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UPD 03.07.2026: added a package of rules and recommendations that help detect the described malicious activity for companies using our Kaspersky SIEM system.
Introduction
To access compromised systems, threat actors frequently abuse legitimate remote monitoring tools. At first glance, these utilities rarely raise red flags: they are signed with valid digital certificates, often allowlisted under corporate IT policies, and fully supported by OS vendors. However, they grant attackers the ability to harvest data from target devices, drop malware, and move laterally across the network.
During a recent investigation engagement, the Kaspersky Managed Detection and Response (MDR) team discovered the ScreenConnect remote access tool being leveraged to deploy and execute an AsyncRAT payload.
A deep dive into this single incident unraveled a massive campaign distributing malicious installer archives hosted on spoofed websites. These installers masquerade as popular software like OBS Studio, DNS Jumper, DS4Windows, Bandicam, and others. In total, we uncovered more than 90 domain names localized across 10 languages. The malicious archives bundle a legitimate, signed Microsoft install.exe binary alongside a rogue install.res.1033.dll library. It is loaded onto the device via DLL sideloading and deploys the ScreenConnect service, which awaits further instructions from the threat actors.
As a result, what initially appeared to be an isolated ScreenConnect incident served as the starting point for a full investigation into the threat actor’s C2 infrastructure. Every spoofed site we uncovered followed the exact same playbook: dropping a hidden ScreenConnect remote administration service under the guise of a legitimate software installer. This allowed the attackers to maintain control over compromised endpoints, with victims ranging from individual users to organizations.
We continue to break down complex, multi-stage incidents like this in our ongoing The SOC Files series. In this post, we take a deep dive into the technical execution of the ScreenConnect attack and analyze the broader infrastructure under the threat actor’s control.
Initial incident investigation
The investigation was triggered by an alert from Kaspersky MDR, which flagged the creation and execution of suspicious PowerShell and VBS scripts spawned by a ScreenConnect process.
About ScreenConnect
ScreenConnect is a legitimate remote management utility. Kaspersky solutions detect it as not-a-virus:HEUR:RemoteAdmin.MSIL.ConnectWise.gen.
ScreenConnect was running as an Access-type service — enabling direct remote connectivity — with the server explicitly passed via the command line:
ScreenConnect service execution event with suspicious parameters
Once running, ScreenConnect created and executed a PowerShell script named Fj5NmEsp9EuKrun.ps1:
Malicious PowerShell script creation
Below is an excerpt from the contents of the script:
Snippet of Fj5NmEsp9EuKrun.ps1
This script configures Microsoft Defender exclusions for the following objects:
All disks in the system: C:\, D:\, and others
All root directories on the C:\ drive, as well as the C:\Users\Public directory
RegAsm.exe process
Additionally, the script disables User Account Control (UAC) prompts by setting the ConsentPromptBehaviorAdmin registry parameter to 0.
Following this setup, the ScreenConnect service goes on to create a VBScript file:
Malicious VBScript creation
The installer_method3_stream.vbs script creates five files in the C:\Users\Public directory (msgbox.txt, secret_bytes.txt, 1.vb, cap.ps1, and script.vbs) and immediately triggers their execution by launching script.vbs.
Contents of script.vbs
This script terminates all active powershell.exe processes to cover its tracks and executes cap.ps1 in a hidden window.
Contents of cap.ps1
cap.ps1 reads the contents of the secret_bytes.txt file, extracts sequences matching the [SXX- pattern, and converts XX from hexadecimal representation to a byte. It then uses a 0xA7 XOR key to decrypt each byte and inverts the bit order. The resulting byte array yields a fully formed PE binary, which is then reflectively loaded into the CLR.
Within the loaded assembly, the ConsoleApp1.Module1 type contains a static method named Run. The script uses reflection (Reflection.BindingFlags) to resolve a reference to this method and invoke it.
The Run method executes a process hollowing technique (T1055.012), spawning a new RegAsm.exe process with the CREATE_SUSPENDED flag. The deobfuscated and decrypted PE image from secret_bytes.txt is then copied into its address space. As a result, the RegAsm.exe process no longer executes its original code, instead serving as a container for the injected .NET module — which, in this case, is the AsyncRAT remote access Trojan.
To establish persistence, the malware schedules a task named MasterPackager.Updater:
This task triggers every two minutes, ensuring that script.vbs — and consequently the entire loader chain — executes even after a system reboot.
Once the entire infection chain successfully executes, the RegAsm.exe process establishes a connection to the C2 domain mora1987[.]work[.]gd.
AsyncRAT infection and persistence chain via ScreenConnect
How ScreenConnect entered the system
A retrospective analysis of the incident allowed us to pinpoint the source of the ScreenConnect installation: a user-downloaded archive named obs-studio-windows-x64.zip.
