Incident Response: Phishing Attempt Detection
False Positive:
Details: The alert signaled a potential phishing attempt, which, upon investigation, proved to be a false positive. The reported emails were legitimate communications related to a company-wide survey.
Example: After analyzing the characteristics that triggered false positives, the SOC refined email security rules to better differentiate legitimate company-wide survey communications from potential phishing attempts.
False Negative:
Details: A separate incident involved a phishing email successfully bypassing existing controls, delivered to employee inboxes without being flagged by initial detection mechanisms.
Example: The investigation revealed a new evasion technique in the phishing email. The SOC updated email security solutions to enhance recognition and blocking of similar threats in the future.
True Positive:
Details: Successful detection and blocking of a malware-laden email attachment, preventing potential harm to the organization.
Example: The incident was used as a success case for validation. The SOC reviewed response actions, identified areas for improvement, and incorporated lessons learned into future incident response plans. Validation and Resolution
False Positive Validation:
Action: Thorough review and refinement of email security rules. Details: Analysis revealed characteristics similar to phishing emails, leading to false positives. Rules were refined to reduce occurrences without compromising security.
Example: The SOC conducted a comprehensive review of email security rules, fine-tuning parameters to minimize false positives while maintaining a high level of security.
False Negative Investigation:
Action: In-depth analysis and email security solution update. Details: Identified a new evasion technique in the delivered phishing email, prompting an update to the email security solution for improved recognition and blocking.
Example: Through detailed analysis, the SOC identified a previously unknown evasion technique and promptly updated the email security solution to enhance detection capabilities.
True Positive Review:
Action: Review of response actions and identification of areas for improvement.
Details: The incident was used as a success case for validation, and response actions were reviewed to identify opportunities for improvement.
Example: The SOC conducted a post-incident review, identifying successful response actions and areas for enhancement to further strengthen incident response capabilities.
Adjustments to Detection and Response Strategies
Enhanced Email Security Rules:
Action: Refinement of email security rules.
Details: Aimed to reduce the likelihood of legitimate communications triggering alerts while maintaining a high level of security.
Example: The SOC refined rules to consider context and sender behavior, minimizing the chances of legitimate communications being flagged erroneously.
Machine Learning Model Update:
Action: Collaboration with data scientists for model update.
Details: Machine learning models used for phishing detection were updated to recognize the new evasion technique, enhancing overall accuracy.
Example: Data scientists collaborated with the SOC to update machine learning models, incorporating insights from the latest phishing threats.
Training and Awareness:
Action: Enhancement of training programs for SOC analysts.
Details: Emphasis on recognizing new evasion techniques and refining investigative procedures to bolster the team’s capabilities.
Example: SOC analysts underwent training sessions focusing on the latest evasion techniques employed by threat actors, improving their ability to identify and respond to evolving phishing threats.
Continuous Monitoring and Feedback Loop
Action: Implementation of continuous monitoring mechanisms.
Details: Established processes to closely track the performance of detection systems, ensuring adaptability to emerging threats.
Example: The SOC implemented continuous monitoring tools and processes to track the effectiveness of email security solutions, promptly identifying and addressing any anomalies.
Cross-Functional Collaboration
Action: Reinforcement of collaboration with IT and cybersecurity awareness teams.
Details: Shared insights from false positives and negatives to enhance overall cybersecurity education and awareness initiatives.
Example: The SOC collaborated with IT and cybersecurity awareness teams, sharing insights to improve employee awareness and response to phishing threats.
Periodic Tabletop Exercises
Action: Conduct periodic tabletop exercises.
Details: Simulated scenarios involving phishing attacks with varying levels of sophistication to identify gaps and refine response strategies.
Example: The SOC regularly conducts tabletop exercises simulating phishing attacks, allowing the team to identify weaknesses, test response plans, and continuously improve.
Conclusion
The incident response to phishing attempts involved addressing false positives, updating security measures against new evasion tactics, and leveraging true positives for continuous improvement. A combination of refined rules, updated models, training, and collaboration ensured a proactive and adaptive response strategy against evolving phishing threats.