Supply Chain Compromise Leads to Trojanized Installers for Notezilla, RecentX, Copywhiz

Executive Summary

On Tuesday, June 18th, 2024, Rapid7 initiated an investigation into suspicious activity in a customer environment. Our investigation identified that the suspicious behavior was emanating from the installation of Notezilla, a program that allows for the creation of sticky notes on a Windows desktop. Installers for Notezilla, along with tools called RecentX and Copywhiz, are distributed by the India-based company Conceptworld at the official domain conceptworld[.]com. After analyzing the installation packages for all three programs, Rapid7 discovered that the installers had been trojanized to execute information-stealing malware that has the capability to download and execute additional payloads.


On Monday, June 24th, 2024, Rapid7 contacted Conceptworld to disclose the backdoored installers being hosted on conceptworld[.]com in accordance with Rapid7’s vulnerability disclosure policy. Within 12 hours, Conceptworld confirmed and remediated the issue by removing the malicious installers from conceptworld[.]com and replacing them with legitimate, signed copies. Rapid7 is grateful to Conceptworld for their prompt action on this issue.


Conceptworld is an India-based company offering three different software products: Notezilla, which allows users to create sticky notes on a Windows desktop; RecentX, which stores recently used files/applications/clipboard data; and Copywhiz, which improves file copying and backup operations. A free trial download is available on the official conceptworld[.]com site for each software package.

The installation packages being served by conceptworld[.]com at the time of investigation, however, executed malware alongside the legitimate installer, were not signed, and did not match the file size stated on the download page. The differences in the file sizes are due to the malware and its dependencies, which increases the size of the compromised installation packages.

FilenameSHA256 HashFilesizeNotes
NotezillaSetup.exe6f49756749d175058f15d5f3c80c8a7d46e80ec3e5eb9fb31f4346abdb72a0e717.07 MBTrojanized.
NotezillaSetup.exe51243990ef8b82865492f0156ebbb23397173647c02a0d83cf3e3dfb4ef8a6bc15.19 MBLegitimate, signed by Conceptworld.
RecentXSetup.exe4df9b7da9590990230ed2ab9b4c3d399cf770ed7f6c36a8a10285375fd5a292f15.79 MBTrojanized.
RecentXSetup.exea6ad6492e88bdb833d34ac122c266f1fadd9509ecfe0246e283728e4af49f43313.92 MBLegitimate, signed by Conceptworld.
CopywhizSetup.exe2eae4f06f2c376c6206c632ac93f4e8c4b3e0e63eca3118e883f8ac479b2f85214.14 MBTrojanized.
CopywhizSetup.exefd8d13123218f48c6ab38bf61d94113b4d97095e59fb415e6aa5d9ada012206e12.27 MBLegitimate, signed by Conceptworld.

The malware Rapid7 observed contains the functionality to steal browser credentials and crypto currency wallet information, log clipboard contents and keystrokes, and download and execute additional payloads. After infecting a system, the malware persists via a scheduled task that executes the primary payload every three hours.

Based on file submissions to VirusTotal, the malicious copies of the installers have existed since early June of 2024. The malware payloads delivered by the trojanized installers, however, seem to belong to a nameless malware family that has been in distribution since at least January of 2024. Rapid7 internally refers to this malware family as dllFake because of the naming scheme used for several of the malware payloads.

Malicious installer nameVirusTotal First Submission
NotezillaSetup.exe2024-06-10 06:43:34 UTC
RecentXSetup.exe2024-06-07 21:38:11 UTC
CopywhizSetup.exe2024-06-08 07:25:17 UTC

Technical analysis

To take a deeper look at the malware payloads, we will analyze the malicious installer that was served for Notezilla.

Initial Access

Rapid7 determined that trojanized installers for the 32-bit and 64-bit versions of Notezilla, Copywhiz, and RecentX were, at the time of investigation, being served from the official website conceptworld[.]com. Any users searching for this software via a popular search engine at the time were most likely to find the official domain as the first result, which would then have directed them to download the malware.


The installer served by conceptworld[.]com for Notezilla at the time of investigation was NotezillaSetup.exe, which, based on static analysis, is packed using software called Smart Install Maker(5.04).

