ZeroHour

Search: “rogue ScreenConnect client”

28 stories

Smart search ranks by meaning as well as keywords (one row per story, last 45 days).

ConnectWise Patches ScreenConnect Vulnerability Exploited in Worm-Like Attacks

ConnectWise patched critical ScreenConnect flaw CVE-2026-84869 (CVSS 9.9) exploited since August 20 in worm-like attacks; CISA added it to KEV.

ConnectWise released urgent patches for CVE-2026-84869 (CVSS 9.9), a missing authorization and improper privilege management flaw in ScreenConnect allowing file transfer and execution through active remote sessions without host confirmation. Huntress reported in-the-wild exploitation since August 20, with attackers using rogue ScreenConnect clients to push four VBScript files for persistence and worm-like propagation to other ScreenConnect clients. The flaw is fixed in ScreenConnect 26.6.5, with disabling the TransferFiles permission as a temporary mitigation. CISA added the CVE to its KEV catalog, requiring federal agencies to patch within three days under BOD 26-04.

SecurityWeekupdated · 48m agofirst · 2d agoExploit / PoC in the wild 4 sourcesCVE-2026-848691

Attackers use rogue ScreenConnect clients to spread malware

Attackers deploy rogue ScreenConnect clients that spread VBScript malware to newly connected machines while ConnectWise patches a file-transfer flaw.

ConnectWise confirmed a file transfer flaw in ScreenConnect affecting both Cloud and On-Premise deployments, with a CVE identifier and official fix promised within the week; administrators can mitigate immediately by disabling TransferFiles (or TransferFilesInSession) in each role. Huntress documented incidents where social engineering installs rogue ScreenConnect clients that spawn Windows Script Host processes running four VBScript files (1.vbs-4.vbs), add a WindowsServiceHost registry Run key, and propagate to newly connected endpoints. Payloads enabled host profiling, persistence, additional ScreenConnect installs, tunneling, security-control changes, and cryptocurrency mining. ConnectWise has not confirmed a technical link between the flaw and this campaign.

Help Net Security · 9d agoExploit / PoC in the wild

Rogue ScreenConnect Clients Spread Four-Stage VBScript Chain to Newly Connected Hosts

Huntress says rogue ScreenConnect clients spread a four-stage VBScript chain delivering backdoors, privilege-escalation tools, or an XMRig miner to newly connected hosts.

Huntress identified three unrelated August 2026 incidents using a Quick Assist tech-support scam, a phishing-delivered MSI installer, and a fake Geek Squad refund form to install rogue ScreenConnect clients. Each client repeatedly spawned wscript.exe to run 1.vbs through 4.vbs, which profiled the host, enumerated installed security products, and downloaded stage-specific payloads from Dropbox. Depending on detected state, payloads included a user-level ScreenConnect backdoor, UAC-bypass privilege escalation tooling, or tunneling utilities with an XMRig cryptocurrency miner. Infected clients re-infected newly connected hosts, creating worm-like propagation, and ConnectWise issued an advisory about affected file transfer behavior in ScreenConnect.

The Hacker News · 9d agoMalware in the wild

Modified ScreenConnect Clients Used in Worm-Like Campaign

Huntress warns of worm-like attacks using modified ScreenConnect clients to spread VBScript payloads; ConnectWise issued an advisory.

Campaigns starting in late August use social engineering, including Quick Assist abuse, to install rogue ScreenConnect clients that spawn wscript.exe and deploy four VBScript files for reconnaissance, staging, and PowerShell execution. The attackers persist via User Run Keys, attempt UAC bypass, install UltraViewer, and propagate the VBScript chain to other connected ScreenConnect endpoints. ConnectWise published an advisory about a file transfer behavior issue affecting cloud and on-premises ScreenConnect, with a CVE identifier and fix expected within a week; it recommends disabling file transfer meanwhile.

SecurityWeek · 9d agoExploit / PoC in the wild

Phishing Attacks Serve Browser-in-the-Browser Pages, Rogue RMM Persistence

Phishing emails with browser-in-the-browser fake Adobe pages trick users into installing rogue ScreenConnect clients granting persistent remote access.

