Good Game, Gone Bad: Xeno RAT Spread Via .gg Domains and GitHub

Introduction

XenoRAT, an open-source malware available on GitHub, has been linked to a North Korean hacking group and unnamed threat actors preying on the gaming community. Recently, Hunt’s Research Team discovered the remote access tool (RAT) spreading through .gg domains, a term synonymous with “good game” in esports, and a GitHub repository portraying its software as scripting engine tools for the popular game Roblox.

In this post, we’ll explore the specific .gg domains hosting Xeno RAT, the GitHub account, and a possibly linked YouTube account and provide insight into how this emerging threat targets gamers and developers.

Xeno RAT in the Wild

Most recently, AhnLab’s ASEC reported on a likely North Korea-linked group using Dropbox to deliver Xeno RAT to victim networks. In late April, a third-party researcher on X posted on an open directory likely administered by the Kimsuky threat group, hosting a copy of the tool in a folder titled “/rat.”

The tools GitHub page boasts several advanced features, including HVNC, real-time audio surveillance, and a SOCKS5 reverse proxy. The README, detailing these capabilities, is pictured below in Figure 1.

A Closer Look at Xeno RAT Network Traffic

Communication between the controller and Xeno RAT clients occurs over TCP sockets, as illustrated in Figure 2. The initial exchange follows a recognizable pattern, which can help identify malicious activity.

Additionally, C2 servers respond to requests in the same pattern as the one seen below. For an in-depth talk on detecting malware infrastructure according to controller responses, we recommend Greg Lesnewich's LABScon23 talk.

If you're in need of robust network IDS rules (Suricata/Snort) to detect these servers, check out @Jane0sint’s contributions on the Emerging Threats website.

Discovery of Xeno RAT C2s on .gg Domains

Xeno RAT infrastructure hosted on .gg domains spotlights a troubling trend in malware distribution as the top-level domain (TLD) is popular in the esports community and is now being exploited to spread malware.

This section will provide an overview of controller domains and the associated clients.

Examples

The following section provides a detailed list of identified .gg domains hosting XenoRAT controllers, the resolving IP addresses, and the sandbox analysis results.

Each domain was hosted on one of three shared IP addresses belonging to the Developed Methods LLC ASN in the U.S. Notably, IP 147.185.221_19 also served as controller infrastructure for DcRAT and VenomRAT, as seen in Figure 3. Additionally, this same IP hosted a C2 server for Redline Stealer just last month.

The GitHub Repo

During our analysis, one file name stood out among those communicating with the .gg domains: SynapseX.revamped.V1.2.rar. This file led us to a GitHub repository (Figure 4) under an account claiming to own Synapse X Revamp, a scripting engine for Roblox. The account hosts 10 repositories, most disguised as gaming-related executors and named loader.exe.

When extracted, the .rar file, as mentioned above, contains two executables: Synapse X Launcher.exe.exe and Synapse X Launcher.exe. The first file is identified as XenoRAT, while the latter is detected as Quasar, a well-known malware family also written in .NET. Sandbox results for both files are displayed below.

The C2 server for Quasar uses portmap.io, a free port forwarding service. Interestingly, suppose you’re a fan of animated YouTube series or have young children. In that case, you might recognize that the domain name resembles Skibidi Toilet, a popular machinima series featuring videos and shorts.

Details

Details for the Quasar sample:

Hunt researchers weren't the first to uncover this repository's malicious nature. Two weeks ago, a GitHub user named ByfronTechnologies submitted an issue, complete with screenshots from Hatching Triage, indicating that the file in the XMainDab folder was detected as XWorm malware. Figure 7 includes a screenshot of the comment and the analysis images.

By pivoting on the file and folder names in the repository, we discovered what appears to be the YouTube channel associated with this threat actor. The account, named P-Denny Gaming (Figure 8), features several videos related to Roblox. The video titles use similar names to those found in the GitHub account, further linking the two.

Figure 9 shows a screenshot from one of the videos instructing users to disable Windows Defender before installing the Synapse X RAR file. Notably, the screenshot reveals that the user's Windows desktop uses the Swedish language and includes a browser bookmark labeled 'Roblox Stealer,' providing additional context about the actor's intent.

In the same video, several comments vouched for the legitimacy of the files, dismissing warnings from other users who had correctly identified the software as malicious.

Potential Impacts on the Gaming Community

The presence of XenoRAT and other malware on .gg domains and GitHub poses significant risks to the gaming community. Gamers and developers are particularly vulnerable to these threats due to the seamless integration of malicious software into legitimate-looking tools and resources.

Malicious software like those mentioned above can lead to the theft of personal information, in-game assets, and financial data, severely impacting users' digital lives. Furthermore, using open-source platforms like GitHub to distribute malware disguised as game scripts or executors increases the likelihood of widespread infection.

Note: Hunt is actively scanning for XenoRAT infrastructure using its default port, 4444. Our detection methods for these servers have proven effective; we plan to expand our monitoring to include all ports, ensuring comprehensive coverage in identifying and tracking C2 servers. Stay tuned for updates on our progress.

Conclusion

Hunt has identified several Xeno RAT samples that distribute malware by leveraging .gg domains and a GitHub account. Both pieces of malicious software pose a significant threat to the gaming community.

Users must remain vigilant and exercise caution when downloading and installing software, regardless of the platform. A healthy dose of caution can help mitigate the risks associated with these threats, ensuring a safe online gaming environment.

Contact us for a demo today, and join a community committed to seeking out and exposing malicious infrastructure wherever it may rear its ugly head.