Dotrunpex

DotRunpeX is a rapidly evolving and highly stealthy .NET injector malware that has gained significant attention from both security analysts and threat actors. It employs the "Process Hollowing" method to distribute a wide variety of other malware strains, including AgentTesla, ArrowRAT, AsyncRat, AveMaria/WarzoneRAT, BitRAT, Formbook, LgoogLoader, Lokibot, NetWire, PrivateLoader, QuasarRAT, RecordBreaker – Raccoon Stealer, Redline, Remcos, Rhadamanthys, SnakeKeylogger, Vidar, and XWorm. The malware can infect systems through suspicious downloads, emails, or websites, often without the user's knowledge. Once inside, it can steal personal information, disrupt operations, or even hold data hostage for ransom. The malware is known for its ability to evade AV solutions using “procexp.sys” to close protected process handles. In addition to usual infection routes, DotRunpeX has been seen exploiting Google Ads, redirecting users searching for popular software like AnyDesk and LastPass to fake, malicious websites mimicking these software platforms. A unique case emerged where a DotRunpeX user targeted both regular victims and potential adversaries using a trojanized Redline builder with hidden DotRunpeX as 'extra'. The new version of DotRunpeX is also protected by a customized version of the KoiVM virtualizer and is highly configurable, with features such as disabling Anti-Malware services, Anti-VM, Anti-Sandbox, persistence settings, key for payload decryption, and UAC bypass methods. Cybersecurity researchers at Check Point have closely monitored and observed the real-world use and campaign-related infection paths of DotRunpeX malware. Their technical analysis revealed that DotRunpeX often follows the initial infection via distinct .NET loaders in phishing emails or disguised utility sites. The new version of DotRunpeX, compared to the old one, has more UAC Bypass techniques and uses simple XOR to decrypt the main payload to be injected. Furthermore, it abuses the procexp driver (Sysinternals) to kill protected processes, showing signs of being Russian based with the procexp driver name Иисус.sys translated as “jesus.sys”.