We came across a new version of a cryptocurrency-mining RETADUP worm (detected by Trend Micro as WORM_RETADUP.G) through feedback from our managed detection and response-related monitoring. This new variant is coded in AutoHotKey, an open-source scripting language used in Windows for creating hotkeys (i.e., keyboard shortcuts, macros, software automation). AutoHotKey is relatively similar to the script automation utility AutoIt, from which RETADUP’s earlier variants were based on and used for both cybercrime and cyberespionage.

We identified this threat via an endpoint — from an organization in the public sector — that had related malware artifacts (as RETADUP was promptly blocked). Further analyzing and correlating them based on their C&C protocol and our own RETADUP detections, we found that they were similar to other samples we sourced. These indicate that, at least for now, RETADUP’s operators — despite their history in deploying their malware in targeted attacks — are focusing on cybercriminal cryptocurrency mining.