Leidos' Corporate Information Security Office, reporting through the Digital sector, is seeking a Senior Cyber Defense Analyst.
This is an opportunity to join a team of highly skilled and innovative network defenders, and the best group of individuals out there. Leidos' Cybersecurity Intelligence and Response Team (CSIRT) has an immediate opening for a motivated Cyber Defense Analyst. Leidos is an international company made up of 50,000 employees that provides Defense, Intelligence and Health Products to our customers. Our goal is to stay ahead of, and maintain a technical advantage over our adversaries.
As a key part of the team, your responsibilities will include threat hunting, and tactical analysis of ongoing attacks by criminal and nation state actors. You will perform data analysis, incident response, investigative analysis, and research on existing and emerging cyber threats, particularly those directed against Leidos' global networks. You will be expected to "think like an adversary" and engage in threat hunting operations leveraging your understanding of the tactics, techniques and procedures employed by advanced threats combined with intelligence from multiple sources, and provide reporting and briefings to other teams and leadership in order to maintain appropriate levels of situational awareness.
A CSIRT That's Evolving Through Hyperautomation and Agentic AI Our CSIRT is actively maturing its operations by integrating hyperautomation and agentic AI into the detection, triage, and response lifecycle. Rather than relying solely on manual playbooks, the team is building and deploying intelligent automation that can orchestrate routine investigative steps, correlate signals across disparate tools, and accelerate the path from alert to action. This is a chance to help define what a modern, AI-augmented CSIRT looks like - combining seasoned analyst tradecraft with cutting-edge automation to outpace adversaries at scale.
PRIMARY RESPONSIBILITIES - Analyze network and host activity associated with both successful and unsuccessful intrusions by advanced attackers.
- Perform network traffic analysis utilizing raw packet data, net flow, IDS, and custom sensor output.
- Support enterprise incident response efforts.
- Leverage understanding of tactics, techniques and procedures associated with advanced threats to create and add custom signatures that mitigate highly dynamic threats to the enterprise.
- Employ advanced forensic tools and techniques for attack reconstruction and intelligence gathering.
- Proactively research emerging cyber threats. Apply analytical understanding of attacker methodologies and tactics, system vulnerabilities, and key indicators of attacks and exploits.
- Contribute to threat intelligence reports and briefings that provide situational awareness of cyber threats impacting the company's global network infrastructure, to every level of the organization.
- Participate in threat hunt operations using known adversary tactics, techniques and procedures, as well as indicators of attack, in order to detect advanced threats to the enterprise.
- Collaborate using information and knowledge sharing networks and professional relationships to achieve common goals.
- Provide on-call support for incident response efforts outside of core hours, as needed.
- Mentor junior analysts technically and conceptually
- Lead small groups within the team for discernable tasks, including projects and incident response
- Drive advanced countermeasures through to completion
- Understanding and educating the team about defending new threat vectors
REQUIRED QUALIFICATIONS - BS Degree and 8-12 years relevant experience in cyber security or network defense; or equivalent education and years of relevant experience coupled with relevant certifications (CISSP, SANS GIAC, CEH, etc.) may be considered in lieu of degree..
- Experience in conventional network/host-based intrusion analysis, digital forensics, or malware analysis.
- Experience performing "deep dive" analysis and correlation of log data from multiple sources including PCAP and forensic artifacts.
- Experience leading and contributing to incident response activities
- Strong understanding of Operating Systems and Network Protocols.
- Proficiency with Microsoft Windows administrative tools, and the Unix/Linux command line.
PREFERRED QUALIFICATIONS - Understanding of behavioral based threat models, including ATT&CK, Cyber Kill Chain, Diamond Model, etc.
- Experience with Splunk (preferred) or other SIEM-type platform
- Capable and comfortable communicating actionable threat intelligence to both technical and executive-level stakeholders.
- Familiarity with common languages (like Perl and Python) to parse logs, automate processes, and integrate systems.
- Previous experience as Threat Researcher and/or Intelligence Analyst.
- Experience with dynamic malware analysis, and reverse engineering.
- Experience in cryptography or cryptanalysis
- Experience in cyber security engineering
- Experience defending large cloud infrastructures (AWS, Azure, etc.)
- Ability to create, modify, and implement both Snort and YARA signatures.
- Published research papers at conferences or through other mediums (blogs, articles).
- Working knowledge of Computer Network Exploitation (CNE), Computer Network Attack (CNA) and Computer Network Defense (CND) tools and techniques.
- A deep understanding of advanced cyber threats targeting enterprises, along with the tools, tactics, and procedures used by those threats.
- Experience applying threat and data modeling, advanced data correlation, and statistical analysis to develop alerts, notable events, investigative dashboards, and metrics driven reports.
If you're looking for comfort, keep scrolling. At Leidos, we outthink, outbuild, and outpace the status quo - because the mission demands it. We're not hiring followers. We're recruiting the ones who disrupt, provoke, and refuse to fail. Step 10 is ancient history. We're already at step 30 - and moving faster than anyone else dares.
Original Posting:August 24, 2026
For U.S. Positions: While subject to change based on business needs, Leidos reasonably anticipates that this job requisition will remain open for at least 3 days with an anticipated close date of no earlier than 3 days after the original posting date as listed above.
Pay Range:Pay Range $107,900.00 - $195,050.00
The Leidos pay range for this job level is a general guideline only and not a guarantee of compensation or salary. Additional factors considered in extending an offer include (but are not limited to) responsibilities of the job, education, experience, knowledge, skills, and abilities, as well as internal equity, alignment with market data, applicable bargaining agreement (if any), or other law.
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