Figure 1. Software Properties of NotezillaSetup.exe.

Using the sim_unpacker plugin for the tool UniExtract2, we were able to unpack and acquire most of the contents of the installation package, such as the embedded files and configuration information. The configuration file contains references to the legitimate software installer for Notezilla, which is dropped into %TEMP% during execution, and multiple files that are dropped into the installation directory (i.e., staging folder) %LOCALAPPDATA%\Microsoft\WindowsApps\ during execution.

Installer Files

Figure 2. Output from Using the sim-unpacker tool.

Figure 3. Contents of installer.config.

Once executed, NotezillaSetup.exe will then execute the file dllCrt32.exe from the staging directory %LOCALAPPDATA%\Microsoft\WindowsApps\ via a WINAPI call to ShellExecuteA with the verb open. A second call is then made to ShellExecuteA to execute the file NotezillaSetup.exe, a copy of the legitimate installer, from %TEMP%. As a result, the only thing seen by the end user after initial execution is the installation window pop-up for the legitimate installer, prompting the user to proceed with the installation process for Notezilla.

Figure 4. Typical Process Tree for Initial Execution of the Trojanized Installer.

Figure 5. The User’s View after the Infection has Already Begun in the Background.

The file dllCrt32.exe is a relatively small (~10KB) program that only serves as a wrapper to call CreateProcessA to execute the file dllCrt.bat.

Figure 6. The Contents of dllCrt.bat.

The batch file dllCrt.bat will then create a hidden scheduled task named Check dllHourly32 using schtasks.exe and an XML file that was previously dropped into the staging directory at %LOCALAPPDATA%\Microsoft\WindowsApps\dllCrt.xml. The scheduled task Check dllHourly32 will then execute the file %LOCALAPPDATA%\Microsoft\WindowsApps\dllBus32.exe every three hours after being initially created, which means that the primary malware payload will not be executed until at least three hours after the user originally executed the trojanized installer.

Figure 7. Command Line Assembly within dllBus32.exe.

When dllBus32.exe is executed, it also serves as a small wrapper for calling CreateProcessA, though it initially retrieves several important command line parameters. First, a call to the CRT library function sprintf concatenates a hard-coded IPv4 address. Then, a second call to sprintf concatenates the assembled IPv4 address with several other arguments to be passed to the batch file dllBus.bat. Finally, CreateProcessA is called with the fully assembled command line.

Figure 8. The Initial Lines of dllBus.bat.

The command line arguments passed to dllBus.bat via dllBus32.exe contain an IPv4 address, an SFTP port, a password for ZIP archive payloads, two sets of SFTP credentials, and the staging directory where the majority of the malware’s files are located.

Argument #PurposeValueNotes
1C2 IPv4 Address212.70.149[.]210Stored within dllBus32.exe.
2SFTP Port2265Used for all curl requests regardless of the IPv4 address.
3ZIP passwordMnX!8fsGt0@Used to decrypt/extract downloaded archives.
4SFTP Usernamephn_sysThe SFTP credentials used for uploading stolen data.
5SFTP PasswordPassword for phn_sys.
6SFTP Usernamephn_prjThe SFTP credentials used for downloading payloads.
7SFTP PasswordPassword for phn_prj

The batch file dllBus.bat contains functionality to facilitate the theft of information from Google Chrome, Mozilla Firefox, and multiple cryptocurrency wallets. The copy of curl.exe dropped by the installer is also used to connect to a list of command-and-control (C2) addresses hosting SFTP servers. The curl commands are used to download an updated list of C2 addresses, stored as plaintext within the file dll_srv.txt, and to download and execute additional payloads saved within encrypted ZIP archives named, and The batch script will also attempt to compress all files on the infected system that have specific file extensions and exist in directories that are not on a hardcoded blacklist (for exfiltration). All stolen data is ultimately compressed using 7z.exe and uploaded directly to the selected C2 SFTP server using curl.

