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HighPublic exploit

3CX DesktopApp Supply Chain Compromise

IdentifiersCVE-2023-29059CWE-494

CVE-2023-29059 refers to a supply-chain compromise of the 3CX DesktopApp in which legitimate, digitally signed Windows and macOS application builds were distributed with embedded malicious code. Affected versions include Windows Electron DesktopApp builds 18.12.407 and 18.12.416 shipped in Update 7, and macOS Electron DesktopApp builds 18.11.1213, 18.12.402, 18.12.407, and 18.12.416. On Windows, the malicious activity was delivered through a DLL sideloading chain involving 3CXDesktopApp.exe, a clean loader d3dcompiler_47.dll, and a maliciously patched ffmpeg.dll containing appended encrypted payload data and logic to retrieve additional encoded content from attacker-controlled infrastructure, including GitHub raw content paths. On macOS, the trojanized component was libffmpeg.dylib. The malicious ffmpeg library remained functional while executing added code, used a manifest/timestamp-based delay mechanism of up to roughly 28 days before contacting external infrastructure, and ultimately delivered follow-on payloads including a browser-targeting infostealer. The issue was exploited in the wild in March 2023.

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exposure to the trojanized 3CX DesktopApp results in execution of attacker-supplied code under the context of the user running the application. The compromise can provide an initial foothold on affected Windows and macOS systems, enable command-and-control communications, retrieval and execution of additional payloads, theft of browser-resident data, and broader follow-on compromise. Reporting cited in the provided content notes potential unauthorized access, code execution, data exfiltration, and further malware propagation. Because the malicious software was distributed as a trusted signed update, the impact extends beyond a single host to enterprise environments that deployed the affected versions through normal software update channels.

Mitigation

If you can’t patch tonight, do this now.

Until clean software is confirmed, block or remove the 3CX DesktopApp from affected endpoints and use the browser-based PWA client as an alternative. Monitor for execution of 3CXDesktopApp.exe with vulnerable file versions and for DNS/network connections to known 3CX campaign IOC domains. Block known malicious domains and public-hosting retrieval paths used by the malware. Validate software provenance and code-signing changes, and increase scrutiny of signed third-party software updates. On potentially affected hosts, review for persistence artifacts and files noted in reporting, including Windows ffmpeg.dll anomalies and macOS artifacts such as ~/.session-lock, ~/.main_storage, and UpdateAgent-related paths under ~/Library/Application Support/3CX Desktop App/.

Remediation

Patch, then assume compromise.

Remove affected 3CX DesktopApp versions from all systems. Specifically replace Windows versions 18.12.407 and 18.12.416 and macOS versions 18.11.1213, 18.12.402, 18.12.407, and 18.12.416 with clean vendor-provided builds signed with the replacement certificate. 3CX recommended uninstalling and reinstalling the application and temporarily using the browser-based PWA client while clean desktop builds were being issued. Organizations should also hunt for indicators of compromise associated with the campaign, including suspicious DNS lookups and known malicious domains, inspect systems for malicious 3CX-bundled ffmpeg components, and investigate for follow-on payloads and credential theft on hosts where affected versions executed.
PUBLIC EXPLOITS

Exploits

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VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType
3cx3cxapplication

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What this page doesn’t show

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Exposure mapping

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Threat actor evidence8

Every observed campaign linking this CVE to a named adversary.

Associated malware

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity2

Community discussion across Reddit, Mastodon, and other social sources.