iOS Elegantbouncer: When You Can't Get Samples but Still Need to Catch Threats

Summary

The Genesis: When Signatures Aren’t Enough 🔗In the world of mobile security research, there’s a recurring frustration that keeps many of us up at night: the most sophisticated exploits - the ones that really matter - are rarely shared. When Citizen Lab and Google TAG discover NSO Group’s latest 0-click exploits targeting journalists and activists, we get brilliant technical writeups, CVE numbers, and patches. What we don’t get? The actual samples. This isn’t a criticism - there are excellent reasons for limiting access to weaponized exploits. But it creates a fundamental problem: How do you protect against threats you’ve never seen? Traditional detection approaches like YARA rules, IOC matching, and signature-based systems fall apart when: You don’t have the actual malicious samples to create signatures from The attackers use polymorphic techniques that change file hashes The exploit leverages legitimate file format features in unexpected ways You need to detect future variants of the same technique This is where ELEGANTBOUNCER was born - not from having access to elite exploit collections, but from the opposite: having to detect threats based solely on technical descriptions, vulnerability reports, and proof-of-concept recreations. The Philosophy: Structure Over Signatures 🔗ELEGANTBOUNCER takes a fundamentally different approach to threat detection. Instead of looking for specific byte patterns or known-bad indicators, it analyzes the structural properties of files that make exploits possible. graph TD A[File Input] --> B{File Type Detection} B -->|PDF/GIF| C[JBIG2 Parser] B -->|WebP| D[VP8L Parser] B -->|TTF/OTF| E[TrueType Parser] B -->|DNG/TIFF| F[DNG Parser] C --> G[FORCEDENTRY Detection] D --> H[BLASTPASS Detection] E --> I[TRIANGULATION Detection] F --> J[CVE-2025-43300 Detection] G --> K{Structural Analysis} H --> K I --> K J --> K K -->|Malicious Structure| L[🚨 Threat Detected] K -->|Normal Structure| M[✓ File Clean] style L fill:#ff4444,stroke:#ff0000,stro...