Security Operations Center (SOC) Tier 3 Analyst / Incident Responder

Key Responsibilities

• Lead advanced investigations involving ransomware, APTs, zero-day exploits, insider threats, credential theft, lateral movement, cloud compromise, on-premises systems, VDI, SaaS, API abuse, business email compromise, certificate abuse, and data exfiltration.
• Perform full lifecycle incident response including detection, triage, investigation, containment, eradication, recovery, validation, root cause analysis, and post-incident review.
• Investigate attacks spanning on-premises infrastructure, Windows and Linux servers, Active Directory, Active Directory Certificate Services (AD CS), Microsoft Entra ID, Microsoft 365, Azure, AWS, VDI, SaaS platforms, APIs, containers, Kubernetes, databases, enterprise applications, and hybrid cloud environments.
• Perform forensic analysis of on-premises systems, endpoints, servers, virtual machines, VDI, cloud workloads, identity systems, SaaS applications, APIs, databases, and network devices.
• Analyze telemetry from EDR/XDR, NDR, SIEM, firewalls, IDS/IPS, WAF, VPN, DNS, DHCP, proxy, email security, cloud audit logs, API gateways, identity providers, application logs, and operating system logs.
• Develop detections and SIEM correlation rules using Elastic Security, KQL, ES|QL/EQL, SQL, PowerShell, and Python.
• Conduct proactive threat hunting using MITRE ATT&CK, behavioral analytics, and threat intelligence.
• Provide technical leadership and mentoring to Tier 1 and Tier 2 analysts.
• Support management with reporting, including producing technical reports documenting attack timelines, root cause, IOCs, IOAs, TTPs, and recommendations.

Required Qualifications

• Expert knowledge of SIEM, SOAR, EDR/XDR, NDR, IDS/IPS, WAF, firewalls, email security, web proxies, CASB, DLP, IAM, PAM, API security, and cloud-native security technologies.
• Expert experience with Elastic Security (ELK), CrowdStrike Falcon, Microsoft Defender XDR, Defender for Endpoint, Defender for Identity, Defender for Office 365, Defender for Cloud, and Defender for Cloud Apps.
• Deep understanding of on-premises infrastructure including Windows Server, Linux, Active Directory, Active Directory Certificate Services (AD CS), VMware, Hyper-V, storage, virtualization, networking, Microsoft Entra ID, Microsoft 365, Azure, AWS, VDI, SaaS, APIs, containers, Kubernetes, databases, and hybrid cloud architectures.
• Expert knowledge of TCP/IP, DNS, DHCP, VPN, routing, switching, PKI, Kerberos, NTLM, OAuth, OIDC, SAML, JWT, and certificate-based authentication.
• Advanced proficiency investigating on-premises systems, cloud environments, endpoints, servers, identity platforms, VDI, SaaS applications, APIs, databases, enterprise applications, and AD CS/PKI-related attacks.
• Expert proficiency with KQL, ES|QL/EQL, SQL, PowerShell, Python, and Bash.
• Deep knowledge of MITRE ATT&CK, MITRE D3FEND, Cyber Kill Chain, NIST CSF, NIST 800-61, OWASP Top 10, malware analysis, digital forensics, and attacker methodologies.
• Minimum two certifications such as GCFA, GCFE, GCIH, GCIA, GREM, CISSP, SC-200, SC-100, AWS Certified Security – Specialty, or equivalent.
• Bachelor's degree in Cybersecurity, Computer Science, Information Technology, or equivalent experience.

Preferred Qualifications

• Experience in financial services or another highly regulated industry.
• Experience investigating enterprise incidents across Microsoft 365, Azure, AWS, Elastic, CrowdStrike, and hybrid environments.
• Experience supporting DFIR engagements involving ransomware, nation-state threats, insider threats, enterprise-scale incidents, and Active Directory Certificate Services (AD CS) abuse.

Experience Requirements

• Minimum 8 years of progressive cybersecurity experience.
• Minimum 6 years of hands-on Security Operations Center experience.
• Minimum 4 years leading complex enterprise incident investigations.
• Minimum 2 years performing advanced digital forensics, threat hunting, and detection engineering.
• Proven experience independently investigating incidents from initial alert through full remediation across on-premises infrastructure, enterprise networks, endpoints, identity platforms, Microsoft 365, Azure, AWS, VDI, SaaS applications, APIs, Elastic Security, hybrid cloud environments, and PKI/AD CS.

OneMain Holdings, Inc. is an Equal Employment Opportunity (EEO) employer. Qualified applicants will receive consideration for employment without regard to age, ancestry, citizenship status, color, creed, culture, disability, ethnicity, gender, gender identity or expression, genetic information or history, marital status, military status, national origin, nationality, pregnancy, race, religion, sex, sexual orientation, socioeconomic status, transgender or on any other basis protected by law.