Cybersecurity Brief – 2026-09-23

Wed, 23 Sep 2026 00:00:00 +0000

Major Incidents or Breaches

The ShinyHunters cyber extortion group claims to have breached the US Federal Bureau of Investigation, stealing data on current and former employees and job applicants. The group states it exploited a zero-day vulnerability in Oracle PeopleSoft to access internal services and exfiltrate sensitive data. ShinyHunters is demanding the FBI retract a report describing its tactics and threatens to leak the stolen information if demands are not met ^[10]^[24]^[50]^[52].
Threat actors stole 170 private repositories from cybersecurity firm CrowdSec by leveraging an OAuth token obtained through the TanStack npm supply chain attack on a former employee’s computer ^[35].
Sweden’s data privacy regulator fined IT provider Miljödata $183,000 for insufficient security measures that led to a breach in August 2025, affecting 2.2 million individuals ^[22].

Newly Discovered Vulnerabilities

F5 disclosed and patched a critical zero-day vulnerability (CVE-2026-94127) in BIG-IP Access Policy Manager (APM) that allows unauthenticated attackers to execute remote code on affected systems. The flaw was actively exploited in attacks targeting OAuth servers ^[7]^[20]^[49].
Check Point released emergency fixes for a zero-day vulnerability (CVE-2026-93616) in its Security Management Server, which allowed attackers in targeted attacks to upload and execute arbitrary scripts ^[11]^[27]^[51].
Arista Networks patched a zero-day vulnerability in VeloCloud Orchestrator (VCO) On-Prem deployments, which was being actively exploited to allow remote attackers access to privileged internal functionality ^[17]^[48].
A new cPanel flaw in the CalDAV and CardDAV services enables any hosting account holder to execute code as root, granting full server control ^[3].
A critical vulnerability in Bifrost, an open-source AI gateway, allows unauthenticated attackers to execute arbitrary commands on the server without credentials ^[15].
A use-after-free vulnerability in the Linux kernel’s AF_UNIX socket subsystem enables container escape and host root access. An exploit has been released and the flaw remains unpatched in Ubuntu ^[6].
WordPress patched a critical flaw in its core software that allowed unauthenticated attackers to load arbitrary PHP files from outside theme folders, potentially leading to remote code execution on some servers ^[12].
Next.js disclosed a critical ImageResponse vulnerability that can lead to server code execution via crafted SVG input ^[9].
Adobe released patches for nine critical vulnerabilities in Connect and AEM Forms that could be exploited for arbitrary code execution and privilege escalation ^[43].
Google Chrome 154 patched 108 vulnerabilities, including several rated critical for memory safety and memory corruption ^[45].

Notable Threat Actor Activity

A Chinese state-linked threat actor (UTA0565) exploited a zero-day exploit chain in Google Chrome and Microsoft Windows via fake websites to deploy CLEANGULP malware, targeting victims with advanced techniques ^[8].
Chinese-speaking threat actors have been exploiting vulnerabilities in Zyxel GS1900 Smart Managed Switches and WordPress to steal sensitive government data from nearly 1,000 devices and over 18,500 records ^[23].
The EvilTokens phishing-as-a-service platform, which compromised more than 12,000 Microsoft accounts at over 10,000 organizations using AI-driven attack chains, was disrupted in a coordinated takedown by Microsoft, which seized 50 websites and disabled over 150 domains ^[14]^[28]^[33]^[44].
A malicious npm package (“tw-pkgprobe-7731”) posed as a Twilio bug-bounty probe to target developers, enabling credential exfiltration ^[13].
A new Windows malware, ClosedQuorum, uses multiple AI models (Google Gemini, DeepSeek, Qwen, Mistral) to autonomously determine post-compromise actions ^[25].
The Ryuk ransomware group member was sentenced to 24 months in prison for attacks on US companies ^[19].
Threat actors exploited a stolen OAuth token from a former employee to access CrowdSec’s private GitHub repositories ^[35].

Trends, Tools, or Tactics of Interest

An AI-assisted phishing campaign sent over one million personalized emails attempting payment diversion scams, demonstrating the growing use of AI in large-scale phishing operations ^[1].
AI is increasingly being leveraged in both attack (e.g., phishing, malware decision-making) and defense (e.g., autonomous security agents), with new tools emerging to benchmark and control AI agent performance ^[4]^[5]^[25]^[36]^[44]^[47].
Attackers with privileged access can register rogue external MFA providers to steal user passwords during legitimate login attempts ^[21].
More than 80,000 AI relay servers are being used to mask Chinese access to frontier AI models in the US, likely to facilitate model cloning ^[31].
A proof-of-concept zero-day tool, BigDiskBuster, was released that can block Microsoft Defender updates by filling available disk space ^[16].
The Cybersecurity and Infrastructure Security Agency (CISA) published guidance on deception techniques to help organizations set traps for cybercriminals ^[34].
Shadow IT remains a challenge, with tools like Wazuh recommended to improve visibility of unmanaged endpoints and unauthorized assets ^[26].
Honeywell research indicates that while 88% of OT security leaders consider their programs mature, only 21% have a complete OT asset inventory, and full autonomy in OT security remains rare ^[42].

