  • More rapid troubleshooting: Log information can be used to debug errors and figure out what went wrong. For instance, you can look through the log files to determine why a service crashes if it goes down. Did it face an unhandled exception, run out of memory, or was there another reason? Businesses use log monitoring to deliver transparency and insight into the computer environment, increase network observability, prevent or correct operating system issues, and more.
  • Security audits and penetration testing: Since log files provide a complete history of system activity, including access attempts, command-line input, modifications to sensitive information, and more, security experts rely on them as a reliable source of audit data. In order to figure out how someone got access to the network if it has been compromised, you can use log files to reverse engineer and go back into the kill chain. 
  • Recognize user behavior: Examining log files and user behavior can help businesses better understand how users engage with their products (applications). This aids developers in better-comprehending consumer requirements and customizing the program to suit them.
  • Analysis of Data: A secure server that acts as a centralized logging point frequently receives the data from the log files. Before the system administrator can handle it, typically. However, log aggregation, or collecting all logs in one datastore, is frequently insufficient. For instance, you might wish to create visualizations of the world with the countries that your website is intended for. Log management software can help with that since it makes it simple to gather, sort, and analyze log files.

Who Mostly Uses Log Files?

Log files are used differently by different professionals. Here are a few illustrations of various professional groups and how they use log files.

  • ITOps (Information Technology Operations) uses log files to assess the IT infrastructure health of a business, assisting them in managing workload, minimizing downtime, maintaining operations, and lowering operational and financial risk.
  • Log files are used by DevOps engineers to monitor CI/CD, maintain smooth application operation, find problems before they cause downtime, and enhance performance.
  • Log files are used by DevSecOps to establish shared ownership of program development and security, hence saving time and money and lowering risks by identifying potential flaws before release.
  • Ethical hackers and security researchers look for attack “who,” “when,” and “where” information in log files, which they use to look for irregularities in network flows that are prohibited and authorized.
  • Log files are used by IT analysts for reporting on capital expenditures (CapEx) and operating expenditures (OpEx) as well as compliance control.


Q. What are log files in Cybersecurity?
Log files are documents that include records of actions or occurrences on a network, computer system, or application. Log files are essential for monitoring and evaluating security-related events in cybersecurity.

Q. Why are cybersecurity log files important?

Log files offer an in-depth chronicle of system operations, assisting cybersecurity experts in identifying, examining, and addressing security events. They are necessary for troubleshooting, compliance, and forensic analysis.

Q. What kinds of events do cybersecurity logs?

Login attempts, system and application problems, configuration changes, network traffic, and security-related events like firewall and intrusion detection system warnings are among the often recorded events.

Q. Normally, where are log files kept?

On a system, log files are often kept in designated directories. /var/log on Unix/Linux systems and C:\Windows\System32\winevt\Logs on Windows are common places.

Q. What distinguishes system logs from security logs?

The main purpose of security logs is to document security-related activities including login attempts and modifications to access controls. On the other hand, general system events, such as warnings, errors, and informative messages, are recorded in system logs.

Q. For what reason should log data be kept on file for a long time?

The length of a log’s retention depends on its type, organizational policy, and legal requirements. Logs are frequently kept for a set amount of time (such as 90 days) in order to aid with incident response and compliance.

Q. What typical difficulties arise when handling log files?

The sheer amount of log data, the requirement for real-time analysis, maintaining data integrity, and striking a balance between controlling storage costs and preserving adequate information for investigations are some of the difficulties.

Q. What benefits might log file management receive from Security Information and Event Management (SIEM) systems?

SIEM systems offer a centralized platform for tracking and reacting to security events by aggregating, correlating, and analyzing log data from several sources. They are essential to the automation of incident response and threat detection.