GandCrab Partners With NTCrypt for Code Obfuscation

GandCrab ransomware has evolved again, and the newest version features a partnership with NTCrypt to facilitate code obfuscation and frustrate security researchers.

As noted by McAfee, GandCrab’s authors deployed version 5 of the ransomware on Sept. 27. Since first appearing in January 2018, the code’s authors have released regular updates that both improved functionality and introduced new bugs.

As the McAfee report put it, the ransomware authors “are undoubtedly confident and have strong marketing skills, but flawless programming is not one of their strengths.” Still, public endorsement of FalloutEK and a new partnership with NTCrypt suggest that GandCrab is looking to claw its way into as many devices as possible with this new iteration.

What Does GandCrab’s Development Mean for Malware Security?

The makers of GandCrab aren’t afraid of notoriety; each new release comes with flashy announcements and promises of new partnerships. As a result, a members-only club of affiliates has developed around GandCrab, with more waiting in the wings to distribute the ransomware. GandCrab’s popularity has also led to partnerships with other criminal groups, which has helped the malware evolve from a simple infection vector to a more sophisticated ransomware-as-a-service.

Particularly concerning is GandCrab’s ability to attract other criminal groups. Its partnership with NTCrypt was established by way of competition: The crypter received $500 from the developers and free advertising in all of GandCrab advertisements. Beyond the obfuscation offered by NTCrypt services, this recruiting method provides a way for malware developers to avoid low-quality partners while diversifying their supply chain.

The ransomware uses multiple attack vectors to infect devices, encrypt files and demand cryptocurrency, including remote desktop connections, phishing emails, legitimate programs with hidden Trojans, exploit kits, PowerShell scripts and botnets such as Phorpiex.

How to Avoid the Pinch of GandCrab’s Code Obfuscation

Although the GandCrab developers are working hard to deliver regular updates, their lack of coding sophistication also introduces bugs that limit functionality or cause outright failure. For example, a compiling flaw in version 5 relies on a dynamic-link library (DLL) not available in Windows Vista or XP, meaning the malware will only work on machines running Windows 7 or later. The authors also claimed that their code doesn’t rely on existing CVE’s, but this is inaccurate — GandCrab uses both CVE-2018-8440 and CVE-2018-8120.

Despite its flaws, however, GandCrab remains a potent attack vector. To counter this type of malware security threat, security experts recommend establishing a security baseline, incorporating security best practices into all endpoint builds and ensuring a consistent “golden image” that adheres to your security policy. Security teams should also create and maintain a live inventory of all devices to help pinpoint malware infections, and develop “an aggressive and current patch management policy” to help mitigate the impact of existing vulnerabilities.

Source: McAfee

Douglas Bonderud

Freelance Writer

A freelance writer for three years, Doug Bonderud is a Western Canadian with expertise in the fields of technology and...