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Threat Brief: Ongoing Russia and Ukraine Cyber Activity

Ukrainian government sites were defaced via OctoberCMS CVE-2021-32648 while Microsoft-attributed actor DEV-0586 deployed destructive WhisperGate malware.

Unit 42 tracks January 2022 attacks against Ukrainian government websites that were defaced or made inaccessible, which Ukraine attributed to Russia. Attackers exploited CVE-2021-32648, an account takeover flaw in OctoberCMS prior to 1.0.472, by submitting a boolean true as the password reset code to bypass validation. Separately, WhisperGate malware, attributed by Microsoft to DEV-0586, disabled Windows Defender and corrupted files across multiple Ukrainian organizations, using a ransomware-appearing first stage and an HTTPS-beaconing second stage with LOLBINs and anti-analysis techniques.

Palo Alto Unit 42 · 29d agoThreat actor in the wildCVE-2021-326481

Cybercriminals Turn GTA VI Leaks Into Malware Bait

Attackers spread fake 113GB GTA VI builds whose 50KB payload whitelists the entire C: drive in Windows Defender, alongside credential phishing and infostealer campaigns.

Researchers found that a 113GB file claiming to be a playable Grand Theft Auto VI build is 99.99% empty data hiding a tiny malicious payload that excludes the entire C:\ drive from Windows Defender and kills security software, preparing systems for follow-on attacks. Related lures include fake GTA 6 Windows installers using DLL side-loading, a fake 'GTA 6 Mobile' app redirecting to infostealer and ransomware infrastructure, and counterfeit Rockstar Social Club login pages harvesting credentials. The fakes ride genuine leak momentum from the leaker CyberLeek, and Kaspersky separately documented over 19 million attempted downloads of game-themed malware in a year, with GTA, Minecraft, and Call of Duty the most abused brands. No legitimate playable GTA VI build is circulating; the game launches November 19 on consoles.

Security Affairs · 22d agoMalware in the wild

Four REVSTEALER-Linked Modules Disable Windows Update and Defender to Run a Crypto Miner

Elastic documents four persistent REVSTEALER-linked tools (ProManager, WinUpdate, SoftManager, LockAppHost); LockAppHost disables Windows Update and Defender to run a crypto miner.

Elastic Security Labs identified four previously unreported executables tied to REVSTEALER, a commercial Windows infostealer sold since at least February 2026: ProManager, WinUpdate, SoftManager, and LockAppHost. LockAppHost abuses CMSTP for elevation, adds Microsoft Defender exclusions, disables five Windows Update services and 13 scheduled tasks, then hides a miner in legitimate Windows processes; other modules steal wallets, clipboard-swap crypto addresses, and turn victims into reverse proxies. The components share REVSTEALER tradecraft including packer, runtime function resolution, and Polygon smart-contract backup configuration (EtherHiding). Elastic's detection rule matched about 4,700 VirusTotal samples over the past year; distribution uses hijacked YouTube channels promoting game cheats and a fake 'Claude Opus 5 Free Desktop' app.

The Hacker News · 10d agoMalware 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

Mustang Panda Upgrades CoolClient With a Kernel Rootkit

Mustang Panda's updated CoolClient backdoor deploys a signed kernel driver to hide processes, files and network activity in Asian intrusions.

Kaspersky analysis shows Mustang Panda (HoneyMyte) upgraded its CoolClient espionage backdoor with a signed kernel-mode driver installed as a Windows service, communicating via IOCTL requests to hide processes, files and registry entries. In a Myanmar campaign the actor deployed PlugX first, then CoolClient via a fake Windows Defender directory and Sangfor defender.exe DLL sideloading, with scheduled task and AutoRun persistence and UAC bypass. The updated variant was observed in intrusions across Pakistan, Mongolia and Myanmar, with victims also in Russia including confirmed government entities.

Security Affairs · Aug 16, 2026Threat actor in the wild1

Counterfeit installers to system compromise: Tracking a deceptive software download campaign

Microsoft tracks a counterfeit software-installer campaign compromising multinationals' China operations, moderately linked to the Silver Fox (Yinhu) actor.

Microsoft Defender Experts is tracking an active campaign using spoofed software download sites for brands such as Razer, Kaspersky, Microsoft Edge, Calibre, and Baidu Netdisk on .com.cn and .hl.cn domains, delivering installer archives whose hashes change per download, indicating server-side payload generation. The implants establish persistence, weaken security protections, and communicate with attacker-controlled infrastructure, with confirmed compromises across healthcare, manufacturing, gaming, technology, logistics, government, and education. Microsoft assesses with moderate confidence that the activity matches the publicly reported Silver Fox (Yinhu) fake software campaign; it has not attributed it to a nation-state actor.

Microsoft Security Blog · 14d agoThreat actor in the wild1

Fake Software Installers Disable Windows Update and Weaken Microsoft Defender

Fake software-download sites distribute installers that disable Windows Update and weaken Defender, attributed to China-linked cluster Silver Fox.

