The threat actor referred to as Cloud Atlas has been linked to a set of spear-phishing attacks on Russian enterprises.
Targets included a Russian agro-industrial enterprise and a state-owned research company, according to a report from F.A.C.C.T., a standalone cybersecurity company formed after Group-IB’s formal exit from Russia earlier this year.
In December 2022, Check Point and Positive Technologies detailed multi-stage attack sequences that led to the deployment of a PowerShell-based backdoor referred to as PowerShower as well as DLL payloads capable of communicating with an actor-controlled server.
The starting point is a phishing message bearing a lure document that exploits CVE-2017-11882, a six-year-old memory corruption flaw in Microsoft Office’s Equation Editor, to kick-start the execution of malicious payloads, a technique Cloud Atlas has employed as early as October 2018.
The malicious HTML application subsequently launches Visual Basic Script (VBS) files that are ultimately responsible for retrieving and executing an unknown VBS code from a remote server.
“The group’s toolkit has not changed for years—they try to hide their malware from researchers by using one-time payload requests and validating them. The group avoids network and file attack detection tools by using legitimate cloud storage and well-documented software features, in particular in Microsoft Office.”
The development comes as the company said that at least 20 organizations located in Russia have been compromised using Decoy Dog, a modified version of Pupy RAT, attributing it to an advanced persistent threat actor it calls Hellhounds.
“After materials on the first version of Decoy Dog were published, the malware authors went to a lot of effort to hamper its detection and analysis both in traffic and in the file system,” security researchers Stanislav Pyzhov and Aleksandr Grigorian said.
Source: https://thehackernews.com/