Huntress SOC investigated two August incidents where phishing links led to fake CAPTCHA checks and Adobe PDF Reader lures rendered as browser-in-the-browser (BiTB) pages spoofing legitimate domains like get.adobe.com. Victims downloaded what they believed was Acrobat Reader but actually installed ScreenConnect.ClientSetup.exe from attacker infrastructure, yielding two rogue ScreenConnect clients with service-based persistence. The attacker used cmd.exe and curl to stage a second client connecting to 144.172.115.59, leveraged a ScreenConnect Trial Relay domain for stealth, and ran HideCursor.exe as a defense-evasion binary. Incident 2 arrived via AT&T Office@Hand (RingCentral), with both chains stopped before broader impact.

Huntress · 6d agoPhishing & fraud in the wild

Rogue ScreenConnect Installations Across Unrelated Hosts Suggest Worm-Like Activity

Huntress observed rogue ScreenConnect deployments with worm-like VBScript propagation across unrelated organizations, prompting a ConnectWise advisory on file transfer behavior.

Huntress identified multiple incidents in late August 2026 where social engineering led to rogue ScreenConnect remote access clients deployed on victim machines, which then spawned wscript.exe to run four VBScript payloads (1.vbs through 4.vbs) for profiling, telemetry collection, and persistence via a WindowsServiceHost Run key. Modified ScreenConnect clients propagated the VBScript chain to connected endpoints, creating worm-like spread. ConnectWise published an advisory on September 3, 2026, confirming an issue affecting file transfer behavior in both cloud and on-premises ScreenConnect deployments, with a CVE and fix expected within the week; partners were advised to review and disable TransferFiles permissions in the interim.

Huntress · 13d agoExploit / PoC in the wild1

U.S. CISA adds GitLab, JFrog Artifactory, and ConnectWise ScreenConnect flaws to its Known Exploited Vulnerabilities catalog

CISA added four actively exploited GitLab, JFrog Artifactory, and ConnectWise ScreenConnect flaws to the KEV catalog with imminent deadlines.

CISA added CVE-2026-42016 and CVE-2026-42018 (JFrog Artifactory), CVE-2026-84869 (ConnectWise ScreenConnect), and CVE-2026-85706 (GitLab, CVSS 10.0) to its KEV catalog. Artifactory flaws are being chained with CVE-2026-82329 in attacks observed August 15 to September 8, taking over self-hosted servers, creating persistent administrator accounts, and installing backdoors. ScreenConnect CVE-2026-84869 allows unauthorized file transfer and execution during remote sessions, linked by Huntress to malicious VBScript deliveries, and is fixed in version 26.6.5. GitLab's repository commits API path traversal exposes SSH keys, database credentials, deploy tokens, and CI/CD variables, with watchTowr already observing in-the-wild probes. Federal agencies must patch GitLab and ScreenConnect flaws by September 14, 2026, and Artifactory flaws by September 25, 2026.

2026-010: Critical Vulnerabilities in Citrix NetScaler ADC and NetScaler Gateway

Citrix patched NetScaler ADC/Gateway: auth bypass CVE-2026-19490 (CVSS 9.3) on Gateway/AAA configs and memory overflow CVE-2026-19489 (CVSS 8.8) requiring SIP ALG.

On 19 August 2026 Citrix published an advisory fixing two critical-severity issues in NetScaler ADC and NetScaler Gateway versions 14.1 before 14.1-73.32 and 13.1 before 13.1-63.21, plus FIPS/NDcPP builds. CVE-2026-19490 (CVSS 9.3) is an authentication bypass via alternate path, exploitable when the appliance is configured as a Gateway (SSL VPN, ICA Proxy, CVPN, RDP Proxy) or AAA virtual server, with a SAML action condition on newer builds. CVE-2026-19489 (CVSS 8.8) is a memory overflow causing unpredictable behaviour or denial of service, requiring SIP ALG enabled on a Large Scale NAT group. CERT-EU recommends applying updated builds as soon as possible.

