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.
ConnectWise patches critical ScreenConnect authentication failure after five days
ConnectWise patched ScreenConnect flaw CVE-2026-84869 five days after warning files could be transferred and executed via active sessions without authorization.
ConnectWise released ScreenConnect client version 26.6.5 and later to fix CVE-2026-84869, an authentication failure in ConnectWise Remote Access allowing unauthorized file transfer and execution through active remote sessions. The company warned customers on September 3 and advised admins to remove the TransferFiles permission from users with open sessions as an interim mitigation. The advisory does not state that exploitation has been observed.
ConnectWise security advisory (AV26-903)
ConnectWise patches ScreenConnect CVE-2026-84869, reported exploited in the wild; administrators should update to 26.6.5.
ConnectWise shipped ScreenConnect 26.6.5 to fix a vulnerability tracked as CVE-2026-84869 affecting versions prior to 26.6.5. Open-source reporting indicates the flaw is being exploited in the wild. The Canadian Centre for Cyber Security issued advisory AV26-903 urging users and administrators to apply the patch.
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.
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.
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.
CISA Adds Three Known Exploited Vulnerabilities to Catalog
CISA added three actively exploited vulnerabilities — two JFrog Artifactory and one ConnectWise ScreenConnect — to its KEV Catalog.
CISA added CVE-2026-42016 (JFrog Artifactory incorrect authorization), CVE-2026-42018 (JFrog Artifactory improper authentication), and CVE-2026-84869 (ConnectWise ScreenConnect improper privilege management and missing authorization) to the Known Exploited Vulnerabilities Catalog based on evidence of active exploitation. BOD 26-04 requires Federal Civilian Executive Branch agencies to prioritize rapid remediation of such high-risk vulnerabilities on publicly exposed assets and to check for prior compromise. CISA urges all organizations to adopt risk-based vulnerability management and prioritize KEV remediation.
Risky Bulletin: BEC campaign steals €35 million from French notaries
Hackers stole over €35 million from 500+ French notary offices in a four-year BEC campaign; ANSSI spent two years helping evict the attackers.
A business email compromise campaign breached more than 500 French notary offices — about 7% of all French notaries per the Conseil Supérieur du Notariat — over four years, stealing more than €35 million by phishing initial access and silently modifying wire transfer details. France's cybersecurity agency ANSSI worked for two years behind the scenes to help notaries remove the persistent attackers, who had deep access; officials also feared hackers could issue fake notarized acts such as marriage certificates or forged real estate deals. No forged documents have been found so far, but notaries have added two-factor authentication and in-person requirements for banking details, and banks added extra checks in 2024. The newsletter also notes other incidents, including a $320 million Bitcoin extraction from Blockstream's Liquid Network and a JetBrains Cadence breach via TeamCity servers.
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.
Week in review: 5 free CISA resources, surviving a DDoS attack, Google to make Cobalt Strike useless
Acronis Patches Exploited Vulnerability in cPanel Backup Plugin
Acronis urgently patched CVE-2026-87886 (CVSS 7.8), insecure file permissions enabling privilege escalation, exploited in targeted attacks on cPanel & WHM backups.
Acronis released urgent patches for CVE-2026-87886 (CVSS 7.8), insecure file permissions in the Backup plugin for cPanel & WHM and the Backup extension for Plesk that allow attackers to gain elevated privileges. Exploitation has been detected in the wild in limited, targeted attacks against the cPanel & WHM plugin, but not against the Plesk extension. All Linux versions of the plugin before build 1.9.3.1021 and the Plesk extension before build 1.8.11.638 are affected; Acronis urges immediate updates and has not shared technical details.
Hacked HBO Max Reddit Account Used for Malware Delivery via ClickFix Attack
Attackers hijacked HBO Max's verified Reddit account to push 108 malicious ads delivering AMOS and Amatera infostealers via ClickFix prompts.
Threat actors compromised the official u/hbomax Reddit account and ran 108 malicious ads over 48 hours in a campaign tracked as PasteSwitch, directing users to a fake hbomaxx[.]us site. ClickFix prompts tricked macOS users into running curl | zsh payloads (MacSync, AMOS Helper, fake wallets) and Windows users into executing MSHTA/PowerShell delivering Amatera Stealer. AnimateClipper and ZigClipper clipboard hijackers swapped cryptocurrency addresses using a blockchain-hosted C&C active since early 2026. Reddit suspended the ads after notification.
More than 200 victims of Medusa ransomware identified over the last year, CISA says
CISA and FBI update Medusa ransomware advisory, reporting more than 500 total victims and warning the gang operationalizes newly disclosed exploits within 24 hours.
CISA and the FBI updated their March 2025 advisory, stating Medusa actors had hit more than 500 victims as of April 2026, up from 300 in 2025, with a focus on healthcare and critical infrastructure. The agencies say Medusa rapidly adopts newly announced exploits, sometimes using them up to a week before public vulnerability disclosure, but does not develop its own zero-days, preferring access obtained from unknown sources. The gang moved to an affiliate model in 2023, offers up to $1 million for exclusive initial access brokers, and uses credential stealers plus legitimate remote access tools including AnyDesk, Atera, ConnectWise and Splashtop. No new victims have appeared on its leak site since April, after the shutdown of the University of Mississippi Medical Center drew significant law enforcement attention.