Malware is constantly finding new ways to avoid detection. This doesn’t mean that some will never be detected, but it does allow adversaries to increase the period of time between initial release and detection. Flying under the radar for just a few days is enough to infect sufficient machines to earn a decent amount of revenue for an attack. Cisco Talos recently discovered a new campaign delivering the HawkEye Reborn keylogger and other malware that proves attackers are constantly creating new ways to avoid antivirus detection. In this campaign, the attackers built a complex loader to ensure antivirus systems to not detect the payload malware. Among these features is the infamous “Heaven’s Gate” technique — a trick that allows 32-bit malware running on 64-bit systems to hide API calls by switching to a 64-bit environment. In this blog, we will show how to analyze this loader quickly, and provide an overview of how these attackers deliver the well-known HawkEye Reborn malware. During our analysis, we also discovered several notable malware families, including Remcos and various cryptocurrency mining trojans, leveraging the same loader in an attempt to evade detection and impede analysis.



Talos Group

Talos Security Intelligence & Research Group