Alexandre Lestruhaut

Cybersecurity Engineer

Security expert, automation maniac, team player, knowledge thirsty, AI augmented

Experience

Cybersecurity engineer

Capgemini2022-08-172024-10-31

Documentation, new client build, automation

  • Documentation migration from confluence to a git based system
  • Gitlab CI/CD developement to automate documentation compliance checks (PDIS, a french security framework), static website deployment using astroJS
  • New client build for a major bank : Asset identification, scenario definition, rules creation and finetuning
  • L2 mentoring regarding AQL (Qradar query langage), investigation reasoning
  • Scripting to automate MRO reporting using python (libs : jupyter, pandas, openpyxl)
  • Gitlab CI/CD developement to maintain SIGMA rules database, deploying a static website for easy consultation, automatic deployment to Qradar SIEM

L2 cybersecurity analyst

Capgemini2021-01-122022-08-17

Security incidents analysis, handling escalations, mentoring L1 analysts, rule tuning, reporting

  • Dedicated to a challenging client
  • On call
  • Escalated incidents analysis with Qradar and Splunk
  • Process redaction to use the various specific client tools
  • Fine tuning Qradar detection rules
  • Developed scripts to automate reports generation
  • Communication with the client about the state of security of a permieter
  • Formation of L1 analysts

L1 cybersecurity analyst

Capgemini2020-05-012021-01-12

Security incidents analysis

  • Three-shift schedule
  • Incidents analysis, investigation in SIEM (Qradar, Splunk, Kibana), ticket redaction in Jira
  • Designed and implemented an automation tool using greasemonkey and Typescript (react, express)
  • Developed python scripts to automate document generation for a specific client
  • Developed a powershell script to automate file exchange with an air-gaped environment

Projects

Mary Poppins

2021-09-012021-12-31

Security incidents automatic completion through SIEM API requests

  • Used by the whole L1 team
  • Saves around 50 minutes per shift
  • Inject information into Jira through the greasemonkey browser extension
  • Automate SIEM requests using Qradar API
  • Uses Twig template engine
  • Web ui for template management using React
  • Express in the backend
  • Checks the ticket compliance (many specific client requests)

Automatic Qradar rule deployment through CI/CD

2022-08-012023-02-01

Convert sigma rules to Qradar XML format and deploy them through SSH

  • Reverse engineered the Qradar rule XML undocumented format
  • Convert SIGMA to AQL using pysigma library
  • Optimize generated AQL by cutting and ordering the request depending on the performance
  • Deploy the generated rule through SSH (API does not support it)

Documentation migration to git

2023-05-012023-08-01

Migrate the team documentation from confluence to a git based system with CI/CD and static site generation

  • Enables automatic deployment for new clients (inherit a generalist documentation so it can be supercharged with client specific informations)
  • Reduced maintenance costs
  • Perform compliance checks and reporting through Gitlab CI/CD
  • Static site generation for easy consultation using astroJS

Homelab

2024-09-01Present

Setup of a homelab to learn new skills

  • Virtualization with Proxmox
  • Containerization with Docker compose
  • Routing with Traefik and fail2ban, OWASP waf, geoblocking plugins
  • Configuration management with Ansible
  • OPNsense firewall deployment, configuration and maintenance
  • Configure crowsec to block suspcious IPs
  • Setup wireguard VPN
  • Deploy Wazuh for security monitoring
  • WIP : Setup an AI assistant using langchain, with RAG trhough a Qdrant vector database and a Neo4j graph database. MCP setup for websearch. A router local agent will decide if a local agent can handle the requests or if an groq agent is needed
  • Upcoming : deploy and configure EFK stack, suricata

NixOS

2025-11-01Present

Currently in a honeymoon with this OS

  • Experimenting in a VM

Education

Institut Toulousain d'Ostéopathie

MasterOsteopathy

2009-09-012015-12-01