Senior Penetration Tester
CoStar GroupVirginia, United States
Posted May 12, 2026
Full Time
About the Company
CoStar Group (NASDAQ: CSGP) is a global leader in commercial real estate information, analytics, online marketplaces and 3D digital twin technology. Founded in 1986, CoStar Group is dedicated to digitizing the world’s real estate, empowering all people to discover properties, insights, and connections that improve their businesses and lives. CoStar Group’s major brands include CoStar, a leading global provider of commercial real estate data, analytics, and news; LoopNet, the most trafficked commercial real estate marketplace; Apartments.com, the leading platform for apartment rentals; and Homes.com, the fastest-growing residential real estate marketplace. CoStar Group’s industry-leading brands also include Matterport, a leading spatial data company whose platform turns buildings into data to make every space more valuable and accessible, STR, a global leader in hospitality data and benchmarking, Ten-X, an online platform for commercial real estate auctions and negotiated bids and OnTheMarket, a leading residential property portal in the United Kingdom. CoStar Group’s websites attracted over 134 million average monthly unique visitors in the fourth quarter of 2024, serving clients around the world. Headquartered in Arlington, Virginia, CoStar Group is committed to transforming the real estate industry through innovative technology and comprehensive market intelligence. From time to time, we plan to utilize our corporate website as a channel of distribution for material company information. For more information, visit CoStarGroup.com.
Job Description
Senior Penetration Tester position at CoStar Group, responsible for leading penetration tests on web applications and infrastructure, developing test plans, and recommending remediations.
Requirements
- Bachelor's Degree from an accredited university in Computer Science, Cybersecurity, or related field.
- 6 years of experience in a technical role, with at least 3 years focused on penetration testing or offensive security.
- Demonstrated experience with web application and API penetration testing, including identifying and exploiting attack chains.
- Scripting and programming proficiency in Python, PowerShell, or similar.
- Understanding of defense-in-depth principles and ability to recommend layered mitigations.
Benefits
- 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
- Access to CoStar Group’s Employee Resource Groups
- Complimentary gourmet coffee, tea, hot chocolate, fresh fruit, and other healthy snacks
