What is logging?

Logging is the process of recording events and activities that occur in a device or application. Any event—such as user logins, system errors, application crashes, permission changes, and more—gets recorded in a system or application in the form of logs. Logging systematically records and manages these logs so that they can be used for troubleshooting, as well as operational and security purposes.

In the early phases of cyberattacks, threat actors usually focus on gaining a firm foothold of the network. This initial phase often involves exploiting vulnerabilities and using attack vectors to gain unauthorized access. Once inside, attackers may attempt to move laterally, escalate privileges, or establish persistence.

But how can security admins know that something suspicious is going on in the network? The answer is logs. Security admins monitor logs from some or all log sources in the network. Here are some of the critical resources from which log data is collected and analyzed:

Firewalls

Firewall logs contain critical information that plays a key role in ensuring a network's security. The firewall logs give insights into network traffic such as denied connections, allowed connections, configuration changes, and configuration errors, as well as details about the addition and deletion of users and their privilege level changes.

By analyzing firewall logs, admins can discover malicious activity in the network, optimize firewall rules, and strengthen their network's security boundaries.

Proxies and other web filters

Logs from proxies and other web filters are made up of the log data from users and applications that use your network. Apart from website requests from users, these logs also capture application and service requests. Proxy logs can extract information like the destination IP, destination port, user agent, device action, and a lot more. Capturing this information provides insights into what's happening in the network.

Organizations can find major issues in their network by monitoring the various user-agent strings and scrutinizing any abnormalities.

Windows events

The Windows event log is a complete record of everything that happens in a Windows operating system. Some of the log info collected includes Windows application logs, security and system logs, DNS server logs, Directory Server logs, and File Replication Service logs.

Collecting the Windows event logs ensures that any anomalies or strange behavior is immediately flagged and brought to notice. It ensures better server security, workstation security, and diagnostics for problems with malfunctioning hardware components.

For example, pass-the-hash is a popular attack amongst hackers because it's used to gain account access without a password. You will need to look for NTLM Logon type 3 event IDs—i.e. 4624 (success) & 4625 (failure)—for this attack.

Another common trait among hackers is that they try to hide their presence. Looking out for event IDs 104 (event log cleared) and 1102 (audit log cleared) can help you find their presence in your network.

Applications

An application log is a file with the information of all the events that occurred within an application. Some of the common components in application logs include context information, timestamps, and log levels.

You can collect logs from web server applications like IIS and Apache, databases including MS SQL and Oracle,DHCP-based applications, and others.

Application logs help you to identify and correct issues related to the performance and security of the applications. It also helps you detect unauthorized file access and data manipulation attempts by users.

A log collection tool can help you collect different types of logs from multiple sources and unify them with ease. Using a comprehensive log collection tool like ManageEngine's EventLog Analyzer can also help you organize and sort through your logs to gain valuable insights about your organization's security posture. Check out the solution's log collection capabilities here.

Methods for log collection

Now that we've mentioned the different sources from which logs can be collected, it's important to note that logs can also be collected using different methods. Two of the most common mechanisms for collecting log data are agentless and agent-based log collection. Some of the other common log collection techniques include API-based log collection, WMI-based log collection, and SNMP traps.

Agentless log collection

In agentless log collection, the logs generated on every device are collected without an agent. The device or application where the log is generated will directly send the log data to a central server. The transmission will be secured using protocols such as TCP and HTTPS.

API-based log collection

In this method, an API is used for querying and transferring log data to a secure server. You can also use APIs to collect logs and send them to a third-party log analytics tool to analyze the log data.

SNMP traps

An SNMP trap is made by an SNMP-enabled device, which is the agent, and is sent to a collector. The collector is informed in real time by the SNMP trap whenever an important event happens, primarily collecting events for management and monitoring.

Agent-based log collection

This log collection mechanism uses an agent that resides within the device. The agent collects and securely sends the log data to a central server. The advantages of using agent-based log collection is that log collection filters can be applied using the agents to limit how much bandwidth the process consumes. Agent-based log collection is usually used in networks within a secure zone and where communication is restricted.

WMI event logging

Windows Management Instrument (WMI) event logging is a method used to collect logs from the Windows environment. The Event Tracing for Windows (ETW) is done by WMI event logging. They collect details about events, diagnostic data, errors, and various other activities in your network.

Why is logging important?

Establishing baselines

By analyzing the logs continuously, organizations can define a baseline of normal system behavior. Any deviation from this established normal behavior can signal a security anomaly.

Event monitoring

It helps organizations see the overall picture of what's happening within their network and improve their operational efficiency.

Prompt incident response

Logging helps in the identification of event patterns that may signal a potential security breach. Upon detection, alerts can be generated to prompt immediate action.

Ensuring compliance

Compliance mandates—like PCI DSS, HIPAA, GDPR, etc.—require organizations to maintain a record of all the network logs to demonstrate their adherence to the standards.

User activity tracking

Logs play a primary role in monitoring user activities. Log data can be used to track user behavior and detect insider threats proactively.

Forensic analysis

In the case of a security breach, logs serve as the source for forensic investigation. They enable security teams to trace back and spot the root cause of the breach and collect all the required evidence.

How can EventLog Analyzer help?

EventLog Analyzer is ManageEngine's comprehensive log management solution designed to help organizations efficiently collect, analyze, and manage log data from various sources. It connects dots, making sense of the vast and diverse log data generated by your network, servers, and applications.

This real-time log correlation doesn't just stop at detection. It immediately triggers alerts to notify you of critical events. These alerts act as a proactive shield, ensuring swift responses to security breaches or operational issues.

Furthermore, EventLog Analyzer goes beyond mere log management. EventLog Analyzer can be upgraded into a full-fledged SIEM solution, which can provide a comprehensive overview of your network's security posture.

What's next?