Reverse Engineering Tutorial Explores Hybrid Analysis of Linux x86-64 Crackme Using Ghidra and GDB
A comprehensive tutorial series introduces readers to hybrid reverse engineering of a Linux crackme titled Getting started keygen authored by Mazzotti. The binary presents itself as an introductory challenge yet contains realistic C++ constructs including optimized stack frames, mangled names, and opaque data structures.
The first article begins with basic triage using the file command, revealing a 64-bit PIE ELF dynamically linked against libc and libstdc++. Strings extraction surfaces user prompts such as "Enter a string of characters (no spaces)" and responses including "Bro, what are you trying to do?" and "OMG! You did it! :3".
Static analysis proceeds in Ghidra, where the analyst locates the true entry point at address 0x1340, demangles C++ symbols, and identifies imported std::string operations. The tutorial contrasts non-optimized and optimized (-O1) compilation outputs to explain why the frame pointer is omitted and why Ghidra initially mislabels stack variables such as local_58 and local_7c.
Dynamic validation occurs inside GDB with careful calculation of ASLR-adjusted addresses. Breakpoints placed before and after input allow verification of stack layout, growth and shrinkage behavior, and the actual four-byte size of certain locals that the decompiler had sized incorrectly.
The series stresses iterative refinement: decompiler output supplies hypotheses, the debugger confirms or refutes them, and corrected information is returned to Ghidra to improve type recovery. Subsequent installments will apply mutation testing and reconstruct the hidden validation algorithm in Python.
Related articles
DDoS-Guard Reports Record 540,000 L7 Attacks in June 2026 Amid Botnet Fragmentation
DDoS-Guard recorded a sharp 70% increase in L7 attacks during Q2 2026, with June alone seeing 540,000 incidents. Global volumetric attacks doubled compared to all of 2025, including peaks of 1.64 Tbps and 1.58 Tbps. Law enforcement dismantled four major IoT botnets—Aisuru, KimWolf, JackSkid and Mossad—in March, yet long-duration L7 campaigns surged 380%. Attackers shifted focus to application-layer exhaustion using browser automation and AI agents while targeting HR platforms and news sites. Europol’s Operation PowerOFF led to 75,000 warnings and 53 domain takedowns across 21 countries. Experts attribute the June spike to attacks aimed at protection providers themselves rather than single domains.
Spyware-Laden Modified iOS Apps Distributed via Russian Telegram Channel, Kaspersky Discovers
Kaspersky researchers have identified modified versions of popular iOS applications that are being distributed through a Russian-language Telegram channel and contain a malicious spying module. The infected apps include a marketplace platform for selling goods, a photo editor, and a video viewing service, all offered as ad-free versions with extra free features. Attackers embed the spyware directly into legitimate IPA files, while some clean apps simply promote the same channel to funnel users toward the malicious downloads. Installation requires users to obtain a developer certificate and sign the app using tools such as eSign or Scarlet, or to sideload via a computer or jailbroken device, completely bypassing the App Store. Once launched, the malware collects device name, battery level, regional settings, memory information, jailbreak status, geolocation, carrier code, and screenshots before sending the data to the attackers, although it stops when the app is closed. Kaspersky advises users to obtain applications only from official stores or verified developer websites rather than random Telegram sources.
DarkSword Exploit Kit Expands to 180 Sites Targeting iPhone Users with Zero-Click Chain
The DarkSword exploit kit has scaled its infrastructure to 180 web properties hosted on 27 servers, enabling zero-click compromise of iPhones running vulnerable iOS versions. Attackers deploy fake pages impersonating Apple, AWS, and other popular services to trigger a six-vulnerability exploit chain that achieves remote code execution, sandbox escape, and privilege escalation on iOS 18.4 through 18.7. Once the device is compromised, GHOSTBLADE components extract data from the Keychain, iCloud files, Wi-Fi passwords, and other stored content before exfiltrating it to attacker-controlled panels. The malware deletes crash reports and forensic logs to hinder analysis and does not establish traditional persistence, limiting the window of data theft to a single visit. Infrastructure rotates rapidly, with five of seven administrative panels observed on July 30, 2026, having appeared only a week earlier, indicating frequent domain and host replacement to evade blocking.
Octagon Android RAT Poses as Bahrain Emergency Alert App to Steal Credentials and Establish Persistent Surveillance
A remote access trojan named Octagon targets Android devices by masquerading as the official emergency alerts application from Bahrain. The infection begins when victims download the BH-Alert.apk file from phishing websites. The malware guides users through seven steps to grant dangerous permissions while using encrypted code hidden inside a font file extension to evade static analysis. It installs a secondary component called OctagonPanel and deploys mutual-monitoring surveillance services that restart each other if terminated. Additional persistence is achieved through boot receivers, a fake Android account, and scheduled synchronization tasks every 30 minutes. The trojan abuses the Accessibility Service to record unlock patterns, PINs, and passwords while also harvesting SMS messages, contacts, call logs, and screenshots. A criminal-controlled VPN allows interception and redirection of victim traffic.