archive

Cybercriminals are using legitimate software installer frameworks like Inno Setup to distribute malware, taking advantage of its trusted appearance and scripting capabilities. A recent campaign demonstrated how a malicious Inno Setup installer can deliver information-stealing malware, such as RedLine Stealer, through a multi-stage infection process. This process includes evasion techniques like detecting debuggers and sandbox environments, using XOR encryption to obscure strings, and conducting WMI queries to identify malware analysis tools. The installer retrieves a payload from a command-and-control server via a TinyURL link and creates a scheduled task for persistence. The payload employs DLL sideloading to load HijackLoader, which ultimately injects RedLine Stealer into a legitimate process to steal sensitive information. RedLine Stealer uses obfuscation techniques and disables security features in browsers to avoid detection. The Splunk Threat Research Team has developed detection methods focusing on indicators such as unsigned DLL sideloading and suspicious browser behaviors. Indicators of Compromise (IOC): - Malicious Inno Setup Loader Hash 1: 0d5311014c66423261d1069fda108dab33673bd68d697e22adb096db05d851b7 - Malicious Inno Setup Loader Hash 2: 0ee63776197a80de42e164314cea55453aa24d8eabca0b481f778eba7215c160 - Malicious Inno Setup Loader Hash 3: 12876f134bde914fe87b7abb8e6b0727b2ffe9e9334797b7dcbaa1c1ac612ed6 - Malicious Inno Setup Loader Hash 4: 8f55ad8c8dec23576097595d2789c9d53c92a6575e5e53bfbc51699d52d0d30a