Question

Difficulty: MediumLog Analysis and SIEM Management

During an enterprise Security Operations Center (SOC) investigation, telemetry from various log sources is ingested into a SIEM platform. Match each log snippet on the left with the corresponding event description on the right.

  • 192.168.1.50 - - [27/Jul/2026:14:32:10 +0000] "GET /login.php?user=admin' OR '1'='1" 200 4502Web application access log showing an inline SQL injection attempt against an authentication endpoint.
  • EventID: 4625, Account Name: jdoe, Failure Reason: Unknown user name or bad password, Logon Type: 3Windows Security log recording a failed network logon attempt.
  • Jul 27 14:35:01 fw01 kernel: DROP IN=eth0 OUT= SRC=10.0.0.15 DST=192.168.1.10 PROTO=TCP SPT=49152 DPT=445Perimeter firewall syslog entry depicting blocked traffic destined for Server Message Block (SMB).
  • type=SYSCALL arch=c000003e syscall=59 success=yes exit=0 pcomm="nc" exe="/usr/bin/nc"Linux audit daemon log capturing the execution of an outbound netcat process.

Answer

The correct pairings are: HTTP GET log with SQL payload matches the web application SQL injection description; Windows Event ID 4625 matches the failed network logon event; Firewall DROP entry targeting port 445 matches the blocked SMB traffic event; Linux SYSCALL audit log execve matching nc binary matches the executed netcat process description.
Each log entry contains distinctive indicators characteristic of its log source and activity type: HTTP GET request with SQL syntax indicates SQL injection; Windows Event ID 4625 indicates a failed logon; Syslog kernel DROP output targeting port 445 indicates blocked SMB traffic; and Linux auditd syscall 59 referencing /usr/bin/nc indicates netcat process execution.

Step-by-Step Solution

1
Analyze the web server access log snippet.
Identify HTTP GET method containing SQL logic syntax (admin' OR '1'='1), confirming a web application SQL injection attempt.
Log syntax matches standard Nginx/Apache log formatting with embedded web exploit strings.
2
Analyze the Windows Event log snippet.
Identify Event ID 4625 and Logon Type 3, pointing to an unsuccessful network authentication attempt.
Event ID 4625 standardly logs logon failures in Windows Security Event logs.
3
Analyze the firewall syslog snippet.
Identify action DROP and destination port 445 (DPT=445), denoting blocked SMB protocol traffic.
Firewall syslog outputs typically format dropped network traffic with directional IP/port flags.
4
Analyze the Linux auditd snippet.
Identify syscall=59 (execve) along with exe="/usr/bin/nc", pointing to process execution of the Netcat networking tool.
Linux audit daemon logs system calls related to process creation and command execution.

Key Concept

Log Identification and SIEM Telemetry Archetypes
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