The archive was downloaded from hxxps://www.studioobs[.]com/, a typosquatted domain mimicking the official site for OBS Studio, a popular open-source screen recording app. This site is present in search engine results; in this specific incident, the user landed on the malicious domain directly from a search query, a vector we analyze in more detail below.
Clicking the download button for the supposedly legitimate software triggers a request to the following URL, from which the archive is fetched:
The archive contains a legitimate, Microsoft-signed executable named install.exe (87603EA025623B19954E460ADD532048), renamed to masquerade as the OBS Studio installer, along with a malicious library named install.res.1033.dll. Additionally, the archive includes an Assets folder containing both a copy of the actual software being impersonated and the ScreenConnect utility.
Contents of obs-studio-windows-x64.zip
The complete file structure of the archive is organized as follows:
Detailed directory tree of obs-studio-windows-x64.zip
When OBS-Studio-Installer.exe is executed, it loads install.res.1033.dll via DLL sideloading. This library contains the instructions required to install both ScreenConnect and OBS Studio. The deployment relies on native Windows utilities (msiexec.exe), but the attackers renamed the standard MSI packages to look like DLL files:
Once the installation wraps up, a new service named Microsoft Update Service is created. The command line for this service explicitly defines the connection server as r[.]servermanagemen[.]xyz.
Meanwhile, the MSI package for the actual OBS Studio software runs using a standard graphical user interface.
ScreenConnect and OBS Studio installation workflow
Expanding the investigation
The attackers’ reliance on the legitimate install.exe binary provided a crucial pivot point for our broader investigation. We discovered that this specific file was being deployed in the wild under a variety of suspicious aliases, including:
ds4windows.exe
crosshairx_installer.exe
obs-studio-installer.exe
dns jumper.exe
glary utilities pro.exe
processhacker-2.39-setup.exe
These file names indicate that the threat actor was disguising their ScreenConnect archives as popular utilities beyond OBS Studio. Among the fakes, we identified counterfeit installers for DS4Windows, DNS Jumper, Glary Utilities, and Process Hacker. Crucially, when we search for these utilities on major search engines, these fraudulent sites frequently appear at the very top of the organic search results. This indicates that the threat actor is actively leveraging SEO techniques to boost traffic to their landing pages.
Spoofed software portals appearing in search engine results
For example, here is how the fraudulent download portal for DNS Jumper looks:
Fake website mimicking the official DNS Jumper resource
On this page, the download button directs users to the following address:
Just like the OBS Studio variant, this drops an archive onto the victim’s device with an identical structure: a renamed legitimate install.exe file, a sideloaded library, and an Assets directory containing the promised software packaged alongside ScreenConnect.
Contents of the DNS Jumper and ScreenConnect archive
Other fraudulent websites that appear in search engine results when querying the corresponding software are designed in a similar fashion.
Spoofed websites used to distribute ScreenConnect
Notably, the vast majority of the fraudulent sites we uncovered are localized into English, Russian, and Chinese. In several instances, the pages were also translated into German, French, Spanish, Arabic, and other languages. This multi-language support underscores the global footprint of the campaign, targeting a broad user base across multiple regions.
Language localization options on a ScreenConnect delivery site
Fake domain infrastructure
To distribute ScreenConnect disguised as freeware, the threat actor spun up an extensive network of domain names mapped across three IP addresses. We have categorized these into two distinct infrastructure clusters.
Cluster 1: 162.216.241[.]242 and 198.23.185[.]81
```
162.216.241[.]242
Country: United States
Org name: Dynu Systems Incorporated
```
The connection graph below illustrates the campaign websites tied to IP address 162.216.241[.]242, which hosts the previously mentioned www[.]studioobs[.]com domain.
URL connection graph for IP 162.216.241[.]242
Looking into the registration dates for the domains on this IP, we found that the threat actor initially attempted to disguise their sites as various gaming portals:
Subsequently, starting in January 2026, they shifted strategy and began registering fake domains designed to mimic popular freeware:
In this specific branch of the ScreenConnect campaign, the malicious archives are hosted on fileget.loseyourip[.]com. Notably, the download resource is hosted on a completely separate provider:
```
198.23.185[.]81
Country: United States
Org name: NOHAVPS LLC
```
Our analysis of this second IP address revealed that it also hosts additional resources tied to the campaign, including fake gaming sites and supplementary download links:
Below is an infrastructure graph showing this IP address and its hosted domains. Notably, unlike the previous case, this address also hosts direct-download.giize[.]com, a resource used to store distributed malicious archives.
URL connection graph for IP 2.59.134[.]97
In this branch of the campaign, the threat actor skipped game-themed lures entirely, focusing exclusively on creating fraudulent freeware sites that bundled ScreenConnect with the requested application. The domains hosted on IP address 2.59.134[.]97 were registered between October 2025 and March 2026.
