A cyberattack campaign by the advanced persistent threat group Stealth Falcon targeted a prominent Turkish defense company using a zero-day vulnerability identified as CVE-2025-33053. This vulnerability allowed attackers to manipulate the working directory of legitimate Windows tools to execute malware from their WebDAV servers. The attack was initiated through a spear-phishing email containing a malicious .url file that directed the system to a legitimate Internet Explorer utility, which was then exploited to execute malicious files. The attackers employed process hollowing to bypass traditional defenses.
Stealth Falcon, also known as FruityArmor, has been conducting cyber espionage since at least 2012, targeting government and defense sectors in Turkey, Qatar, Egypt, and Yemen. The attack involved a multi-stage infection chain leading to the deployment of "Horus Agent," a custom implant designed for advanced reconnaissance and equipped with anti-analysis techniques. Researchers identified additional custom tools used by Stealth Falcon, including a DC Credential Dumper and a custom keylogger. The group utilizes repurposed legitimate domains to blend their infrastructure with legitimate traffic, complicating detection efforts.