ATT&CKCampaigns3CX Supply Chain Attack

3CX Supply Chain Attack

C0057

Campaign, Nov 2022 to Mar 2023.View on attack.mitre.org

About this campaign

The 3CX Supply Chain Attack was the first publicly reported case of one supply chain compromise triggering another, leading to a cascading, two-stage intrusion. The initial supply chain attack began when a 3CX employee downloaded and executed a trojanized, end-of-life version of the X_Trader trading software from Trading Technologies. This provided UNC4736, a threat cluster associated with AppleJeus, access to the 3CX environment. From there UNC4736 compromised the Windows and macOS build environments used to distribute the 3CX desktop application to their customers. While 3CX serves more than 600,000 customers and 12 million users, only a subset of systems were affected. Subsequent targeting focused on victims in the defense and cryptocurrency sectors, where attackers deployed secondary payloads such as Gopuram for credential theft and persistence. The campaign began in late 2022 and was disrupted after security vendors publicly reported the compromise in March 2023.

Techniques used22

Procedure examples22

TechniqueProcedure example
T1027
Obfuscated Files or Information

During the 3CX Supply Chain Attack, AppleJeus payloads use AES-256 GCM cipher to encrypt data to include ICONICSTEALER and VEILEDSIGNAL.

T1027.009
Embedded Payloads

During the 3CX Supply Chain Attack, AppleJeus uses embedded .dll as apart of a chained delivery mechanism to invoke the COM class factory.

T1027.013
Encrypted/Encoded File

During the 3CX Supply Chain Attack, AppleJeus encrypts its dynamic library files (.dll) using RC4, and when loaded only decrypts specific portions of the file using the key `3jB(2bsG#@c7`.

T1055
Process Injection

During the 3CX Supply Chain Attack, AppleJeus's VEILEDSIGNAL uses process injection to inject the C2 communication module code in the first found process instance of Chrome, Firefox, or Edge web browsers. It also monitors the established named pipe and re-injects the C2 communication module if necessary.

T1055.002
Portable Executable Injection

During the 3CX Supply Chain Attack, AppleJeus uses the SigFlip tool to inject arbitrary code without affecting or breaking the file's signature.

T1071.001
Web Protocols

During the 3CX Supply Chain Attack, AppleJeus's COLDCAT C2 leverages cookie headers to contain data over HTTPS. Cookies also contain hardcoded variables `__tutma` or `__tutmc` in the payload's HTTPS request.

T1078
Valid Accounts

During 3CX Supply Chain Attack, AppleJeus has gained access to the 3CX corporate environment through legitimate VPN credentials.

T1102.001
Dead Drop Resolver

During the 3CX Supply Chain Attack, AppleJeus leveraged a GitHub repository to host icon files containing the command and control URL.

T1189
Drive-by Compromise

During the 3CX Supply Chain Attack, AppleJeus compromised the `www.tradingtechnologies[.]com` website hosting a hidden IFRAME to exploit visitors, two months before the site was known to deliver a compromised version of the X_TRADER software package.

T1195.002
Compromise Software Supply Chain

During the 3CX Supply Chain Attack, AppleJeus first compromised an “end-of-life" trading software application which was downloaded and executed inside the 3CX enterprise environment. The second compromise modified the Windows and macOS build environments used to distribute the 3CX software to their customer base.

T1203
Exploitation for Client Execution

During the 3CX Supply Chain Attack, AppleJeus leveraged the Chrome vulnerability, CVE-2022-0609, in combination with a Drive-by Compromise website.

T1217
Browser Information Discovery

During the 3CX Supply Chain Attack, AppleJeus leveraged ICONICSTEALER to steal browser information to include browser history located on the infected host.

T1218.007
Msiexec

During the 3CX Supply Chain Attack, AppleJeus delivered components using a Windows Installer package (.msi). The MSI installer extracted several files and executed the 3CXDesktopApp.exe, which loaded the malicious library file ffmpeg.dll.

T1218.015
Electron Applications

During the 3CX Supply Chain Attack, AppleJeus leveraged the 3CX application's electron framework to execute its malicious libraries under the official 3CX electron application.

T1543.004
Launch Daemon

During the 3CX Supply Chain Attack, AppleJeus installs a Launch Daemon to execute the POOLRAT macOS backdoor software.

View all 22 procedure examples

Attributed groups1

Software1

References4

  1. 3cx official statement 2023 Open source
    Agathocles Prodromou. (2023, April 20). Security Update Thursday 20 April 2023 – Initial Intrusion Vector Found. Retrieved August 25, 2025.
  2. Kaspersky 3CX Gopuram 2023 Open source
    Georgy Kucherin, Vasily Berdnikov, Vilen Kamalov. (2023, April 3). Not just an infostealer: Gopuram backdoor deployed through 3CX supply chain attack. Retrieved August 25, 2025.
  3. Krebs 3cx overview 2023 Open source
    Brian Krebs. (2023, April 20). 3CX Breach Was a Double Supply Chain Compromise. Retrieved May 22, 2025.
  4. Mandiant 3cx UNC4736 2023 Open source
    Jeff Johnson, Fred Plan, Adrian Sanchez, Renato Fontana, Jake Nicastro, Dimiter Andonov, Marius Fodoreanu, Daniel Scott. (2023, April 20). 3CX Software Supply Chain Compromise Initiated by a Prior Software Supply Chain Compromise; Suspected North Korean Actor Responsible. Retrieved August 25, 2025.

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