STEALIEN

STEALIEN is a Seoul, South Korea-based cybersecurity firm founded in 2015, specializing in mobile application security through its AppSuit product line, a runtime application self-protection (RASP) and app-hardening solution for Android and mobile apps. AppSuit protects apps against reverse engineering, tampering, and dynamic instrumentation attacks by embedding defensive controls directly into the application binary rather than relying solely on network or device-level security.

The company’s core credibility argument is its team’s offensive pedigree: STEALIEN was built around competitive hacking-contest winners and finalists (CODEGATE, Hack In The Box CTF, DEFCON) and researchers with a track record of discovering vulnerabilities in major vendor products including Windows Kernel, Google Chrome, Adobe, and VMware. That attacker’s-eye-view is the company’s stated design philosophy for AppSuit — building defenses informed by how its own researchers would actually try to break an app.

AppSuit holds GS (Good Software) Certification Level 1, a government-accredited quality certification administered by Korea’s national IT testing authority, which is a genuine independent validation point for the South Korean market specifically, though it does not directly translate to an internationally recognized security-efficacy benchmark outside Korea. The company has also drawn investment interest from Korean financial-sector strategics, including Shinhan Futures Lab, KB Financial Group, IBK 1st Lab, and KB Innovation HUB, reflecting demand from Korea’s banking sector, where mobile-app tampering protection is a common regulatory and fraud-prevention requirement.

STEALIEN’s business is heavily concentrated in the South Korean market, where mobile-app RASP is a well-established compliance requirement for banking and fintech apps; its relevance outside that market, where it competes against global mobile app-security vendors like Guardsquare, Zimperium, and Promon, is less established given the company’s more limited international footprint and disclosure.