UAT-11795 deploys novel Starland RAT and bespoke WLDR C2 implant in financially motivated campaign

Cisco Talos is disclosing UAT-11795, a sophisticated, Russian-speaking, financially motivated adversary that has been conducting a malicious campaign targeting users in the U.S. and Europe since at least June 2025. The threat actor utilizes a Python-based remote access tool (RAT) called ‘Starland RAT’ and a command-and-control (C2) memory implant known as the ‘WLDR agent’. The WLDR agent is a sophisticated PowerShell-based C2 memory implant featuring encrypted beaconing, task queuing, and a Runspace execution engine for executing additional payloads.

UAT-11795 also employs CastleStealer and Remcos RAT as alternative payload implants. The actor targets victims’ credentials and cryptocurrency wallet assets, establishing a persistent connection to the victims’ machines from the C2 server, with the potential to deliver and execute further payloads.

Victimology: According to telemetry data, the infection is predominantly observed in the United States, with fewer potential impacts reported in Germany, Romania, and Venezuela.

Talos has observed that the threat actor has utilized trojanized installer lures from software categories including: developer tooling, IT administration utilities, enterprise collaboration platforms, and a consumer gaming application, suggesting an opportunistic, volume-driven distribution model targeting multiple victim profiles simultaneously.

Threat actor infrastructure: The threat actor operates a distributed infrastructure across two functional categories – payload staging and persistent C2 – with domain naming conventions designed to blend into legitimate traffic categories. Staging domains include “eorthopaedics[.]com” (likely a hijacked domain), “web-devtools[.]com” (resembles a developer tooling portal), and “zynaris[.]io” (resembles a technology start-up). “eorthopaedics[.]com” and “sastoro[.]com” host the PowerShell stage chain under “/feed/” and “/alpha/” paths, indicating that the actor has added the malicious routing alongside legitimate content. “web-devtools[.]com” serves raw shellcode payloads under the paths (“/starlandfox”, “/x32remka”, “/dopfile”) and a compressed archive. “zynaris[.]io” hosts the potential ClickFix-delivered HTML application (HTA) stager and trojanized installer lures. The C2 infrastructure is similarly distributed, with “eorthopaedics[.]com” and “sastoro[.]com” both serving hardware-bound unique identifier (HWID) encrypted envelopes over HWID parameterized URL paths with “eorthopaedics[.]com” under “/feed/” and “sastoro[.]com” under “/alpha/”. This suggests that the two domains represent parallel C2 infrastructure used for the same campaign. The domains “windowscreenrepairnearme[.]com” (which is also likely to be a hijacked domain) and “aipythondevs[.]com” serve as the primary C2 for the Starland Python RAT. All C2 URLs incorporate a victim hardware identifier derived from the C: drive volume serial number of the victim machine as the final URL path component, enabling the distinct C2 communication for each of the compromised victims. The actor has also implemented C2 infrastructure resilience by using a Polygon smart contract (“0x6ae382ed2154cc84c6672e4e908cd2c69c1b35ba”), which stores an XOR-encrypted fallback C2 domain that is retrievable via a public JSON-RPC call.

Talos discovered that the actor controls two Telegram bots, “8384531459” (“skuefq_bot”) and “7993597060” (“komandastuk_bot”), used for receiving the implant’s execution notification beacons, including messages with victim’s machine fingerprints and cryptocurrency wallet inventories. Talos’ research uncovered a private live Telegram channel called “stuk komanda”, controlled by the same threat actor. The stuk komanda channel was created on June 5, 2025, and has three unknown subscribers. It does not contain any chat groups and appears to be structured like a C2. The channel lists messages in the name of file names that appear to be Windows-based binaries, highlighting that the threat actor has been active since at least June 2025.

Multi-stage attack summary: The threat actor executed a multistage campaign that involves deploying a weaponized HTA downloader via Microsoft HTML Application Host (“mshta.exe”) on the victim's machine, likely utilizing a ClickFix technique. The execution of the HTA file results in the downloading and execution of trojanized installers bundled with a malicious Python package, which sends the implant status of the installer to an attacker-controlled Telegram bot. The NSIS script associated with the trojanized installer is designed to execute the malicious byte-compiled Python code encapsulated within the installer file.

This initial byte-compiled Python code acts as a loader that decodes and executes an embedded Python RAT, which we are calling Starland RAT, in the victim's machine memory. Starland RAT offers a wide range of functionalities and has been specifically engineered to operate within the Windows environment. Its capabilities include defense evasion techniques, system reconnaissance, stealing browser data and cryptocurrency wallets, and a fallback C2 connection mechanism that includes a hardcoded C2 URL, as well as a Polygon Ethereum smart contract that serves as a backup. This connection allows it to interact with the smart contract through Eth_call, dynamically resolving the C2 domains. The RAT sends the reconnaissance information to the C2 to register the victim's machine and is proficient in receiving and executing intermediate payloads in several formats, including shellcode for 64-bit and 32-bit Windows environments, directly executing Windows shell commands, and downloading and executing malicious EXE, MSI, and DLL files. Furthermore, Talos has observed that the threat actor executed a Windows shell command through Starland RAT as an intermediate payload to download and execute a PowerShell stager. This stager is associated with an undocumented PowerShell C2 framework, which we track as “WLDR C2” in alignment with the internal project designation used by the threat actor in the PowerShell scripts.

Initial vector: The threat actor gains initial access to the victim machine potentially through a ClickFix social engineering technique that entices the user to execute a command, which then stealthily downloads and executes a remotely hosted weaponized HTA file. The HTA file runs an embedded VBScript that drops a Windows batch file into the user profile’s application temporary folder, which contains instructions to first download and implant a trojanized installer from the attacker-controlled staging domain onto the victim machine.

Once the trojanized installer is executed, the batch file sends a notification beacon to an attacker-controlled Telegram bot, “8384531459”, to confirm successful execution to the threat actor. At the same time, the VBScript establishes persistence under “HKCU`Software`Microsoft`Windows`CurrentVersion`Run” with the generic value “MyApp”, pointing back to “mshta.exe” to execute the remotely hosted weaponized HTA file every time the victim logs in to the machine. Talos identified a Russian-language developer comment left in the VBScript (“Добавление команды в автозапуск для текущего пользователя”), indicating that a Russian-speaking actor is conducting this campaign.

Python loader packaged into trojanized installers: Talos has observed that the threat actor has weaponized software installers by utilizing the Nullsoft Scriptable Install System (NSIS). They have packaged the Python runtime executable “pythonw.exe” along with a compiled Python loader, which is disguised as a license file named “LICENSE.txt”. The threat actor has modified the NSI script file of the installer to include instructions for executing the compiled Python loader using the Python runtime executable.

The compiled Python loader is a relatively large file obfuscated with numerous junk functions that perform random arithmetic operations and print randomly generated strings to the standard output. The actual execution logic is confined to six lines in the loader program, implementing XOR decryption using the XOR key 198 (0xC6) to decrypt the encrypted embedded payload of Starland RAT and execute it in the victim machine's memory.