CERT-EU Advisoriesupdated · 11d agofirst · 28d agoVulnerability 3 sourcesCVE-2026-19489CVE-2026-19490

ConnectWise warns of new ScreenConnect flaw without patch

ConnectWise warns of an unpatched ScreenConnect flaw affecting file transfer in support sessions and shares interim mitigations for MSPs.

ConnectWise disclosed a new ScreenConnect Remote Access vulnerability affecting file transfer behavior in both cloud and on-premises deployments; no CVE ID or patch is available yet, with a fix planned later this week. The vendor published temporary mitigation steps that remove TransferFiles permissions from session groups across all roles. Shadowserver tracks nearly 6,000 internet-exposed ScreenConnect instances. Previous ScreenConnect flaws, including CVE-2024-1709, were exploited by ransomware gangs and North Korea's Kimsuky, and three ScreenConnect vulnerabilities are on CISA's actively exploited catalog.

Week in review: Linux rootkit deployed on F5 BIG-IP APM devices, Cisco FMC bugs exploited

Weekly roundup: Cisco FMC and N-able N-central zero-days exploited in the wild, MikroTik RouterOS hijacks, Microsoft Patch Tuesday ships two exploited zero-days.

State-sponsored and financially-motivated attackers are actively exploiting CVE-2026-20079, a critical authentication bypass in Cisco Secure Firewall Management Center (FMC), alongside CVE-2026-20316. N-able issued an emergency hotfix for CVE-2026-86218, a critical pre-auth RCE in the N-central RMM platform exploited in the wild. CERT Polska disclosed six RouterOS vulnerabilities being chained to hijack internet-exposed MikroTik devices. Microsoft's September 2026 Patch Tuesday shipped a record patch count including two zero-days, while roughly 67,000 Trezor customers faced phishing after a shipping-partner breach and researchers privately disclosed a zero-click WeChat worm to Tencent.

Help Net Security · 3d agoExploit / PoC in the wildCVE-2026-20079CVE-2026-20316CVE-2026-862182· 1 read

ThreatsDay: CEO Phishing Kits, 5K Dropbox Account Hacks, OAuth Traps + 17 More Stories

Microsoft warns of Teams IT-impersonation intrusions deploying Node.js implants; Spring Ring vishing hit 150+ employees across 10 companies; The Gentlemen ransomware claims 683 victims.

Microsoft warned of a human-operated campaign abusing Teams external collaboration to impersonate IT help desk staff, deploy malicious MSI packages staging Node.js runtimes and obfuscated JavaScript implants, then pivot to domain controllers over WinRM. Unit 42 documented the Spring Ring vishing operation targeting over 150 employees across at least 10 companies using 26 attacker identities, including an NTLM relay variant against domain controllers. Sophos reported The Gentlemen ransomware (Gold Sherwood) reached 683 total victims by end of July 2026, adding 169 in July, with a playbook using BYOVD-based EDR killers and backup tampering. Group-IB found the Outsider phishing-as-a-service platform created 700+ new phishing pages within a month despite law enforcement takedowns.

The Hacker News · 12d agoThreat actor in the wild1

ShieldBreak: New Windows Zero-Day Bypasses Microsoft’s RoguePlanet Patch

Researcher Chaotic Eclipse published a PoC bypassing Microsoft's CVE-2026-50656 Defender patch, enabling SYSTEM-level code execution on fully patched Windows systems.

Security researcher Chaotic Eclipse released a proof-of-concept for ShieldBreak, a Microsoft Defender zero-day that fully bypasses the patch for CVE-2026-50656 (RoguePlanet), a race condition in the Malware Protection Engine (mpengine.dll) allowing SYSTEM-level code execution. The PoC was tested on Windows 11 25H2 and Windows Server 2025 with a 100% success rate, and Windows 10 is also vulnerable though not supported by the PoC; the flaw may also leak 8 bytes of memory. Microsoft's MSRC had criticized the researcher's repeated uncoordinated disclosures, including YellowKey (BitLocker bypass), GreenPlasma, and LegacyHive (User Profile Service LPE).

