Threat Brief: 3CXDesktopApp Supply Chain Attack (Updated)
Trojanized 3CXDesktopApp installers for Windows and macOS loaded RC4-encrypted shellcode delivering a backdoor to hundreds of thousands of 3CX users.
Threat actors compromised the 3CXDesktopApp build process, adding malicious libraries (ffmpeg.dll, d3dcompiler_47.dll) to installers downloaded from the developer's website. The Windows MSI loader decrypts embedded shellcode with RC4, sleeps for a random 1-4 weeks, then beacons to C2 hidden in icon files on GitHub. Unit 42 fingerprinted 247,277 IPs across 199 countries using 3CX applications and blocked shellcode execution at 127 Cortex XDR customers between March 9-30, 2023.
U.S. CISA adds Apple macOS, Microsoft SharePoint, Broadcom VMware vCenter, and Microsoft IKE flaws to its Known Exploited Vulnerabilities catalog
CISA adds actively exploited flaws in Microsoft IKE, SharePoint, VMware vCenter, and macOS Screen Sharing to KEV catalog, due August 21.
CISA added four vulnerabilities to its Known Exploited Vulnerabilities catalog: CVE-2026-33824 (Windows IKE remote code execution, CVSS 9.8), CVE-2026-55040 (SharePoint JWT authentication bypass, CVSS 9.1), CVE-2026-59310 (VMware vCenter Syslog path traversal, CVSS 9.8), and CVE-2026-65400 (macOS Screen Sharing improper authentication). The SharePoint flaw combines four weaknesses including alg:none JWT forging to impersonate any user, with Defused researchers observing attackers using Rapid7's PoC against honeypots. The Dutch NCSC confirmed active exploitation of the macOS Screen Sharing flaw on August 15, 2026. Federal agencies must patch by August 21, 2026.
⚡ Weekly Recap: VMware Exploits, Windows 0-Day, MCP Attacks, Browser Hijacks and More
Weekly recap: suspected China-nexus APT exploited VMware vCenter CVE-2026-59310, Lazarus used Windows zero-day CVE-2026-68820, and macOS flaw dropped Monero miners.
The week's top stories included a suspected China-nexus APT exploiting VMware vCenter CVE-2026-59310 (CVSS 9.8), a directory-traversal flaw enabling arbitrary code execution, with backdoors, reverse SSH and Babuk-derived ransomware deployed, per QUIRSO. NCSC-NL reported active exploitation of macOS Screen Sharing flaw CVE-2026-65400 (CVSS 9.8) to install Monero miners on systems with port 5900 exposed. Lazarus Group exploited Windows zero-day CVE-2026-68820 (CVSS 7.0) in Operation Dream Job, delivering ForestTiger and Troy backdoors to defense and aerospace targets. GeoServer patched a critical SQL injection flaw exploited within hours of disclosure, and Jamf analyzed the new Amnesia Stealer for macOS with live browser control.
HBO Max Reddit Account Hijacked to Spread PasteSwitch ClickFix Malware
Hijacked HBO Max verified Reddit account ran 108 ClickFix malvertising ads delivering AMOS and Amatera stealers plus crypto clippers to macOS and Windows users.
Threat actors hijacked HBO Max's verified Reddit account (u/hbomax) to run 108 malicious ClickFix ads over 48 hours in a campaign tracked as PasteSwitch, researched by Hudson Rock and ADAMnetworks. macOS victims were served curl | zsh chains deploying MacSync and Atomic macOS Stealer (AMOS), which harvest browser credentials, Telegram data, Apple Notes, and macOS passwords, while fake Ledger, Trezor, and Exodus apps targeted BIP39 seed phrases. Windows users received an InstallFix chain using an MP3/HTA polyglot with mshta and PowerShell, scheduled-task persistence, AMSI disabling, and in-memory Amatera Stealer that hid C2 traffic (77.91.65.13:443) behind a facebook.com TLS SNI. AnimateClipper and ZigClipper components swapped copied crypto wallet addresses and used Binance Smart Chain contracts as mutable C2 dead drops; Reddit paused the ads and the initial access path remains undisclosed.
CISA Warns of Apple macOS Vulnerability Exploited in Attack (CVE-2026-65400)
CISA added actively exploited macOS flaw CVE-2026-65400 to its KEV catalog, affecting Tahoe, Sequoia, and Sonoma, with a patch deadline of August 21, 2026.
CISA acknowledged active exploitation of CVE-2026-65400, an authentication flaw affecting macOS Tahoe, Sequoia, and Sonoma, and added it to the Known Exploited Vulnerabilities Catalog. The vulnerability was discovered and reported to Apple by Alfredo Pesoli via Bynario Atlas. The remediation deadline is August 21, 2026.
Attackers exploit patched macOS Screen Sharing flaw to deploy cryptominer
Attackers actively exploit patched macOS Screen Sharing bug CVE-2026-65400 on systems with port 5900 exposed, gaining root to install a Monero cryptominer.
The Netherlands' National Cyber Security Centre (NCSC) reports active exploitation of CVE-2026-65400, an authentication flaw in macOS Screen Sharing that lets attackers authenticate without valid login credentials. Apple patched the issue in macOS Sequoia 15.7.9, Sonoma 14.8.9 and Tahoe 26.6.1, and the NCSC escalated its advisory on August 12 after proof-of-concept code went public and reports arrived of attacks on internet-exposed systems. In every reported case attackers obtained root access and installed a Monero crypto miner; users who cannot patch immediately are advised to disable Screen Sharing.