From July to September, we observed the DarkGate campaign (detected by Trend Micro as TrojanSpy.AutoIt.DARKGATE.AA) abusing instant messaging platforms to deliver a VBA loader script to victims. This script downloaded and executed a second-stage payload consisting of a AutoIT scripting containing the DarkGate malware code. It’s unclear how the originating accounts of the instant messaging applications were compromised, however is hypothesized to be either through leaked credentials available through underground forums or the previous compromise of the parent organization.
First publicly reported in 2018, DarkGate is a Windows-based malware with a wide-range of capabilities including credential stealing and remote access to victim endpoints. Until recently, it was only seen being delivered through traditional email malspam campaigns. In late August 2023, however, researchers at Trusec found evidence of a campaign using external Teams messages to deliver the DarkGate Loader.