Security Affairs · Aug 12, 2026Exploit / PoCCVE-2026-50656

Attackers Use Multi-Hop Google Redirects for Phishing Campaign

Threat actors chain multiple legitimate Google service redirects to evade detection and deliver credential harvesting or ScreenConnect remote access tooling.

Threat actors are abusing multiple legitimate Google services to build multi-hop redirect chains that obscure the final destination and bypass reputation-based filtering. The campaign culminates in credential harvesting pages or silent installation of the ScreenConnect remote access tool. Defenders should watch for links that traverse trusted Google domains before landing on malicious endpoints.

Dark Reading · 7d agoPhishing & fraud in the wild

Exploits in the Wild for Citrix ADC and Citrix Gateway Directory Traversal Vulnerability CVE-2019

Unit 42 confirmed in-the-wild exploitation of CVE-2019-19781, a critical Citrix ADC/Gateway directory traversal flaw enabling unauthenticated file access and RCE.

CVE-2019-19781, a CVSS 9.8 directory traversal vulnerability, affects all supported versions of Citrix ADC and Citrix Gateway. Unit 42 captured multiple exploitation attempts in the wild and identified scanning activity from roughly 700 Shodan-exposed hosts. The flaw stems from improper pathname handling in Apache, allowing unauthenticated attackers to read sensitive files like smb.conf or achieve remote code execution via crafted XML. Palo Alto Networks released Threat Prevention signatures 57497 and 57570 on January 7, 2020, while Citrix published advisories CTX267027 and CTX267679 with responder policy mitigations pending a late-January patch.

Palo Alto Unit 42 · 29d agoExploit / PoC in the wildCVE-2019-19781

Jellyfin 12.0 security fixes arrive alongside the removal of legacy client logins

Jellyfin 12.0 ships security fixes for path traversal, first-run setup bypass, unsafe plugin names, and web client XSS, plus removal of legacy login paths.

Jellyfin 12.0 blocks requests built to reach files outside served folders, prevents setup-wizard re-runs on misconfigured servers, rejects unsafe plugin package names, and fixes web client cross-site scripting. The project published no CVE identifiers or severity ratings for the fixes. The release also drops legacy /emby/ and /mediabrowser/ endpoints, targets .NET 10, and breaks 10.11-era third-party plugins.

Help Net Security · 8d agoVulnerability

Chaotic Eclipse Released ShieldCrash, A PoC For Microsoft Defender Zero-Day

Researcher Chaotic Eclipse released ShieldCrash, a PoC showing Microsoft Defender's CVE-2026-69414 patch is incomplete, enabling arbitrary file reads as SYSTEM.

Security researcher Chaotic Eclipse published ShieldCrash, a proof-of-concept exploit for the Microsoft Malware Protection Engine privilege escalation vulnerability CVE-2026-69414 (ShieldBreak). The PoC performs arbitrary file reads with SYSTEM privileges on all supported Windows versions, including systems running the September 2026 security updates and Malware Protection Engine version 1.1.26080.3. The researcher claims Microsoft's patch fixed several exploit paths but missed a specific condition that still enables the attack. His recent releases also include zero-day PoCs targeting Nvidia, Kaspersky, Avast, and CrowdStrike Falcon.

ZDI-26-588: Fabric.js loadFromJSON Server-Side Request Forgery Vulnerability

ZDI disclosed a server-side request forgery in Fabric.js loadFromJSON (CVE-2026-19504) that can leak sensitive information from affected implementations.

Zero Day Initiative advisory ZDI-26-588 describes a server-side request forgery vulnerability in the Fabric.js canvas library's loadFromJSON function. Exploitation requires interaction with the library and attack vectors vary by implementation, potentially exposing sensitive information. The issue is rated 4.0 on the CVSS scale and tracked as CVE-2026-19504. The advisory does not report exploitation in the wild.