Targeted Browsers
Mozilla Firefox
Google Chrome
Targeted Crypto Wallets
Jaxx Liberty
Targeted File ExtensionsBlacklisted File Path Strings
txt,doc,png,jpg“*icrosoft*”,”*indows*”,”*otoshop*”,”*rogram Files*”,”*rogramData”,”All Users”,”AppData”,”Default”,”Public”

The payloads and both contain executables created using PyInstaller, which means the original Python script used to create the executables can be recovered trivially using a publicly available extractor. The payload dllChrome32.exe, contained within, is used to facilitate theft of credentials from Google Chrome’s database that are then saved into the file %TEMP%\chrm.txt with the format: URL, Username, Password.

Figure 9. Primary Functionality of dllChrome32.exe.

The payloads dllTemp32.exe and dllCache32.exe stored within contain a clipboard stealer and a keylogger, where the results are saved to the files cl.txt and kl.txt, respectively, within the staging directory at %LOCALAPPDATA%\Microsoft\WindowsApps\.

Figure 10. All Data Copied to the Clipboard is Dumped to cl.txt when dllTemp32.exe is Running.

Figure 11. dllCache32.exe Logs Keystrokes to kl.txt when Running.

Rapid7 did not observe any of the identified SFTP servers hosting the third payload,, at the time of writing, although the contents of dllBus.bat indicate that it contains the executables srvBus32.exe and srvCrt32.exe, which serve an unknown function.

Mitigation Guidance

Rapid7 recommends verifying the file integrity of freely available software. Check that the file hash and properties of the downloaded file(s) match those provided by the official distributor and/or that they contain a valid and relevant signature. The malicious installers observed in this case are unsigned and have a file size that is inconsistent with copies of the legitimate installer, even as noted on the official download page.

If an installer for Notezilla, RecentX, or Copywhiz has been executed on a system within the last month, Rapid7 recommends checking for signs of compromise due to the malicious installers detailed in this blog. The primary indicators of infection include the hidden scheduled task Check dllHourly32 and a persistent running instance of the Windows Command Prompt, cmd.exe, which makes outbound network connections via curl.exe.

If evidence of compromise is found, Rapid7 recommends re-imaging affected systems to a known good baseline to eradicate any changes made by the malware.

Rapid7 Customers

InsightIDR, Managed Detection and Response, and Managed Threat Complete customers have existing detection coverage through Rapid7’s expansive library of detection rules. Rapid7 recommends installing the Insight agent on all applicable hosts to ensure visibility into suspicious processes and proper detection coverage. Below is a non-exhaustive list of detections that are deployed and will alert on behavior related to this activity:

Persistence – SchTasks Creating A Task Pointed At Users Temp Or Roaming Directory
Attacker – Extraction Of 7zip Archive With Password
Suspicious Process – 7zip Executed From Users Directory
Suspicious Process – TaskKill Executed Successively In Short Time Period
Attacker Technique – Curl or Wget To Public IP Address With Non Standard Port

MITRE ATT&CK Techniques

Resource DevelopmentT1584.004: Compromise Infrastructure: ServerThe threat actor gained access to the official domain responsible for serving software downloads.
Initial AccessT1195.002: Supply Chain Compromise: Compromise Software Supply ChainThe threat actor trojanized copies of the legitimate installers being served on the official website, to execute malware.
ExecutionT1204.002: User Execution: Malicious FileUsers are tricked into executing the malicious installer as it is served from the official website.
ExecutionT1059.003: Command and Scripting Interpreter: Windows Command ShellMuch of the malware’s functionality is facilitated through batch script files.
ExecutionT1059.006: Command and Scripting Interpreter: PythonSeveral second stage payloads were created using PyInstaller.
ExecutionT1053.005: Scheduled Task/Job: Scheduled TaskInitial execution of the primary batch script is delayed by at least 3 hours by the creation of a scheduled task.
PersistenceT1053.005: Scheduled Task/Job: Scheduled TaskThe malware is executed every 3 hours and will persist through reboots.
Credential AccessT1555.003: Credentials from Password Stores: Credentials from Web BrowsersThe malware decrypts and dumps credentials from Google Chrome and Mozilla Firefox.
CollectionT1560.001: Archive Collected Data: Archive via UtilityStolen data is archived via 7z.exe.
CollectionT1115: Clipboard DataA second stage malware payload dumps all clipboard data to disk.
CollectionT1005: Data from Local SystemThe malware compresses and steals files according to a file extension list and directory path strings blacklist.
CollectionT1056.001: Input Capture: KeyloggingA second stage malware payload logs keystrokes to disk.
Command and ControlT1571: Non-Standard PortThe threat actor uses port 2265 for SFTP instead of the default: 22.
ExfiltrationT1048: Exfiltration Over Alternative ProtocolThe malware uploads stolen data to C2 servers using SFTP via curl.

