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The OPST is a certification of applied knowledge designed to improve the work done as a professional security tester. This is an important certification for those who want or need to prove they can walk the walk in security testing, the discipline which covers network auditing, ethical hacking, web application testing, intranet application testing, and penetration testing. And it is a critical, eye-opening class for security auditors, network engineers, system and network administrators, developers, network architects, security analysts, and truly anyone who works in IT from systems to networks.

OPST certified personnel are in-demand around the world as the need to assure one can provide technical security skills and ability grows. This challenging certification is provided in technical schools, colleges, universities, and through training partners, all certified by ISECOM to assure consistency, quality, and focus. For this reason, ISECOM can assure any organization on a certified person's level of applied security testing knowledge and their exposure to the appropriate and ethical behavior outlined in the OSSTMM's Rules of Engagement.

OSSTMM Professional Security Tester Accredited Certification (OPST) - London

Certified Profiles

OPST certified professionals work in some of the world's top corporations as internal and external testers, security analysts, information security experts. Here is a small sample of the circa 5000 individuals that help protect our increasingly unstable digital world:

Security Engineer - Facebook
Technical Advisor - Alvarez & Marsal
Advisory Consultant IR - RSA - The Security Division of EMC
Head of the Cyber Security and Digital Forensics division - Tesla Consulting
Head of Information Security - MSC Cruises
Computer Engineer - Banca d'Italia
Security Architecture Team Leader - Turk Telekom
Penetration Tester - Barclays
Research Director - NCC Group
Deputy CISO - Forcepoint
Sr. Security Researcher - SecureWorks
Information Security Manager - Europe - Publicis Groupe
Cyber Security Practice Lead - Global  - Symantec
Cyber Security Professional - Manager - Accenture
Head of IT Operation - Repower
Head of Infrastructure & Networking - Thyssenkrupp
ISEC GS - Siemens AG
senior business consultant information security - adidas Group
Senior ICT and Network Security Specialist - Telecom Italia
IT Security Architect - Fastweb
Service Line Manager - Akamai Technologies
Enterprise Security Manager - Banc Sabadell Information Systems
Account Chief Technologist - Hewlett Packard Enterprise
Security Engineer IAM - RBS Services (Switzerland) Ltd.
Manager of Advanced Security Center - Ernst & Young
Information Security Analyst - Northrop Grumman
Automation Technology System Senior Expert - Pfizer
Security Analysis - Test and Compliance Unit Manager  - Barikat Bilisim
Lead Product Security Engineer - Network and Datacenter  - Salesforce
CSE for Advanced Threat Solutions - Cisco
Head of Cyber Threat Detection and Response - IAG
Sr. Engineering Technical Program Manager - Twitter
Principal Security Analyst - GReAT Team - South Europe  - Kaspersky Lab
Security Solutions Architect - HP ESP - Security - Hewlett-Packard
CISO & IT Manager - Gemalto
IT Security Consultant - Swisscom
Manager - IRM - IT Advisory  - KPMG
Manager - Threat Analysis  - Trend Micro
Security manager - HSBC
Head of Security Red Team - POST Luxembourg
Associate Director - IT Risk Management & Security  - Merck
Security Researcher - McAfee MVM - Intel Security
Security Engineer - DefenseStorm - Inc.
Consultant HPC - Amazon Web Services
Software Development Engineer - Rapid7
Head of Provider Management - Swiss Confederation
Principal System Engineer - ACI Worldwide
Junior Network Engineer - Ericsson
Senior Systems Engineer - DELL EMC
IT Senior Security Consultant - IBM
Senior System Engineer - Nokia


OPST certification requires a grade of D (60%) or better for certification. Each certificate is accompanied by a transcript which reflects the grade and areas of strengths and weaknesses. The grade of A (90% or better) includes a seal of excellence.

The exam requires mastering the application of the following security testing skills:

Rules of Engagement
  • The ability to apply the rules of engagement, as outlined in the latest version of the OSSTMM, to various scenarios.
  • The ability to properly and legally determine the target scope through public services, determine types of hosting, service providers, peering partners, and any active intrusion detection or service redundancy implementations.
  • The ability to quickly assess flaws or limitations in the network between the tester and the target, gage appropriate testing speed and efficiency, decipher network and service protection techniques and loss controls. The ability to quickly and scientifically develop new test types and evaluations to assess uncalculated test responses and anomalies.
  • The ability to accurately and efficiently send and receive packets of any type in the myriad of ways required by the OSSTMM. The ability to use any appropriate packet tool while understanding the functioning of the tool and its limitations. The ability to recognize enumeration techniques, flaws, and fallacies.
  • The ability to operate within established loss controls (ie. ssl encryption, load balancing, port forwarding, NAT, etc.) to identify services, applications, and protocols. The ability to properly and independently choose the appropriate tool and protocol for each test.
  • The ability to correctly and accurately identify operating system types and versions through packet and service data correlation with and without the use of fingerprinting tools. The ability to discover unknowns and satisfactorily explain anomalies in a scientific manner.
  • The ability to apply scientific methodology to the process of vulnerability and weakness identification and verification for an accurate determination of security limitations. The ability to map known exploits to services. The ability to discover exploits of known vulnerabilities for verification. The ability to classify new security limitations appropriately.