Windows Remote Desktop Client Vulnerability Allows Attackers to Execute Remote Code

Microsoft patched CVE-2026-69485, an 8.8 CVSS RCE flaw in the Windows Remote Desktop Client affecting Windows 10/11 and Server 2016-2025.

Microsoft's September 2026 updates fix CVE-2026-69485, an Important-rated remote code execution vulnerability (CVSS 3.1: 8.8, temporal 7.7) in the Windows Remote Desktop Client caused by use of an uninitialized resource. An authenticated attacker with low privileges could send a specially crafted network request to execute code on an affected server, with no user interaction required. Microsoft says the flaw was not publicly disclosed before patching and rates exploitation as 'Less Likely' with no evidence of active exploitation. Affected products span Windows Server 2016, 2019, 2022 and 2025 and Windows 10 (1607-22H2) and Windows 11 (23H2-26H1), with fixes delivered via KBs including KB5123099, KB5122876 and KB5122882.

New ‘ShieldCrash’ Zero-Day Exploit Targets Microsoft Defender

Researcher Nightmare Eclipse released ShieldCrash, a Microsoft Defender zero-day PoC bypassing ShieldBreak patches to gain System privileges on Windows.

The researcher known as Nightmare Eclipse released a PoC zero-day exploit dubbed ShieldCrash against Microsoft Defender on fully patched Windows systems. The exploit grants arbitrary file read with System privileges and can be used to drop the SAM database. It bypasses Microsoft's September 3 fixes for ShieldBreak (CVE-2026-69414), which itself bypassed patches for the RoguePlanet race condition (CVE-2026-50656). Microsoft has been contacted for comment and has not yet responded.

SecurityWeekupdated · 5d agofirst · 6d agoExploit / PoC 4 sourcesCVE-2026-50656CVE-2026-694141

Researcher Drops New Microsoft Defender PoC Showing ShieldBreak Patch Can Be Bypassed

Researcher Chaotic Eclipse released a PoC showing CVE-2026-69414's patch is bypassable, allowing arbitrary file reads as SYSTEM on current Windows.

The researcher known as Chaotic Eclipse published a proof-of-concept for a zero-day in Microsoft Defender, dubbed ShieldCrash, assessed as a patch bypass for ShieldBreak (CVE-2026-69414, CVSS 7.8). The PoC demonstrates an arbitrary file read as SYSTEM with the latest Windows installed, and all supported desktop versions are said to be impacted. Microsoft patched the original issue in Microsoft Malware Protection Engine 1.1.26080.3, which updates automatically. The same researcher recently released PoCs for flaws in CrowdStrike Falcon Sensor, Kaspersky, Avast Antivirus and NVIDIA.

The Hacker News · 7d agoExploit / PoCCVE-2026-694141

Nintendo Switch QR Code Vulnerability Lets Nearby Attackers Execute Unauthorized Code

Nintendo patched CVE-2026-82079 (CVSS 8.4), a stack buffer overflow in Switch local wireless pairing enabling nearby attackers to execute code.

Nintendo Switch system update 23.0.0 fixes CVE-2026-82079, a stack-based buffer overflow in local wireless networking abused via the QR code sharing process, including Album's 'Send to Smartphone' and Mario Kart Live pairing. A nearby attacker who scans the displayed QR code can send crafted traffic and use return-oriented programming to achieve arbitrary code execution. CVSS scores are 8.4 (v3.1) and 7.0 (v4.0), both rated High. No in-the-wild exploitation is reported and Switch 2 systems are not affected.

CVE-2026-19490: Critical Vulnerability Affecting Citrix NetScaler ADC and NetScaler Gateway

CVE-2026-19490 is a critical unauthenticated authentication bypass in Citrix NetScaler ADC and Gateway, remotely exploitable without user interaction.