Regulatory or Policy Developments Affecting the Security Industry

Sweden’s IMY imposed a significant fine on Miljödata for inadequate data protection, reinforcing regulatory expectations for IT service providers handling large volumes of personal data ^[22].

Sources

ShinyHunters Claims FBI Breach, Says It Stole Data on Agents and Job Applicants - thehackernews.com
ShinyHunters claims FBI hack, data theft in PeopleSoft zero-day breach - bleepingcomputer.com
ShinyHunters Claims FBI Hack, Demands Retraction of Threat Report - securityweek.com
ShinyHunters claims FBI breach was revenge for “false” report - malwarebytes.com
Shai-Hulud Attack Nips Cyber-Firm CrowdSec's GitHub Data - darkreading.com
Sweden fines Miljödata $183,000 over breach affecting 2.2 million - bleepingcomputer.com
F5 Patches Critical BIG-IP APM Zero-Day Exploited for Unauthenticated RCE on OAuth Servers - thehackernews.com
F5 patches BIG-IP APM zero-day flaw exploited in RCE attacks - bleepingcomputer.com
Critical F5 BIG-IP Vulnerability Exploited as Zero-Day - securityweek.com
Check Point Warns of Management Server Zero-Day Exploited in Targeted Attacks - thehackernews.com
Check Point warns of Management Server zero-day exploited in attacks - bleepingcomputer.com
Check Point Patches Exploited Management Server Zero-Day - securityweek.com
Arista patches actively exploited VeloCloud Orchestrator zero-day - bleepingcomputer.com
Arista Urges Immediate Patching of Exploited VCO Zero-Day - securityweek.com
New cPanel Flaw Lets a Hosting Account Run Code as Root, Take Full Server Control - thehackernews.com
Critical Bifrost AI Gateway Flaw Lets Attackers Run Commands Without Credentials - thehackernews.com
Exploit Released for Unpatched Ubuntu Linux Flaw Enabling Host-Root Container Escape - thehackernews.com
WordPress Issues Patch for Critical Flaw That Can Enable Code Execution on Some Servers - thehackernews.com
Critical Next.js ImageResponse Flaw Can Lead to Server Code Execution via Crafted SVG Input - thehackernews.com
Adobe Patches Critical Flaws in Connect, AEM Forms - securityweek.com
Chrome 154 Patches 108 Vulnerabilities - securityweek.com
Chinese Hackers Exploit Chrome-Windows Zero-Day Chain to Deploy CLEANGULP Malware - thehackernews.com
Chinese hackers exploit WordPress, Zyxel flaws to steal govt data - bleepingcomputer.com
Microsoft Takes Down EvilTokens Device-Code Phishing Service Tied to 12,000 Inbox Compromises - thehackernews.com
EvilTokens PhaaS disrupted after compromising 12,000 Microsoft accounts - bleepingcomputer.com
Microsoft Disrupts EvilTokens Device Code Phishing Service - darkreading.com
AI-Powered Phishing Platform EvilTokens Disrupted by Microsoft - securityweek.com
Malicious npm Package Poses as Twilio Bug-Bounty Probe, Can Exfiltrate Credentials - thehackernews.com
New ClosedQuorum Windows malware uses AI for attack decisions - bleepingcomputer.com
Ryuk ransomware member sentenced to 24 months in prison - bleepingcomputer.com
AI-Assisted Phishing Campaign Sent Over A Million Personalized Emails - blog.knowbe4.com
545 Hackers Tested It First. Now XRanges for AI Scores Your Security Agent - thehackernews.com
Anthropic and OpenAI Models Still Attempt Restricted Actions in Safety Tests - thehackernews.com
Amid Ongoing Rogue Incidents, Debate Over AI Safety Gets Real - darkreading.com
Outerlimit Raises $16 Million to Stop Rogue AI Agents From Causing Harm - securityweek.com
Rogue external MFA providers can steal passwords during logins - bleepingcomputer.com
Relays Are Masking Chinese Access to Frontier AI Models in the US - darkreading.com
Researcher Drops BigDiskBuster Zero-Day PoC That Blocks Microsoft Defender Updates - thehackernews.com
Deception by Design: CISA's Guide to Tricking Cybercriminals - darkreading.com
Reducing shadow IT visibility gaps with Wazuh - bleepingcomputer.com
Honeywell: OT Security Teams Embrace AI, but Autonomy Still Rare - securityweek.com

UTA0565 on DanSec Daily

Cybersecurity Brief – 2026-09-23

Major Incidents or Breaches

Newly Discovered Vulnerabilities

Notable Threat Actor Activity

Trends, Tools, or Tactics of Interest

Regulatory or Policy Developments Affecting the Security Industry

Sources