Last week, Unit 42 released a blog on a newly named threat group called DarkHydrus that we observed targeting government entities in the Middle East. The attack that we discussed in our previous publication involved spear-phishing to deliver a PowerShell payload we call RogueRobin; however, we are aware of DarkHydrus carrying out a credential harvesting attack in June 2018. It also appears that this an ongoing campaign, as we have evidence of previous credential harvesting attempts using the same infrastructure dating back to the Fall of 2017. The credential harvesting attacks used spear-phishing emails that contained malicious Microsoft Office documents that leveraged the “attachedTemplate” technique to load a template from a remote server. When attempting to load this remote template, Microsoft Office will display an authentication dialog box to ask the user to provide login credentials. When entered, these credentials are then sent to the C2 server, which allows DarkHydrus to collect the user account credentials. Based on Unit 42’s analysis, DarkHydrus used the open-source Phishery tool to create two of the known Word documents used in these credential harvesting attacks. As discussed in our previous blog, this further strengthens DarkHydrus’ use of the open source for their attack tools. A phishing attack to steal credentials like this is not new: US-CERT warned of the same technique by a different threat group in 2017. Based on this, we can reasonably presume this group will continue to carry out attacks against these kinds of targets in the Middle East in the near-future