Skip to content
View JustaNotion's full-sized avatar

Block or report JustaNotion

Block user

Prevent this user from interacting with your repositories and sending you notifications. Learn more about blocking users.

You must be logged in to block users.

Maximum 250 characters. Please don’t include any personal information such as legal names or email addresses. Markdown is supported. This note will only be visible to you.
Report abuse

Contact GitHub support about this user’s behavior. Learn more about reporting abuse.

Report abuse
JustaNotion/README.md

Ian Lemus

Cybersecurity and cloud, focused on identity and detection. I build small working systems and document the decisions behind them — especially the permission boundaries most tutorials skip past.

Currently targeting IAM and SOC analyst work — based in Dallas–Fort Worth, open to relocating anywhere in the US!


Projects

Entra-ID-Identity-Lab — Joiner-mover-leaver run in a self-built Microsoft Entra ID tenant, the cloud counterpart to the AD lab above. The write-up covers what soft-delete actually revokes (the object comes back, but the entitlement was gone the whole time), standing privilege as the concrete case for PIM, and the audit-log evidence behind each phase.

Active-Directory-Identity-Lab — Two-VM Active Directory domain (Windows Server 2025 → Windows 11 client) built to run a full joiner-mover-leaver cycle. OU and security group design scoped to job function, with the mover step removing the old group rather than stacking a new one — the write-up covers privilege creep, the Security log events proving each phase (4720, 4729, 4725), and the APIPA misconfiguration I diagnosed along the way.

Splunk-Brute-Force-Detection — Brute-force detection in Splunk Enterprise. SPL search that extracts usernames and source IPs from Linux auth logs and ranks attackers by attempt volume and distinct accounts targeted. The write-up covers how I caught a duplicate-ingestion error by cross-checking Splunk against an independent Python parser.

SSH-Log-Analyzer — Python script that parses SSH authentication logs, counts failed attempts per source IP, and flags addresses crossing a threshold. The independent check that validated the Splunk work above.

Failed-Login_Parser — Serverless AWS pipeline (S3 → Lambda → DynamoDB) that parses SSH logs for brute-force attempts. Built around least-privilege IAM — the write-up includes the scoped execution policy, the resource-based policy, and the AccessDenied errors I worked through getting there.


Background

Four years in restaurant operations, three of them in leadership, most recently fifteen months owning account provisioning and deprovisioning across four systems. That work also included physical access controls and responding to audit findings — which is where the interest in identity started.


Certifications

  • CompTIA Security+ — 2026
  • AWS Certified Cloud Practitioner (CLF-C02) — 2026

Currently learning

KQL, Microsoft Sentinel and detection engineering. AWS IAM at depth.


LinkedIn

Pinned Loading

  1. Entra-ID-Identity-Lab Entra-ID-Identity-Lab Public

    Cloud identity lab in a self-built Microsoft Entra ID tenant — lifecycle, privileged roles, audit evidence, and deletion/recovery testing.

  2. Active-Directory-Identity-Lab Active-Directory-Identity-Lab Public

    Small scale lab setup using two different VMs meant to demonstrate knowledge and practice of the joiner-mover-leaver cycle

  3. Splunk-Brute-Force-Detection Splunk-Brute-Force-Detection Public

    A project in Splunk meant to detect, highlight and provide a list of Source IPs (src_ip), the failed attempts and also the unique username associated.

  4. SSH-Log-Analyzer SSH-Log-Analyzer Public

    Python tool that parses SSH auth logs and flags brute-force source IPs by failed-attempt threshold.

    Python