Felix ‘FX’ Lindner, Head of Recurity Labs


FX is the technical and research lead of Recurity Labs over 25 years of experience in the computer industry, almost all of them in consulting for large enterprise customers and possesses a vast knowledge of computer sciences, telecommunications and software development. His background includes managing and participating in a variety of projects with a special emphasis on security planning, implementation, operation and testing, using advanced methods in diverse technical environments.

FX is well known in the computer security community and has presented his and Phenoelit’s security research on Black Hat Briefings, CanSecWest, PacSec, DEFCON, Chaos Communication Congress, MEITSEC and numerous other events. His research includes Cisco IOS, HP printers, SAP and RIM BlackBerry. Felix holds a title as State-Certified Technical Assistant for Informatics and Information Technology as well as Certified Information Systems Security Professional.

Operations Team


Nico, Florian and Jan represent the Operations team at Recurity Labs and serve as main point of contact. Apart from their individual email addresses, the Operations team can be reached via operations@recurity-labs.com.

Nico Lindner, CEO


During his studies of applied computer science, Nico started his professional career as an event technician and manager in the Audio/Video (AV) field. He quickly excelled and was promoted to deputy chief engineer in a highly respected venue. He continued to fulfil this position until 2010, specializing in the management of events, while never losing grip of the ever-changing technical playground.

After gathering over a decade of experience in this line of work, Nico was recruited to support the corporate management at Recurity Labs. Over the course of the years, he has taken on a major proportion of the management side at Recurity Labs and currently serves as its CEO.

Florian Grunert, Operations


Florian joined Recurity Labs in 2013 and serves as key account and project manager. Since then he supports the team in countless projects, being responsible for the direction, coordination, implementation, execution, control and completion of our projects, while remaining aligned with strategy, commitments and goals of the organization.

Jan Grotelüschen, Operations


Jan is a graduated electronics engineer and joined Recurity Labs in mid 2017. He completes the operations team at Recurity Labs contributing two decades of project management experience.

Consulting Team

Michael Günther, Senior Security Consultant


As a Senior Security Consultant, with the experience of countless projects for not only large financial industry and telecommunication customers, Michael complements the Recurity Labs team with his skills ranging from Threat Modeling of complex environments, analysis of process and procedure frameworks, to the execution of in-depth technical analyses, such as protocol reverse engineering and application penetration testing.

Michael presented at DEFCON, Chaos Communication Congress, Chaos Communication Camp and Toorcon.

Joern Schneeweisz, Vulnerability Researcher


Joern joined Recurity Labs in 2007 right after he abandoned his studies of IT Security at Ruhr-University Bochum. His main focus areas are Source Code assessments and white-box tests, but also Reverse Engineering and working on the Design Level is included in his daily responsibilities.

His private vulnerability research focuses on Ruby on Rails applications in this context he published a Phrack article as well as numerous advisories for different Ruby on Rails applications and for the framework itself.

Joern has been presenting on various conferences including Ekoparty, Hack in the Box, ZeroNights, Hacktivity, t2, and OWASP Appsec EU/US.

Carsten Wentzlow, Security Consultant


Carsten supported Recurity Labs as a freelancer in fields of gray box penetration testing and source code audits over several years. After his studies of computer science at the Freie Universität (FU) Berlin and gathering experience in consulting large companies, he joined the team in October 2009, providing skills in source code auditing and architectural review, ranging from embedded devices to globally deployed solutions.

Jennifer Gehrke, Security Consultant


After her diploma in Mathematics and Computer Science at the Humboldt University of Berlin, Jennifer joined the Recurity Labs team in 2013. In addition to the company’s core activities of source code audits and dynamic security testing of solutions of various scales, she provides support in different security related design questions. Through her background in mathematics and theoretical computer science, she provides consultation on design related topics from threat modelling to the review of complex cryptographic solutions or custom security protocols.

Andreas Lindh, Security Consultant


Andreas Lindh is a security consultant and researcher with over a decade of applied security experience and a wide variety of skills, spanning areas such as Web application security, network intrusion detection and Malware analysis. Prior to joining Recurity Labs in 2015, Andreas worked for international telecoms and financial institutions and a global automotive manufacturer, as well as for a managed security services provider. At Recurity Labs, his main focus are source code audits, and application and device security assessments. Andreas has presented his work at leading industry conferences such as Black Hat USA and Troopers, and is currently a member of the Black Hat review board.

Sascha Schirra, Security Consultant


Sascha joined the Recurity Labs consulting team in Juli 2018 after supporting Recurity Labs as a freelancer for several years. His focus areas are source code audits, mobile security, embedded systems and reverse engineering. Sascha holds a title as state-certified technician for Informatics. Prior to joining Recurity Labs, he has worked as Software Developer and IT security specialist for a German state authority.

Stefan Seefeldt, Junior Security Consultant


Stefan Seefeldt is a Junior IT Security Consultant at Recurity Labs since March 2018, focusing on source code audits and penetration testing. Stefan graduated with an M.S. in Computer Science and wrote his Master’s thesis on advanced exploitation techniques.

Contracting Consultants

In addition to its own team, Recurity Labs works with a body of contracting consultants. This group consists of hand-picked professionals with exceptional skills in their specific area. Close cooperation with contracting consultants is one of the core operating concepts at Recurity Labs. Specialists often do not fit into permanent employment, since it steals the self-development time they need, want and require. On the other hand, permanent positions cannot constantly provide challenging missions. Recurity Labs strives to balance the two, achieving a high acceptance by the contracting consultants and full satisfaction of the customer, who gets extra specialist knowledge with the quality of Recurity Labs’ work.