Leo Tsaousis

Security Consultant / Security Researcher

leo.tsaou@gmail.com
linkedin.com/in/leonidastsaousis
github.com/LAripping

Summary


Information security professional with proven track record in the design, delivery and leadership of consulting services, across the offence/defence spectrum.
Demonstrated challenge-driven attitude with an always expanding technical skillset, while not hesitating to undertake key business roles and responsibilities.
Always seeking opportunities to perform in-depth technical research, which has led to the discovery of significant vulnerabilities against reputable vendors, published in the domain and awarded CVE IDs.

Experience


11/2022-Present

WithSecure -

Manchester, United Kingdom


Senior Security Consultant


  • Leading the Attack Path Mapping service, designing and executing collaborative adversary simulations
  • Conducting technical research that produced open-source tooling and identified vulnerabilities, presenting findings at security conferences worldwide
  • Undertaking active line management, guiding consultants at different experience levels
  • Leading large scale attack detection exercises covering all surfaces of client organisations' digital estate
1/2024-2/2024

Cyber Peace Institute -

Globally


Cyber Piece Builder


  • Offered pro-bono security consulting services to NGOs around the world with small or no IT departments
  • Earned the Cyber Sentinel award for 5 "missions" completed and recognised as Top Builder for January 2024
  • Volunteered independently to help charities in healthcare, education and sustainable development defend against threats
  • Liaised, scheduled and delivered ad-hoc engagements such as security awareness training and proactive threat hunting
9/2022

Professional Education Provider -

(Confidential)


Training Instructor


  • Contracted by a cyber security education provider to deliver onsite security training to a foreign government department
  • Delivered 5 day training course "Systems and Networks Auditing and Monitoring"
  • Designed materials and hands-on exercises covering Web Applicatons, Networks, Windows and Unix systems
3/2022-8/2022

Hellenic Army -

Hellenic Ministry of Defence


Cyber Defence Department (Red Team)


  • Conducted internal security assessments
  • Participated in international cyber-readiness exercises commissioned by NATO
  • SOC duties on a weekly basis
  • Contributed tooling, automation scripts and improved pentest workflow procedures
9/2019-8/2021

F-Secure Consulting (MWR Infosecurity) -

Manchester, United Kingdom


Security Consultant


  • Led and delivered security assessments for domestic and global organisations
  • Experienced across all core service areas (appsec/netsec/mobsec), also delivered bespoke services such as design reviews and threat modelling exercises
  • Continuously supported F-Secure's delivery pipeline by frequently taking up scoping opportunities (2nd top scoper in the UK as of leaving date)
  • Served as the technical lead for a strategic telecommunications organisation, establishing solid relationships with client contacts and greatly improving F-Secure's business presence in the sector while raising significant revenue. Responsibilities also included oversight of all relevant projects and leading of key assessments
  • Contributed significantly to the mobile security service area, including delivery of internal mobile security training
  • Developed internal tools and methodologies to automate testing and share knowledge among the team
3/2017-7/2019

NSO Group (CS Circles) -

Limassol, Cyprus


Information Security Researcher


  • Member of the Research and Reverse Engineering (RARE) team focusing on vulnerability discovery against mobile and WiFi platforms
  • Established a versatile reverse engineering approach combining a thorough static analysis skillset and proficiency with dynamic instrumentation frameworks
  • Developed thorougly documented Proof of Concent (PoC) deliverables in several programming/scripting languages, accompanied by write-ups/HowTos both detailing efforts and concisely summarising research activities
  • Led a team of 3 researchers, preserving efficient communication with the upper management while keeping the team motivated and curating their training
  • Volunteered in and created challenges for "Pentest Cyprus" a regional CTF competition co-hosted by UClan Cyprus and the University of Cyprus
7/2016-2/2017

Intracom Telecom -

Athens, Greece


Software Engineer


  • Worked on Intracom's proposed solution for management of multiple WiFi Access Points, built on top of the OpenStack Cloud platform
  • Contributed in the development (Python & Java), deployment, and end-to-end testing/automation processes, while familiarising with cloud and SDN fundamentals
  • Investigated OpenStack's authentication mechanism ("Keystone"), identified and corrected bad security practices including passwords disclosed in the logs and web interface
  • Wrote Bash and Puppet scripts to automate the working environment setup

Certifications


4/2021

Offensive Security Experienced Penetration Tester (OSEP) -

by Offensive Security

Certificate ID: OSEP-26733

1/2019

Offensive Security Certified Professional (OSCP) -

by Offensive Security

Certificate ID: OS-101-036020

7/2023

OffSec Defense Analyst (OSDA) -

by Offensive Security

Certificate ID: OSDA-14780

8/2022

AWS Certified Cloud Practitioner -

by Amazon Web Services

Education


2012-2017

University of Athens (BSc)


Department of Informatics and Telecommunications


  • Specialisations in "Communications and Networking" and "Signal and Information Processing"
  • Certificate degree 8.93 / 10 : "Excellent"
  • 1.000€ Scholarship awarded by the Greek Post Offices (ELTA)
  • Notable software created as part of course assignments include: a C/C++ rainbow table-based password cracking tool (PassCrack), an ebay-like web marketplace written in Java (3bay), and a distributed network scanner system for Android devices (DistributedScanner)
7/2022

Antisyphon Trainings

(3 day training sessions) -

Online/Remote


"SOC Core Skills with John Strand"

"Active Defense and Cyber Deception with John Strand"

6/2019

Hack in Paris Trainings

(3 day training) -

Paris, FR


"Hacking IPv6 Networks"

5/2018

CanSecWest Dojos

(2 day training) -

Vancouver, CA


"Reversing for the JVM and Android"

9/2017

Systems and Networks Training Ltd

(2 day training) -

Limassol, CY


"Radio Frequency Fundamentals"

3/2016

Intracom Telecom & EESTEC LC Athens

(3 day training) -

Athens, GR


"Java Enterprise Edition Workshop"

Publications


CVE-2024-31903

"IBM Sterling B2B Integrator - Remote Code Execution

  • Security Advisory - TBC
  • Presented talk at DistrictCon Year 0 districtcon.org
N/A

"Kubernetes Attack Simulation: The Definitive Guide"

CVE-2021-22268
CVE-2021-22269
CVE-2021-22270
CVE-2021-22271

"Click Here For Free TV! - Chaining Bugs to Takeover Wind Vision Accounts"

CVE-2020-26062
CVE-2020-26063

Cisco IMC Server - Authorisation Bypass and Username Enumeration

N/A

Xiaomi Redmi 5 Plus - Second Space Password Bypass

Languages


5/2010

English

- Excellent / Near-Native Level

"Certificate of Profieciency in English" -

The University of Michigan

6/2010

German

- Intermediate Level

"Goethe-Zertifikat B2" -

Goethe Institut Athen

Greek

- Native Languange