Microsoft says an active campaign uses counterfeit vendor websites on .com.cn and .hl.cn infrastructure with Chinese-language lures to deliver server-side generated installers that establish scheduled-task persistence, add Defender exclusions, delete shadow copies, and stop services including wuauserv, UsoSvc, uhssvc and WaaSMedicSvc. Victims span healthcare, manufacturing, gaming, technology, logistics, government and education, primarily China-based operations of multinationals and Chinese-speaking users. Microsoft assesses with moderate confidence the activity matches the Silver Fox (Yinhu) cluster, historically tied to Gh0st RAT and ValleyRAT, with C2 over non-standard ports like 5090 and 7088-7090 via domains iualef[.]net and oijfwe[.]net. Kaspersky separately detailed a QN Wallpaper DLL-sideloading chain delivering ValleyRAT.

The Hacker News · 13d agoMalware in the wild

Microsoft’s September 2026 Patch Tuesday addresses 964 CVEs (CVE-2026-81963, CVE-2026-85880)

Microsoft's September 2026 Patch Tuesday fixes a record 964 CVEs, including two zero-days actively exploited in the wild.

Microsoft patched a record 964 CVEs in its September 2026 Patch Tuesday release, with 101 rated critical and 824 rated important, making it the largest Patch Tuesday to date. The release includes fixes for two zero-days that were exploited in the wild, with CVE-2026-81963 and CVE-2026-85880 highlighted in the release. Affected products span Windows core components, Office, Exchange, .NET, Visual Studio, Active Directory services (including AD CS and AD FS) and numerous Azure services. Tenable notes the release surpasses July's as the biggest ever.

Tenable Blog · 7d agoVulnerability in the wildCVE-2026-81963CVE-2026-858801

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

Mustang Panda Adds Signed Windows Rootkit to CoolClient Backdoor for Stealth

Kaspersky reports Mustang Panda's updated CoolClient backdoor now deploys a signed kernel-mode Windows rootkit, hitting government victims in Myanmar, Mongolia, Pakistan, and Russia.

Kaspersky identified a new CoolClient variant attributed to HoneyMyte (Mustang Panda) that installs a digitally signed Windows kernel driver, msagent.sys, to hide and protect malicious processes, files, registry keys, and C2 network information. CoolClient is consistently deployed as a secondary backdoor after PlugX, with confirmed victims including government entities in Myanmar, Mongolia, Pakistan, and Russia. In a Myanmar campaign, PlugX was used to deploy CoolClient via a renamed Sangfor executable for DLL side-loading, a scheduled task for persistence, and RPC-based process creation with PPID spoofing. The driver, signed with a 2013 certificate issued to Nanjing Ranyi Technology, implements 33 IOCTL handlers, process hiding via unlinking, a filesystem minifilter, and registry callbacks.

The Hacker News · Aug 15, 2026Threat actor in the wild1

China-Linked Hackers Chain Chrome Zero-Day With Windows Kernel Flaw in Attacks

Volexity reports China-linked UTA0560 and JungleBamboo chained Chrome zero-day CVE-2026-85046 with kernel flaws to spy on NGOs.

Volexity documented campaigns detected on September 1, 2026, in which China-linked actors UTA0560 and JungleBamboo (APT31) chained CVE-2026-85046 (V8 type confusion), CVE-2026-87491 (WebAssembly sandbox escape), and CVE-2026-85880 (Windows kernel privilege escalation in RtlpCreateServerAcl). Victims were lured via links on legitimate U.S. university sites vulnerable to reflected XSS, then served hidden exploit iframes behind a donation-form image. Although a V8 fix had landed in Chromium's source after private August reporting, Chrome had not yet shipped it, creating a patch gap the actors exploited. The two groups installed distinct payloads: UTA0560 delivered the GRIMWEDGE JScript backdoor via DLL side-loading, while JungleBamboo used the SUPERSTOMP loader to install the LONGTALE credential-stealing Chrome extension disguised as Google Gemini.

GBHackersupdated · 1d agofirst · 4d agoExploit / PoC in the wild 20 sourcesCVE-2026-85046CVE-2026-87491CVE-2026-858802· 1 read

ValleyRAT: When Legitimate Software Becomes a Malware Delivery Tool

Kaspersky details ValleyRAT delivered via trojanized QN Wallpaper using DLL sideloading, tied to Silver Fox and hitting 1,500+ users in China and India.

Kaspersky found a malicious installer abusing a modified version of the legitimate QN Wallpaper adware application to deliver the ValleyRAT backdoor via DLL sideloading of libcef.dll. The installer masquerades as DingTalk, Chrome or Tencent Meeting software, creates persistence, disables Windows Defender via the DisableAntiSpyware registry key, and loads AES-encrypted payloads. ValleyRAT collects keystrokes, clipboard contents and screenshots plus system details, can download additional modules, and resists removal by injecting into svchost.exe or marking its process critical. The campaign was detected over 100,000 times in 2026, affecting more than 1,500 users mainly in China and India, and is attributed to Silver Fox with both espionage and financial motives.

Security Affairs · 15d agoMalware in the wild