Cybersecurity researchers have offered a detailed glimpse into a system called DoubleFeature that's dedicated to logging the different stages of post-exploitation stemming from the deployment of DanderSpritz, a full-featured malware framework used by the Equation Group.
DanderSpritz came to light on April 14, 2017, when a hacking group known as the Shadow Brokers leaked the exploit tool, among others, under a dispatch titled "Lost in Translation." Also included in the leaks was EternalBlue, a cyberattack exploit developed by the U.S. National Security Agency (NSA) that enabled threat actors to carry out the NotPetya ransomware attack on unpatched Windows computers.
The tool is a modular, stealthy, and fully functional framework that relies on dozens of plugins for post-exploitation activities on Windows and Linux hosts. DoubleFeature is one among them, which functions as a "diagnostic tool for victim machines carrying DanderSpritz," researchers from Check Point said in a new report published Monday.
"DoubleFeature could be used as a sort of Rosetta Stone for better understanding DanderSpritz modules, and systems compromised by them," the Israeli cybersecurity firm added. "It's an incident response team's pipe dream."
Designed to maintain a log of the types of tools that could be deployed on a target machine, DoubleFeature is a Python-based dashboard that also doubles up as a reporting utility to exfiltrate the logging information from the infected machine to an attacker-controlled server. The output is interpreted using a specialized executable named "DoubleFeatureReader.exe."
Some of the plugins monitored by DoubleFeature include remote access tools called UnitedRake (aka EquationDrug) and PeddleCheap, a stealthy data exfiltration backdoor dubbed StraitBizarre, an espionage platform called KillSuit (aka GrayFish), a persistence toolset named DiveBar, a covert network access driver called FlewAvenue, and a validator implant named MistyVeal that verifies if the compromised system is indeed an authentic victim machine and not a research environment.
"Sometimes, the world of high-tier APT tools and the world of ordinary malware can seem like two parallel universes," the researchers said. "Nation-state actors tend to [maintain] clandestine, gigantic codebases, sporting a huge gamut of features that have been cultivated over decades due to practical need. It turns out we too are still slowly chewing on the 4-year-old leak that revealed DanderSpritz to us, and gaining new insights."