--- title: "Marios Grivas (@unfoundedomnis) | Hashnode" description: "#DEF. Read the latest articles by Marios Grivas on Hashnode." url: "https://hashnode.com/@unfoundedomnis" --- @unfoundedomnis # Marios Grivas @unfoundedomnis · Joined August 2025 #DEF ### [Reverse Engineering the Gov.gr Wallet: How a Hardcoded API Key Exposed Millions of Citizens](https://defprotocol.hashnode.dev/reverse-engineering-the-gov-gr-wallet-how-a-hardcoded-api-key-exposed-millions-of-citizens?utm_source=hashnode&utm_medium=feed) Discover how security by obscurity fails in mobile applications. Explore the gov.gr wallet case and learn best practices for API secrets management. 6 min read · [defprotocol.hashnode.dev](https://defprotocol.hashnode.dev/reverse-engineering-the-gov-gr-wallet-how-a-hardcoded-api-key-exposed-millions-of-citizens?utm_source=hashnode&utm_medium=feed) [May 26](https://hashnode.com/posts/reverse-engineering-the-gov-gr-wallet-how-a-hardcoded-api-key-exposed-millions-of-citizens/6a15b169da253d50d4bf1ef5) ### [The Ransomware Playbook: Anatomy of a Modern Attack](https://defprotocol.hashnode.dev/the-ransomware-playbook-anatomy-of-a-modern-attack?utm_source=hashnode&utm_medium=feed) Ransomware is no longer just about encrypting files and demanding payment. It has evolved into a structured, multi-stage operation that mirrors professional software development and organized business 4 min read · [defprotocol.hashnode.dev](https://defprotocol.hashnode.dev/the-ransomware-playbook-anatomy-of-a-modern-attack?utm_source=hashnode&utm_medium=feed) [Mar 3](https://hashnode.com/posts/the-ransomware-playbook-anatomy-of-a-modern-attack/69a7479c56428acc6f105181) ### [How Law Enforcement Tracks Cybercriminals. What Defenders Can Learn](https://defprotocol.hashnode.dev/how-law-enforcement-tracks-cybercriminals-what-defenders-can-learn?utm_source=hashnode&utm_medium=feed) When we think about the darkweb and cybercrime, it’s easy to imagine anonymity, hidden servers, and criminals that never get caught. Yet, history shows that even the most notorious groups, from AlphaBay’s operators to ransomware gangs like REvil and ... 2 min read · [defprotocol.hashnode.dev](https://defprotocol.hashnode.dev/how-law-enforcement-tracks-cybercriminals-what-defenders-can-learn?utm_source=hashnode&utm_medium=feed) [Sep 15, 2025](https://hashnode.com/posts/how-law-enforcement-tracks-cybercriminals-what-defenders-can-learn/68c8a62d4d114d89c85e1dc6) ### [Building a Cybercrime Timeline: Why History Matters in Threat Intelligence](https://defprotocol.hashnode.dev/building-a-cybercrime-timeline-why-history-matters-in-threat-intelligence?utm_source=hashnode&utm_medium=feed) Cybersecurity news often feels like chaos, one breach after another, new ransomware names every week, shifting tactics, and endless headlines. But behind the chaos, there’s a timeline. And building that timeline is one of the most underrated skills i... 2 min read · [defprotocol.hashnode.dev](https://defprotocol.hashnode.dev/building-a-cybercrime-timeline-why-history-matters-in-threat-intelligence?utm_source=hashnode&utm_medium=feed) [Sep 8, 2025](https://hashnode.com/posts/building-a-cybercrime-timeline-why-history-matters-in-threat-intelligence/68be8e7e28d1e5e52e47ef65) ### [Learning from Lazarus Group: Defensive Takeaways from a Notorious APT](https://defprotocol.hashnode.dev/learning-from-lazarus-group-defensive-takeaways-from-a-notorious-apt?utm_source=hashnode&utm_medium=feed) When we talk about Advanced Persistent Threats (APTs), few names resonate as much as Lazarus Group. Linked to North Korea, this threat actor has been active for over a decade, from the Sony Pictures hack (2014) to the WannaCry ransomware outbreak (20... 3 min read · [defprotocol.hashnode.dev](https://defprotocol.hashnode.dev/learning-from-lazarus-group-defensive-takeaways-from-a-notorious-apt?utm_source=hashnode&utm_medium=feed) [Sep 3, 2025](https://hashnode.com/posts/learning-from-lazarus-group-defensive-takeaways-from-a-notorious-apt/68b8a363f14f16751b6a8c2f)