CTF Writeup: Red Stealer

Analyze a suspicious executable using VirusTotal and MalwareBazaar to extract IOCs, identify C2 infrastructure, MITRE ATT&CK techniques, and privilege escalation mechanisms. Introduction Another Threat Intel focused lab for today. The red stealer lab available through Cyber Defenders. You are part of the Threat Intelligence team in the SOC (Security Operations Center). An executable file has been discovered on a colleague’s computer, and it’s suspected to be linked to a Command and Control (C2) server, indicating a potential malware infection. Your task is to investigate this executable by analyzing its hash. The goal is to gather and analyze data beneficial to other SOC members, including the Incident Response team, to respond to this suspicious behavior efficiently. ...

January 14, 2026 · 7 min · 1409 words · Ligniform

CTF Writeup: PhishStrike

Analyze email headers and threat intelligence to identify phishing indicators, malware persistence, and C2 channels, extracting actionable IOCs. Introduction It’s no secret that I’m no stranger to phishing emails. A lot of the grunt-y SOC work I do is analyzing potential phishing emails. Some people consider it boring or repetitive and while I understand this sentiment I don’t entirely agree with it. The process can be pretty fun if you see new phishing lures and compile IOCs. ...

January 7, 2026 · 16 min · 3297 words · Ligniform

CTF Writeup: FakeGPT

Analyze a malicious Chrome extension’s code and behavior to identify data theft mechanisms, covert exfiltration via <img> tags, and anti-analysis techniques. Introduction It’s the last day of 2025. No better way to celebrate than to publish a write-up of a year old lab. Specifically the FakeGPT Lab over on CyberDefenders. As we can see from the introductionary text we will be analyzing a malicious chrome extension. We get a quick peek into how data is exfiltrated via <img> tags, and there’s a hint into some evasion/anti-analysis techniques we’ll be looking into. ...

December 31, 2025 · 10 min · 2032 words · Ligniform

CTF Writeup: PoisonedCredentials Lab

Analyze network traffic for LLMNR/NBT-NS poisoning attacks using Wireshark to identify the rogue machine, compromised accounts, and affected systems. When I first saw this lad and the description I was a little confused what LLMNR and NBT-NS poisoning attackers were. I’m familiar with poisoning attacks like ARP and DNS, but the LLMNR and NBT-NS protocols didn’t ring a bell for me. A lot of cybersecurity is research and understanding concepts, so I was happy to jump into this lab from CyberDefenders and learn something new. ...

November 15, 2025 · 6 min · 1156 words · Ligniform

CTF Writeup: L'Espion Lab

Investigate an insider threat by analyzing GitHub repositories for exposed credentials, using OSINT tools to correlate online accounts, and performing image analysis to identify locations. Unlike in any of my previous write-ups, this time I completed the entire lab before sitting down to write this. I think it’s important to keep the flow of how I answered all the questions, including any mistakes or rabbit-holes. With an OSINT focused room like this one it’s very easy to find false-positives and go on a deep dive on profiles that aren’t related at all to the target. ...

November 5, 2025 · 12 min · 2508 words · Ligniform