Indicators of Compromise

Network-Based Indicators (NBIs)

Domain/IPv4 AddressNotes
conceptworld[.]comThe official domain that was serving malicious installers.
5.180.185[.]42C2 IPv4 address hosting an SFTP server.
50.2.108[.]102C2 IPv4 address hosting an SFTP server.
50.2.191[.]154C2 IPv4 address hosting an SFTP server.
104.140.17[.]242C2 IPv4 address hosting an SFTP server.
104.206.2[.]18C2 IPv4 address hosting an SFTP server.
104.206.57[.]117C2 IPv4 address hosting an SFTP server.
104.206.95[.]146C2 IPv4 address hosting an SFTP server.
104.206.220[.]113C2 IPv4 address hosting an SFTP server.
170.130.34[.]114C2 IPv4 address hosting an SFTP server.
185.137.137[.]74C2 IPv4 address hosting an SFTP server.
212.70.149[.]210C2 IPv4 address hosting an SFTP server.

Host-Based Indicators (HBIs)

NotezillaSetup.exe6F49756749D175058F15D5F3C80C8A7D46E80EC3E5EB9FB31F4346ABDB72A0E7Trojanized installer package.
NotezillaSetup32.exeBFA99C41AECC814DE5B9EB8397A27E516C8B0A4E31EDD9ED1304DA6C996B4AAATrojanized installer package.
CopywhizSetup.exe2EAE4F06F2C376C6206C632AC93F4E8C4B3E0E63ECA3118E883F8AC479B2F852Trojanized installer package.
CopywhizSetup32.exe048CAE10558CDDFB2CF0ADE25F1101909BBA58D0A448E0D78590CC5E64E95127Trojanized installer package.
RecentXSetup.exe4DF9B7DA9590990230ED2AB9B4C3D399CF770ED7F6C36A8A10285375FD5A292FTrojanized installer package.
RecentXSetup32.exeEBF2B84ED64629242F8D0ABFCA73344736205249539474E8F57D1D3DBE8CCC41Trojanized installer package.
dllBus.bat1FA84B696B055F614CCD4640B724D90CCAD4AFC035358822224A02A9E2C12846Batch script that coordinates execution of other payloads and performs exfiltration of stolen data.
dllCrt.xmlCDC1F2430681E9278B3F738ED74954C4366B8EFF52C937F185D760C1BBBA2F1DUsed to create a scheduled task for persistence.
dllCrt32.exeFDC84CB0845F87A39B29027D6433F4A1BBD8C5B808280235CF867A6B0B7A91EBExecutes dllCrt.bat.
dllCrt.batA89953915EABE5C4897E414E73F28C300472298A6A8C055FCC956C61C875FD96Creates a scheduled task using dllCrt.xml.
dllBus32.exe70BCE9C228AACBDADAAF18596C0EB308C102382D04632B01B826E9DB96210093Executes dllBus.bat with multiple command line arguments.
Apps.zipCA6FF18EE006E7AB3CB42FC541B08CE4231DADFAB0CCE57B1C126DB3DF9F1297Encrypted archive that contains the payloads dllTemp32.exe and dllCache32.exe.
dllTemp32.exe33E4D5EED3527C269467EEC2AC57AE94AE34FD1D0A145505A29C51CF8E83F1B9Steals data from the clipboard during execution.
dllCache32.exe03761D9FD24A2530B386C07BF886350AE497E693440A9319903072B93A30C82DLogs keystrokes during execution.
Updt.zip6487A0DC9DFBBAA6557AF096178A1361E49762A41500AA03F17DF5D3B159BF4EEncrypted archive that contains dllChrome32.exe.
dllChrome32.exeDE4E03288071CDEBE5C26913888B135FB2424132856CC892BAEA9792D6C66249Decrypts and dumps credentials from the Google Chrome database if present.

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