An advisory published August 19, 2026 describes CVE-2026-19490, a critical authentication bypass affecting Citrix NetScaler ADC and NetScaler Gateway. The flaw carries a CVSS v4.0 base score of 9.3 and is remotely exploitable by unauthenticated attackers over the network without user interaction or elevated privileges. NetScaler ADC and Gateway are widely deployed enterprise products positioned at or near the network perimeter, providing load balancing, SSL/TLS offloading, and secure remote access. The text does not state whether exploitation has been observed in the wild.

Rapid7 Blog · 27d agoVulnerabilityCVE-2026-194901

Previously patched Citrix NetScaler flaw exploited in the wild (CVE-2026-8452)

Actively exploited Citrix NetScaler flaw CVE-2026-8452, patched in June, now added to CISA KEV; attackers deploy web shells and run discovery commands.

CISA added CVE-2026-8452, a memory overflow vulnerability in Citrix NetScaler ADC/Gateway, to its Known Exploited Vulnerabilities catalog on August 26, 2026, giving federal agencies until August 29 to remediate. Citrix disclosed and patched the flaw on June 30, 2026 in versions 14.1-72.61, 13.1-63.18, and 13.1-37.272. watchTowr Labs found the flaw can be chained into unauthenticated remote code execution and released a PoC on August 14. Previdian and Defused reported exploitation with web shells named x.php and z.php from at least three unique source IPs.

Help Net Security · 20d agoExploit / PoC in the wildCVE-2026-8452CVE-2015-3246CVE-2015-5287+3 CVEs

Dell Secure Connect Gateway Vulnerabilities Allow Hackers to Gain Unauthorized Access

Dell patches three critical flaws (CVSS up to 9.8) in Secure Connect Gateway 5.0 enabling admin token replay, unauthenticated RCE, and root escalation.

Dell disclosed three critical vulnerabilities in Secure Connect Gateway 5.0 appliance and application deployments. CVE-2026-80172 (CVSS 9.8) lets unauthenticated attackers replay captured requests, which lack nonce validation and time limits, to repeatedly mint administrator access and refresh tokens. CVE-2026-61410 (9.4) is a missing-authorization flaw enabling unauthenticated remote command execution, and CVE-2026-80238 (9.3) is an exposed Docker socket allowing local privilege escalation to root and container escape. Fixes ship in appliance 5.36.00.16 and application 5.36.00.00.

Google Patches Pixel Modem Flaw Amid Signs of Limited Targeted Exploitationnew

Google's September Pixel update patches CVE-2026-58704, a high-severity cellular modem privilege escalation flaw showing signs of limited targeted exploitation.

Google disclosed CVE-2026-58704 (CVSS 8.0), a privilege escalation flaw in the Pixel Cellular Modem caused by a logic error permitting proximal/adjacent privilege escalation with no user interaction or extra privileges needed. Google acknowledged indications the flaw may be under limited, targeted exploitation but did not identify the threat actor. The September 2026 Pixel update fixes 109 additional flaws, including 46 critical-severity issues in components such as BigOcean, Bootloader, IMS, and Trusted Execution Environment, plus two high-severity kernel privilege escalation bugs (CVE-2026-56914, CVE-2026-58773). Security patch level 2026-09-05 or later resolves all identified flaws.

The Coding-Agent Trap: When a "Free" LLM Endpoint Is the Adversary, (Mon, Aug 31st)

A SANS honeypot caught a real coding-agent session routed to a rogue "free" LLM endpoint, exposing a Windows user's transcript and tool outputs.

A SANS analyst describes how an internet-exposed inference honeypot was discovered, relabeled with sought-after model names like DeepSeek, and enrolled in infrastructure serving "free" LLM backends. On 2026-08-30 an opencode terminal coding agent sent an 88-message, 224 KB transcript 210 times in 91 seconds via a China Unicom relay, exposing directory listings, tool outputs and read file portions. The analyst frames tool-enabled agents treating model endpoints as trusted control planes as a novel risk — a "rogue model endpoint" that could request tool executions on the user's machine.

SANS Internet Storm Center · 15d agoAI safety & security1