Senior Security Penetration Tester

EPAM Systems Inc; Kraków; Hybrid; PLN 260,000 - 380,000; Full time

Job summary

EPAM Systems Inc is seeking a research-minded Senior Security Penetration Tester focused on OT/ICS security, exploit development, and AI/LLM security. You will break real industrial environments safely, write exploits, and test LLM applications and agentic AI systems.

You will deliver engagements end-to-end and contribute to client zero-day programs, building AI-driven tooling to scale capabilities. The role requires deep technical breadth, the ability to explain findings to engineers and

Qualifications

• Bachelor's degree in Computer Science, Information Security or related field, or equivalent practical experience.
• 5+ years of hands-on penetration testing and offensive security experience with depth in OT/ICS security, exploit development or AI/LLM security.
• Experience testing OT/ICS environments, and safety-first testing practices.
• Proven exploit-writing ability with CVE credits, advisories or talks.
• Hands-on experience testing LLM applications or agentic AI systems and understanding of model/tool permissions.
• Strong programming skills in Python and C/C++, with knowledge of x86/x64 and ARM assembly; Bash/PowerShell.
• Proficiency with reverse engineering and debugging tools (IDA Pro, Ghidra, Binary Ninja, WinDbg, GDB with pwndbg/GEF).
• Familiarity with fuzzers (AFL++, libFuzzer, boofuzz) and offensive tooling (Burp Suite, Metasploit, Nmap) and Wireshark.

Responsibilities

• Plan and perform safety-first penetration tests of OT/ICS environments including policy-compliant segmentation testing.
• Assess PLCs/RTUs/HMIs/SCADA servers and engineering workstations across major vendors.
• Test industrial protocols for authentication, integrity and logic weaknesses.
• Build digital-twin labs to validate attack paths prior to production testing and follow engagement rules.
• Map findings to ISA/IEC 62443, NIST SP 800-82 and MITRE ATT&CK for ICtS with practical remediation guidance.
• Conduct vulnerability research on binaries, firmware, embedded/IoT devices, and enterprise software using various analysis methods.
• Write PoCs and weaponized exploits for memory corruption and logic flaws; identify authentication bypass vectors.
• Attack LLM applications and agentic AI systems; evaluate model, retrieval, tools and permissions impact.
• Contribute original research to client zero-day program and help build AI-driven tooling to scale offense.
• Deliver client engagements end-to-end and communicate findings clearly to engineers and executives.

Skills

Python

C/C++

Reverse engineering

Fuzzing

Exploit development

OT/ICS security

AI/LLM security

Attack testing

Communication with engineers/executive

Education

Bachelor's degree in Computer Science or related field

Tools

IDA Pro

Ghidra

Binary Ninja

WinDbg

GDB

pwndbg/GEF

Burp Suite

Metasploit

Nmap

Wireshark

Job description

We are looking for a research-minded Senior Security Penetration 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 client's zero-day program, and help build the AI-driven tooling that scales our offensive capability. The role suits someone who enjoys going deep on hard targets and can explain what they found to both engineers and executives.

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 (e.g., Rockwell/Allen-Bradley, Siemens, Schneider Electric) and SCADA platforms (e.g., VTScada, Ignition, AVEVA/Wonderware)
• 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; 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 ICtS h 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 (coverage-guided, protocol-aware and grammar-based)
• Write reliable proof-of-concept and weaponized exploits for memory corruption (stack/heap overflows, use-after-free, type confusion), logic flaws and authentication bypass
• Attack LLM applications and agentic AI systems, assessing how models, retrieval, tools and permissions combine to create attack surface
• Contribute original research to the client's zero-day program and help build AI-driven tooling that scales offensive capability
• Deliver client engagements end to end and communicate findings clearly to both engineers and executives

Requirements

• Bachelor's degree in Computer Science, Information Security, Electrical/Control Engineering or a related field, or equivalent practical experience
• 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
• Background in OT/ICS penetration testing on real industrial environments or high-fidelity labs, with a strong grasp of safety-first testing practices
• Showcase of exploit-writing ability, evidenced by original vulnerability research such as 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 an understanding of how models, retrieval, tools and permissions combine to create attack surface
• Strong programming skills in Python and C/C++, with working knowledge of x86/x64 and ARM assembly; Bash/PowerShell required
• Proficiency with reverse engineering and debugging tools such as IDA Pro, Ghidra and Binary Ninja, alongside WinDbg and GDB with pwndbg/GEF
• Competency in fuzzers (AFL++, libFuzzer, boofuzz) and offensive tooling (Burp Suite, Metasploit, Nmap), as well as Wireshark with ICn
• Familiarity with industry standards and frameworks, including OWASP Top 10, CVE/CWE and OSSTMM, along with NIST, MITRE ATT&CK, ISA/IEC 62443 and MITRE ATLAS
• Excellent written and spoken English; able 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 (e.g., on-site OT assessments) when required

Nice to have

• Knowledge of Rust or Go
• Relevant offensive security certifications (considered a plus, not a substitute for demonstrated skill)

We offer

• We gather like-minded people:
  • Top tech minds driving innovation in AI, cloud and digital platform modernization
  • Supportive team and agile, startup-like culture
  • Hybrid by design mode and opportunity to work remotely within Poland
  • Chance to work abroad for up to 60 days annually
  • Business-driven relocation opportunities
• We provide growth opportunities:
  • Career development programs
  • Thought leadership, mentoring, soft skills and well-being programs
  • Certification (Anthropic, Gemini, GCP, Azure, AWS)
  • English classes
• We cover it all:
  • Stable pay
  • Participation in the Employee Stock Purchase Plan with a 15% discount
  • Benefits package (health insurance, multisport, shopping vouchers)
  • Referral bonuses up to $2,000
  • Offices featuring entertainment and relaxation zones, table tennis and football, free snacks, coffee and more
  • Corporate, social and well-being events
• Please, note:
  • Benefits listed above are available to employees only
  • We are open for working with Contractors. Terms of B2B cooperation agreements are agreed individually
  • We will reach out to selected candidates exclusively

EPAM is global leader in AI transformation engineering and integrated consulting, serving Forbes Global 2000 companies and ambitious startups. With over thirty years of expertise in custom software, product and platform engineering, we empower our clients to become AI‑Native enterprises, driving measurable value from innovation and digital investments.