The chart below shows the volume of fraudulent websites created month by month:
Breakdown of ScreenConnect delivery sites by theme, August 2025 through March 2026 (download)
C2 infrastructure analysis
In total, we identified dozens of different archives distributed across this campaign. All of them share a uniform file structure, containing the malicious install.res.1033.dll library and the ScreenConnect MSI package located at Assets\x86\vcredist_x64.dll.
In some instances, the ScreenConnect installation package also bundles a CAB archive.
Contents of the CAB archive
This archive contains a system.config XML file, which defines the connection address for the ScreenConnect C2 server:
Contents of system.config
By analyzing these ScreenConnect installations, we uncovered additional C2 addresses, which are mapped out in the following graph:
Connection graph of ScreenConnect C2 domains
The next graph illustrates the AsyncRAT command-and-control infrastructure:
AsyncRAT C2 server infrastructure
Based on the registration dates of the C2 domains, we can determine that the campaign was launched in October 2025 and paused at the end of March. However, at the time of publication, many of the landing pages remain accessible via search engine results.
Takeaways
Investigating a single case of AsyncRAT delivered via ScreenConnect allowed us to uncover a massive, multi-domain, multi-language infrastructure designed to distribute a hidden installer for this software and further advance the attack. The threat actor disguises ScreenConnect as popular utilities and distributes it through fraudulent websites that mimic official product pages. The attackers leverage search engine optimization techniques to push these sites to the top of search results in engines like Google and Bing.
This attack chain targets both everyday consumers downloading free software from the internet and corporate networks, where remote access tools are frequently allowlisted and granted elevated privileges.
The potential objective of the campaign is to steal credentials en masse and gain unauthorized access to systems for subsequent resale on dark web marketplaces.
To mitigate the risks associated with this threat, we recommend implementing the following security measures:
Enforce strict software installation controls: application allowlisting and blocking MSI package execution from untrusted sources
Continuously monitor for the creation of new remote administration services and scheduler tasks
Filter outbound traffic to unknown domains and IP addresses
Regularly train users on safe downloading practices
Verify the authenticity of all software sources
For enterprise users, credential monitoring is a critical mitigation strategy against the risks detailed in this article, as a leaked account or compromised system access frequently serves as a vector for subsequent attacks on the organization. Kaspersky Digital Footprint Intelligence provides continuous data monitoring across open and dark web sources, enabling security teams to respond proactively to potential threats.
Malicious code injection into the RegAsm.exe process — leveraged by attackers to masquerade execution behind a trusted system component — is detected via the code_injection_to_unusual_process rule.
To visualize the stages of the attack, security teams can utilize Kaspersky Cloud Sandbox on the Threat Intelligence portal. For instance, this tool allows defenders to map out the entire deployment and payload execution chain originating from the initial VBS dropper.
Furthermore, the Kaspersky Threat Intelligence portal supports searching and graphing the connections between malicious domains and files involved in this campaign, as demonstrated in our adversary infrastructure analysis section.
Finally, the Similarity engine within Kaspersky Threat Analysis profiles file contents to hunt down samples resembling the original threat, helping organizations identify new or previously undetected malicious objects.
To protect companies using our Kaspersky SIEM system, there are rules available in the product repository to help detect this type of malicious activity.
Adding exclusions to Windows Defender scans via the registry is detected by rule R241_Modification of Windows Defender exclusions through the registry. Adding exclusions via PowerShell (Add-MpPreference -ExclusionPath|ExclusionProcess) is detected by rule R076_04_Windows Defender settings disabled or changed via PowerShell.
Bypassing the UAC mechanism by modifying the ConsentPromptBehaviorAdmin registry key is detected by rule R242_UAC disabled through the Windows registry.
Running VBS scripts from a public directory triggers rule R290_07_Running VBScript files from shared folders.
Creating a scheduled task that runs an executable file from a public directory triggers rule R099_01_Scheduled task started from a public folder.
For the rules to function correctly, it is necessary to configure event 4657 (Security) audit for the following registry keys:
Additionally, when developing your own detection rules or conducting threat hunting for suspicious ScreenConnect behavior, we recommend monitoring the following events:
Creation of the ScreenConnect service with suspicious parameters
DeviceEventClassID = '4697'
AND FileName LIKE '%ClientService.exe%'
AND (FileName LIKE '%e=Access%' OR FileName LIKE '%e=Support%')
Launch of atypical child processes from the ScreenConnect service
DeviceEventClassID = '4688'
AND match(SourceProcessName, '.*\\\\ScreenConnect\\.(ClientService|WindowsClient|WindowsBackstageShell|WindowsFileManager)\\.exe')
AND match(DestinationProcessName, '.*\\\\(powershell|cmd|net|schtasks|sc|msiexec|mshta|rundll32)\\.exe')
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