A cybercrime group known as Vice Society has been linked to multiple ransomware strains in its malicious campaigns aimed at the education, government, and retail sectors.
The Microsoft Security Threat Intelligence team, which is tracking the threat cluster under the moniker DEV-0832, said the group avoids deploying ransomware in some cases and rather likely carries out extortion using exfiltrated stolen data.
"Shifting ransomware payloads over time from BlackCat, Quantum Locker, and Zeppelin, DEV-0832's latest payload is a Zeppelin variant that includes Vice Society-specific file extensions, such as .v-s0ciety, .v-society, and, most recently, .locked," the tech giant's cybersecurity division said.
Vice Society, active since June 2021, has been steadily observed encrypting and exfiltrating victim data, and threatening companies with exposure of siphoned information to pressure them into paying a ransom.
"Unlike other RaaS (Ransomware-as-a-Service) double extortion groups, Vice Society focuses on getting into the victim system to deploy ransomware binaries sold on Dark web forums," cybersecurity company SEKOIA said in an analysis of the group in July 2022.
The financially motivated threat actor is known to rely on exploits for publicly disclosed vulnerabilities in internet-facing applications for initial access, while also using PowerShell scripts, repurposed legitimate tools, and commodity backdoors such as SystemBC prior to deploying the ransomware.
Vice Society actors have also been spotted leveraging Cobalt Strike for lateral movement, in addition to creating scheduled tasks for persistence and abusing vulnerabilities in Windows Print Spooler (aka PrintNightmare) and Common Log File System (CVE-2022-24521) to escalate privileges.
"Vice Society actors attempt to evade detection through masquerading their malware and tools as legitimate files, using process injection, and likely use evasion techniques to defeat automated dynamic analysis," the U.S. Cybersecurity and Infrastructure Security Agency (CISA) said last month.
In one July 2022 incident disclosed by Microsoft, the threat actor is said to have attempted to initially deploy QuantumLocker executables, only to follow it up with suspected Zeppelin ransomware binaries five hours later.
"Such an incident might suggest that DEV-0832 maintains multiple ransomware payloads and switches depending on target defenses or, alternatively, that dispersed operators working under the DEV-0832 umbrella might maintain their own preferred ransomware payloads for distribution," Redmond pointed out.
Among other tools utilized by DEV-0832 is a Go-based backdoor called PortStarter that offers the capability to alter firewall settings and open ports to establish connections with pre-configured command-and-control (C2) servers.
Vice Society, aside from taking advantage of living-off-the-land binaries (LOLBins) to run malicious code, has also been found attempting to turn off Microsoft Defender Antivirus using registry commands.
Data exfiltration is eventually achieved by launching a PowerShell script that transmits wide-ranging sensitive information, ranging from financial documents to medical data, to a hard-coded attacker-owned IP address.
Redmond further pointed out that the cybercrime group focuses on organizations with weaker security controls and a higher likelihood of a ransom payout, underscoring the need to apply necessary safeguards to prevent such attacks.
"The shift from a ransomware as a service (RaaS) offering (BlackCat) to a purchased wholly-owned malware offering (Zeppelin) and a custom Vice Society variant indicates DEV-0832 has active ties in the cybercriminal economy and has been testing ransomware payload efficacy or post-ransomware extortion opportunities," Microsoft said.