Week in review: Firmware-level Android backdoor found on tablets, Dell zero-day exploited since 2024
Weekly Cybersecurity Newsletter Bulletin – Microsoft 0-day, FortiOS, PAN-OS Flaw, Revolut Data Breach, and 20+ Stories
Weekly roundup: Microsoft patches 973 flaws including two actively exploited zero-days; FortiOS CAPWAP flaw deploys PivotC2 RAT; PAN-OS root RCE disclosed.
Microsoft's September 2026 Patch Tuesday fixed 973 vulnerabilities, including two zero-days under active exploitation: CVE-2026-85880 (Windows ALPC) and CVE-2026-81963 (Windows Update Stack), both elevation-of-privilege bugs. SOCRadar reported active exploitation of CVE-2025-25249 (CVSS 9.8) in FortiOS CAPWAP, deploying a Node.js RAT called PivotC2 that exfiltrates Exchange mailboxes to Wasabi cloud storage; 178 devices were compromised out of 30,000 scanned IPs, attributed to a Russian-speaking financially motivated group. Palo Alto disclosed CVE-2026-0310, a 9.2-rated buffer overflow enabling root code execution on PA-Series firewalls, and Fortinet disclosed CVE-2026-84393, a ZTNA certificate validation MITM flaw. Cyera also revealed CVE-2026-6471 ('PostGREShell'), a 12-year-old PostgreSQL logical-decoding flaw allowing code execution via REPLICATION-privileged accounts.
BlueMoon exploit kit turns Chrome and Windows flaws into attacks
Proofpoint documents BlueMoon exploit kit used by four espionage groups to chain Chrome V8 and Windows flaws via phishing, all now in CISA's KEV.
Proofpoint identified a shared Chrome and Windows exploit kit, BlueMoon, used by four espionage groups against Chrome on Windows within days of one another. Attacks began with phishing emails leading to web pages that exploited two Chrome V8 vulnerabilities, followed by a Windows flaw to escape browser protections and gain higher privileges. The Chrome flaws were patched in Stable on September 3 and 8, 2026, the Windows flaw was fixed in September Patch Tuesday, and all three were actively exploited and added to CISA's KEV catalog. Researchers found clues, but no conclusive evidence, that the kit was developed with AI assistance.
MikroTik patches flaws currently being exploited to take over routers
MikroTik patches six RouterOS flaws, including the actively exploited MikroTrick SSH chain (CVE-2026-67276, CVE-2026-86060) enabling unauthenticated full router takeover.
MikroTik released patches in RouterOS 7.25 beta 3, 7.24.2, 7.23.4, and 6.49.21 for six vulnerabilities found by CERT Polska, affecting the SSH server/client, bandwidth-test service, X.509 handling, and WebFig. CVE-2026-67276, an RSA public-key validation flaw in the SSH server, lets an attacker who knows a username and key modulus authenticate as that user; CVE-2026-86060 then escalates privileges to root via special-character username handling. CERT Polska confirmed attackers are exploiting the chain to take full control of RouterOS devices with SSH exposed to the internet. Shadowserver Foundation scans show over 122,500 devices with internet-reachable SSH, concentrated in Brazil, the US, and Indonesia.
Mikrotik security advisory (AV26-887)
Canada's Cyber Centre urges MikroTik RouterOS updates as CVE-2026-67276, CVE-2026-67277 and CVE-2026-86060 are reported exploited in the wild.
Canadian Centre for Cyber Security advisory AV26-887 covers MikroTik RouterOS vulnerabilities affecting versions prior to 6.49.21, 7.23.4, 7.24.2 and 7.25 beta 3. Open-source reporting indicates CVE-2026-67276, CVE-2026-67277 and CVE-2026-86060 are being exploited in the wild. The Cyber Centre urges users and administrators to review the vendor advisories and apply the necessary updates.
Attackers Hijack MikroTik Routers Through Internet-Exposed SSH Without Authentication
CERT Polska warns attackers exploit internet-exposed MikroTik SSH for unauthenticated full admin control; attacks observed since at least September 2.
CERT Polska warned on September 5 that attackers exploit MikroTik routers with internet-reachable SSH to gain full administrative control without authentication, calling the two-flaw combination 'MikroTrick'. Successful attacks date to at least September 2; no victim count or attacker identity was disclosed. MikroTik shipped fixed RouterOS releases: 6.49.21, 7.23.4 (with 7.23.5 fixing an IPv6 DHCP regression), 7.24.2, and 7.25beta3. CERT recommends immediate updates, checking for unauthorized configuration changes, and restricting SSH, WWW/WWW-SSL, and bandwidth-test services on unpatched devices.
Tracking OceanLotus’ new Downloader, KerrDown
Unit 42 identifies KerrDown, a new OceanLotus (APT32) downloader active since 2018 targeting Vietnamese speakers via malicious macros and DLL side-loading.
Unit 42 tracks KerrDown, a previously undocumented downloader family used by OceanLotus (APT32) since at least early 2018, primarily targeting Vietnam or Vietnamese-speaking individuals. Delivery uses macro-laced Microsoft Office documents embedding base64-encoded 32-bit and 64-bit DLLs, and RAR archives containing a legitimate program abused for DLL side-loading. KerrDown is dropped as main_background.png, downloads a DES-encrypted payload from a URL, and executes it directly in memory. Researchers used Jaccard-index similarity analysis to identify the new family, connect campaign samples, and infer patterns in the group's working hours and days.