The general course is designed to teach resourcefulness, the scientific method, and the OSSTMM methodology through security testing exercises with an internet-based test network.
While practicing elements of security testing, the student is prepared to manage the daily changes in security knowledge with the fundamentals of critical security thinking.
The general course design is as an all-practice course to support the provided theory. It is to learn how to do security testing properly, factually, and scientifically through coaching, examples, and skill tests.
The scope of the exam requires self-sufficiency and resourcefulness, therefore the student can expect the training to focus on mastering the topics efficiently. The class prepares the student for successfully navigating the exam and to successfully apply it immediately on the job.
ISECOM provides certification of course trainers and certification of the students who successfully pass the exam. LiquidNexxus is authorised and certified under the ISECOM Academic Alliance program.
Join an elite group of circa 5000 certified OPST professionals worldwide! 100% of OPST graduates are in employment.
It's the perfect "landing" certification to assure a candidate can start doing the from day 1, making it one of the most effective and practical certifications for security testing. 



The exam acknowledges the skill and ability to apply security and networking knowledge in a scientific manner as required for testing data network security according to the OSSTMM as well as certify ones ability to work professionally as an OSSTMM Auditor or any other facet within the discipline of security testing.

The OPST exam requires a total of 140 answers within 4 hours. The purpose of the exam is to show the extent of security testing accuracy while maintaining efficiency. While it is an open book exam, no communication of any type is allowed. Each question is in the format of multiple-choice multiple-answer. The exam combines paper-based questions with real-time tests performed over the internet of a single vector (internet to DMZ). The choice of tools, materials, and techniques is made by the test taker at the time of the exam.


ISECOM recommends students have good knowledge of how networking protocols work, a good understanding of how various security devices and programs work, a user level skill with LINUX, and basic experience with server operations/administration particularly in setting up and running daemons and services.

It is important the student selects a training course right for their skill level. Longer courses will provide a great deal more practice, examples, and coaching while shorter classes are more suited to those with more practical experience. Classes range from as much as 60 hours over 30 days to as short as 8 hours in a single day. Talk with the regional ISECOM Certified Training Partner for assistance in choosing the right length of class.



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Rules of Engagement & Ethics

security tester must understand and comply with ethical and legal considerations

Testing Methodology

An overview of the phases of testing Induction, Interaction, Inquest, Intervention

Error Handling

Understanding and Defining Error & Exception Handling

Definitions & Methodology

Combining 4P and the Trifecta, OSSTMM 3 Test Types, Dynamics of Testing, Security Testing in Practice, Security Testing vs Hacking, Risk Assessment Values (RAVs), Technical Preparations

Testing Tools Overview

Traceroute, Dig, Whois, Nmap, Hping3, Ncat, TCPDump, WinDump, Metasploit, Armitage, BackTrack, Kali, Wireshark

Understanding Protocols & Vectors

Ports and Services, TCP/UDP/ICMP/ARP, Attack Points & Vectors

Testing in Practice

Scouting, Segregation Review, Exposure Verification, Rules, Logistics, Visibility, Assesments

Testing in Practice

Enumeration, Port Scanning, Exposure Enumeration, Services Identification, System Identification

Testing in Practice

Access Testing, Vulnerability Research, Vulnerability Testing, Application Testing

Security Testing (OSSTMM)

Internet Application Access Testing, Controls Testing, Access Testing

Security Testing (OSSTMM)

Internet Application Testing, Subjugation Testing, Router Access Testing

Security Testing (OSSTMM)

Firewall Access Testing, IDS Access Testing, Privileges Testing

Security Testing (OSSTMM)

Containment Measures Testing, Password Cracking, Survivability Testing


Location is disclosed to registered participants only.


Next Sessions

LiquidNexxus regularly hosts open training sessions globally, below is a list of courses related to this course which are currently scheduled. If your region is not listed or you would like to discuss inhouse training or partnership please contact us.

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