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Salary
≈ $91k – $188k per year (Estimated)
Location
Hybrid (Arlington, San Diego, Richmond, United States)
Seniority
Staff · 5+ years exp
Visa
No sponsorship (stated in the posting)

Confirmed on the employer's own hiring board on Oct 15, 2026. First seen by Alion on Oct 17, 2025. CoStar Group scores B on the Alion truth index.

Overview
Company
Impact
Profile match
CoStar Group is a real estate information, analytics and online marketplace company headquartered in Arlington, Virginia, behind the CoStar database and brands such as LoopNet, Apartments.com, Homes.com, Land.com, Ten-X, BizBuySell, STR, Matterport and OnTheMarket. Founded in 1987 by Andrew Florance, it is listed on NASDAQ and in the S&P 500, with major offices in Richmond, Irvine, London, Paris and Sydney serving brokers, owners, lenders, landlords and home buyers. It hires software, AI and security engineers, field researchers, account executives and sales associates, product marketers, recruiters and finance and lease administration staff.
Lead Detection and Response Security Engineer

Job Description

Overview

CoStar Group is a leading global provider of commercial and residential real estate information, analytics, and online marketplaces. Included in the S&P 500 Index, CoStar Group is on a mission to digitize the world’s real estate, empowering all people to discover properties, insights and connections that improve their businesses and lives.

We have been living and breathing the world of real estate information and online marketplaces for over 35 years, giving us the perspective to create truly unique and valuable offerings to our customers. We’ve continually refined, transformed and perfected our approach to our business, creating a language that has become standard in our industry, for our customers, and even our competitors. We continue that effort today and are always working to improve and drive innovation. This is how we deliver for our customers, our employees, and investors. By equipping the brightest minds with the best resources available, we provide an invaluable edge in real estate.

In this role, you'll communicate and reinforce security concepts to technical and non-technical audiences within the CoStar Enterprise. The ideal candidate will have experience implementing, using and updating standard security software in the areas of vulnerability scanning/management, leading remediation efforts, end-node security, security tool integration and orchestration for incident response.

As the security section grows, so will the tools and the Lead Security Engineer will be the person charged with implementing them. The successful candidate will be a self-starter motivated to learn new technologies and tools and assist in moving security forward as it is implemented within the CoStar Enterprise.

This position can be located in Arlington or Richmond, VA and is in office Monday through Thursday and work from home on Friday.

Responsibilities

  • Incident handling - serve as the incident response coordinator to oversee all incident response activities and ensure timely and successful resolution of incidents across various business verticals
  • Develop, mature and lead incident response functions and reporting of findings
  • Lead technical security assessments (network, application, database) for existing and newly acquired businesses or services and collaborate with other teams to adjust security configurations and architecture
  • Facilitate quarterly incident response tabletop exercises and updating of the Incident Response Plan
  • Team expert on Mitre Att&ck, tools, techniques, and practices of cyber attackers which you use to drive the overall strategy of the incident response team.
  • Ability to define and develop platform automations to increase efficiency in responding to observed threats.
  • Familiarity and comfort with at least one scripting language and basic understanding of CI/CD practices.
  • Coordinate, performance and derive work from the security review and monitoring of the production environment setup permissions of users, open ports/services and overall network setup
  • Ability to examine network, server, and application logs with forensic depth to determine trends and identify security incidents, and train and mentor others to deepen their skills
  • Use security tools to audit infrastructure, detect issues and coordinate remediation of any issues
  • Develop and mature threat hunting practices in the CoStar enterprise
  • Collaborate with other teams to remediate discovered deficiencies, and develop and improve network and endpoint security configuration procedures
  • Participate in 24x7 on-call rotation

Basic Qualifications

  • Bachelor’s Degree required from an accredited, not for profit university or college.
  • A track record of commitment to prior employers
  • One or more security certification such as SANS/GIAC, CISSP, CISM, GIAC Certified Incident Handler (GCIH), Certified Expert Incident Handler (CEIH) or equivalent
  • 8+ years in Information Technology, with 5+ years of cyber security experience.
  • Scripting/programming skills (Perl, Python, PowerShell)
  • Experience with Windows Server 2012/2016 /2019 and Active Directory

Preferred Qualifications and Skills

  • Excellent oral and written communication skills to work effectively with others regardless of departmental or geographic boundaries
  • Ability to work on a cultural diverse team that spans international time zones and foster an environment of inclusions and participation with all team members
  • Experience with Microsoft Security tooling (Defender, Sentinel, EOP etc.) a plus
  • Ability to produce detailed technical documentation
  • Proficiency with PC software applications, E-Mail, and job associated applications/systems to expediently process work
  • Requires good organization skills to produce quality work, within required specifications, and within scheduled timelines
  • Excellent customer service skills

What’s in it for You

When you join CoStar Group, you’ll experience a collaborative and innovative culture working alongside the best and brightest to empower our people and customers to succeed.

We offer you generous compensation and performance-based incentives. CoStar Group also invests in your professional and academic growth with internal training, and tuition reimbursement.

Our benefits package includes (but is not limited to):

  • Comprehensive healthcare coverage: Medical / Vision / Dental / Prescription Drug
  • Life, legal, and supplementary insurance
  • Virtual and in person mental health counseling services for individuals and family
  • Commuter and parking benefits
  • 401(K) retirement plan with matching contributions
  • Employee stock purchase plan
  • Paid time off
  • Tuition reimbursement
  • On-site fitness center and/or reimbursed fitness center membership costs (location dependent), with yoga studio, Pelotons, personal training, group exercise classes
  • Access to CoStar Group’s Employee Resource Groups
  • Complimentary gourmet coffee, tea, hot chocolate, fresh fruit, and other healthy snacks

We welcome all qualified candidates who are currently eligible to work full-time in the United States to apply. However, please note that CoStar Group is not able to provide visa sponsorship for this position.

The final salary or hourly rate offered for this role will fall within the range set forth below based on a variety of factors, including but not limited to, geographic location, skills, and competencies.

Base Compensation: 147,000 - 247,000 Annually

CoStar Group is an Equal Employment Opportunity Employer; we maintain a drug-free workplace and perform pre-employment substance abuse testing

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