Security Experts:

Connect with us

Hi, what are you looking for?


Application Security

Researchers Dive Into Equation Group Tool ‘DoubleFeature’

Security researchers at Check Point are publicly documenting the Equation Group APT’s DoubleFeature, a component of DanderSpritz post-exploitation framework.

Security researchers at Check Point are publicly documenting the Equation Group APT’s DoubleFeature, a component of DanderSpritz post-exploitation framework.

In a report published this week, the researchers provide a detailed analysis of DoubleFeature, the DanderSpritz component that was designed to generate “a log and report about the types of tools that could be deployed on the target.”

DanderSpritz and multiple additional tools were made public in 2017 by a group of hackers calling themselves the Shadow Brokers, after allegedly being stolen from the Equation Group – cyber-spies that were reportedly employed by the U.S. National Security Agency (NSA).

Although not as popular as Eternal Blue (ETBL), Eternal Romance (ETRO), and some other tools leaked by the Shadow Brokers, the DanderSpritz attack framework has been analyzed before, and researchers have also compared it to exploits used by Chinese hackers.

[ READ: Chinese Hackers Used NSA Tool a Year Before Shadow Brokers Leak ]

The documentation associated with many of the tools in the attack framework, the researchers point out, make reference to DoubleFeature, claiming that it represents the only manner in which their presence on a system could be verified.

Thus, DoubleFeature can be used to better understand DanderSpritz modules, and also “doubles as a diagnostic tool for victim machines carrying DanderSpritz — it’s an incident response team’s pipe dream,” Check Point said it its report.

DoubleFeature was designed to collect a large amount of data from the target system and to write the log information to a debug log file that is then encrypted using AES. The tool uses a rootkit and supports multiple obfuscation methods.

Furthermore the researchers noticed that the strings DoubleFeature needs are decrypted on demand and then re-encrypted. The unique feature, however, is the ability to query the Equation Group tools on a system and verify which ones are installed.

DoubleFeature monitors a series of modules, including UnitedRake (remote access tool), StraitBizarre (data exfiltration implant), KillSuit (a persistence and evasion plugin designed to run other modules), DiveBar (the KllSuit component responsible with persistence), FlewAvenue (IPv4 driver that provides network access to other tools), DuneMessiah (KillSuit instance), CritterFrenzy (another KillSuit instance), MistyVeal (validator implant), DiceDealer (parsing tool), and PeddleCheap (the first to run on a victim system, can “bootstrap a complete DanderSpritz installation”).

“For those of us with our heads deep enough up the cybercrime industry’s nether regions, many of the features described — rootkits, dedicated components to thoroughly vet victims, whole systems dedicated to logging the stages of post-exploitation — are, largely, abstract theory. The cybercrime industry’s DoubleFeature is typically an HTTP GET request containing &OS=win10, encrypted by some homebrew variant of RC4. The gap can really not be overstated,” Check Point concludes.

Related: Chinese Hackers Cloned Equation Group Exploit Years Before Shadow Brokers Leak

Related: Event Logs Manipulated With NSA Hacking Tool Recoverable

Written By

Ionut Arghire is an international correspondent for SecurityWeek.

Click to comment

Daily Briefing Newsletter

Subscribe to the SecurityWeek Email Briefing to stay informed on the latest threats, trends, and technology, along with insightful columns from industry experts.

Join this webinar to learn best practices that organizations can use to improve both their resilience to new threats and their response times to incidents.


Join this live webinar as we explore the potential security threats that can arise when third parties are granted access to a sensitive data or systems.


Expert Insights

Related Content

Application Security

Cycode, a startup that provides solutions for protecting software source code, emerged from stealth mode on Tuesday with $4.6 million in seed funding.

Data Protection

The CRYSTALS-Kyber public-key encryption and key encapsulation mechanism recommended by NIST for post-quantum cryptography has been broken using AI combined with side channel attacks.


Less than a week after announcing that it would suspended service indefinitely due to a conflict with an (at the time) unnamed security researcher...

Data Protection

The cryptopocalypse is the point at which quantum computing becomes powerful enough to use Shor’s algorithm to crack PKI encryption.


The changing nature of what we still generally call ransomware will continue through 2023, driven by three primary conditions.


WASHINGTON - Cyberattacks are the most serious threat facing the United States, even more so than terrorism, according to American defense experts. Almost half...

Application Security

PayPal is alerting roughly 35,000 individuals that their accounts have been targeted in a credential stuffing campaign.


No one combatting cybercrime knows everything, but everyone in the battle has some intelligence to contribute to the larger knowledge base.