Senior Security Tester (Penetration Testing)

EPAM Systems; United States; Remote; USD 180,000 - 240,000; Full time

Job summary

EPAM Systems Inc. seeks a research-minded Senior Security Tester operating at the nexus of OT/ICS security, exploit development, and offensive testing of AI systems.

You will break real industrial environments safely, write exploits, and assess LLM applications with attacker-like methodology. You will deliver client engagements end-to-end, contribute original research to zero-day programs, and help build AI-driven tooling to scale offensive capability while adhering to safety and engagement

Qualifications

• Bachelor's degree or equivalent practical experience in CS/InfoSec/Engineering.
• 5+ years of hands-on pentesting and offensive security, with OT/ICS, exploit development or AI/LLM focus.
• Experience testing LLMs or agentic AI systems and understanding attack surface.
• Proficiency in Python, C/C++, assembly, scripting languages and debugging tools.
• Knowledge of ISA/IEC 62443, NIST, MITRE ATT&CK and related security frameworks.

Responsibilities

• Plan and execute safety-first penetration tests of OT/ICS environments.
• Assess PLCs/RTUs/HMIS/SCADA across vendors.
• Test industrial protocols for authentication and integrity weaknesses.
• Build lab/digital-twin replicas to validate attack paths.
• Map findings to security frameworks and provide remediation guidance.
• Conduct vulnerability research on binaries, firmware, and web apps.
• Write proof-of-concept exploits for memory corruption and bypasses.
• Deliver findings clearly to engineers and executives.

Skills

Python

C/C++

x86/x64

ARM assembly

Bash/PowerShell

Reverse engineering

Fuzzing

Penetration testing

OT/ICS security

Education

Bachelor's degree in Computer Science or related field

Electrical/Control Engineering or Information Security

Tools

IDA Pro

Ghidra

Binary Ninja

Burp Suite

Metasploit

Nmap

Job description

We are seeking a research-minded Senior Security Tester who sits at the intersection of three disciplines: operational technology (OT/ICS) security, exploit development and zero-day discovery, and offensive testing of AI and agentic systems. This is not a scanner-driven role — you will break real industrial environments safely, write working exploits for vulnerabilities you find yourself, and attack LLM applications and autonomous agents the way a capable adversary would. You will deliver client engagements end-to-end, contribute original research to the customer's zero-day program, and help build the AI-driven tooling that scales our offensive capability.

Responsibilities

• Plan and execute safety-first penetration tests of OT/ICS environments (water and wastewater, energy, manufacturing, building systems), including passive asset discovery, Purdue-model segmentation testing and IT-to-OT pivot analysis
• Assess PLCs, RTUs, HMIs, SCADA servers, historians and engineering workstations across major vendors and SCADA platforms
• Test industrial protocols such as Modbus/TCP, DNP3, EtherNet/IP/CIP, S7comm, OPC UA, BACnet and IEC 60870-5-104/61850 for authentication, integrity and logic-manipulation weaknesses
• Build and use lab or digital-twin replicas to validate attack paths before touching production, and operate strictly within client-approved rules of engagement, change windows and safety constraints
• Map findings to ISA/IEC 62443, NIST SP 800-82 and MITRE ATT&CK for IC S, with remediation guidance that is realistic for plant operations
• Conduct vulnerability research on binaries, firmware, embedded/IoT devices, web applications and enterprise software using reverse engineering, source code review and fuzzing
• Write reliable proof-of-concept and weaponized exploits for memory corruption, logic flaws and authentication bypasses
• Deliver client engagements end to end and communicate findings clearly to both engineers and executives

Requirements

• Minimum 5 years of hands-on penetration testing and offensive security experience, including significant depth in at least two of: OT/ICS security, exploit development/vulnerability research, and AI/LLM security
• Demonstrated OT/ICS penetration testing experience on real industrial environments or high-fidelity labs, with a strong grasp of safety-first testing practices
• Showcase of original vulnerability research through CVE credits, published advisories or exploits, conference talks, or high-level bug bounty/CTF results
• Hands-on experience testing LLM applications or agentic AI systems, with a working understanding of how models, retrieval, tools and permissions combine to create attack surface
• Proficiency in Python, C/C++, x86/x64 and ARM assembly, and Bash/PowerShell; Rust or Go a plus
• Proficiency with reverse engineering and debugging tools (IDA Pro, Ghidra, Binary Ninja), fuzzers (AFL++, libFuzzer, boofuzz) and offensive tooling (Burp Suite, Metasploit, Nmap)
• Familiarity with industry standards and frameworks including OWASP Top 10, CVE/CWE, OSSTMM, NIST, MITRE ATT&CK, ISA/IEC 62443 and MITRE ATLAS
• Bachelor's degree in Computer Science, Information Security, Electrical/Control Engineering or a related field or equivalent practical experience
• Excellent written and spoken English, with the ability to convey complex technical concepts to technical and non-technical audiences
• Based in Europe and eligible to work through EPAM, able to overlap with US business hours for client meetings, and available for occasional travel when required