C1000-162 - IBM Security QRadar SIEM V7.5 Analysis

Understanding the Scenario: The detection of unauthorized high-rate traffic for transferring outbound mail via port 25 indicates potential misuse or compromise of the source system.

Appropriate Response:

Investigate the Offense: The first step is to continue investigating the offense to gather more details about the source system and the nature of the traffic.

Organizational Response Processes: Following the organization’s established response processes ensures that appropriate actions are taken to mitigate the threat, which may include blocking the traffic, isolating the system, or further forensic analysis.

Avoiding Incorrect Actions:

Adding to Building Blocks: Adding the IP address to the Host Definition Mail Servers building block would incorrectly categorize the unauthorized system as a legitimate mail server.

Allowing Traffic: Submitting a request to the firewall team to allow this traffic would permit unauthorized activity and potentially exacerbate the security issue.

False Positive Wizard: Using the False Positive Wizard is not suitable as this situation represents a genuine security concern rather than a false positive.

Reference Confirmation: According to IBM QRadar documentation, the recommended action in such scenarios is to follow the organization’s incident response processes to ensure a thorough and effective response.

References:

IBM QRadar documentation on incident response and handling unauthorized activities.

Here's why this is the most effective approach:

False Positive Reduction: The goal is to stop legitimate traffic from triggering offenses. This requires fine-tuning the rules generating those offenses.

Building Blocks: Rules are housed within building blocks in QRadar's hierarchical rule structure. The Custom Rules Editor is the tool to modify them.

Event-Based Tuning: The optimal approach is to target the specific event that's causing the false positives, making the solution more precise.

Within IBM Security QRadar's Ariel Query Language (AQL), functions play a crucial role in manipulating data, performing calculations, and formatting results for more insightful analysis. Among the options provided, "LOWER" (C) and "STRLEN" (D) are valid AQL functions used for formatting and calculations, respectively. The "LOWER" function is used to convert a string to lowercase, which can be useful for case-insensitive comparisons or data normalization. The "STRLEN" function calculates the length of a string, providing valuable information about the data content, such as detecting unusually long or short values that might indicate anomalies or issues within the event or flow data .