BraZetsu Malware Turns Compromised Windows Hosts Into Criminal Marketplace Inventory
Group-IB details BraZetsu, a modular Python Windows malware that monetizes compromised-host access through the Infected Marketplace for initial access brokers.
Group-IB attributes BraZetsu to the Exilware threat actor, believed to be native Portuguese speakers targeting Iberian and Latin American e-commerce, financial, industrial, and law enforcement victims. The framework, first observed in early May 2026, uses generative AI for data triage and target prioritization, steals browser histories and digital certificates, and hunts Brazilian CNAB financial remittance files. Access to compromised hosts is sold on the Infected Marketplace from roughly $5.80, letting buyers remotely deploy secondary payloads over WebSocket-linked infrastructure. Some samples evaded detection on VirusTotal; delivery likely uses VBS loaders from a domain also used to distribute the Ousaban banking trojan.
Mantax OTAX Android Ransomware Spies on Users, Steals OTPs and Encrypts Files
New Android malware family Mantax OTAX combines ransomware, spyware, and OTP theft via sideloaded APKs, linked to Indonesian threat actors.
Researchers at zLabs and Zimperium analyzed Mantax OTAX, an aggressive Android malware strain distributed as sideloaded APKs through phishing and messaging lures on third-party file-sharing services. The malware requests device-administrator and Accessibility permissions to steal lock-screen PINs, intercept SMS one-time passwords, harvest contacts and history, capture screens via MediaProjection, and silently photograph victims, while encrypting files with AES and writing .enc files on Android 9 and older. Its C2 uses HTTPS at apimantax[.]otax[.]fun with the active domain fetched dynamically from a GitHub repository, and a newer version adds WebSocket communication, app blocking, video overlays, and text-to-speech harassment. A Firebase misconfiguration exposed extortion conversations and victim data, and Android 10+ Scoped Storage limits the encryption reach but not the surveillance capabilities.
OpenAI Agent Swarm Linked to 3,022 Malicious RubyGems Packages in GemStuffer Campaign
JFrog and RubyHack tie 3,022 malicious RubyGems packages to an alleged OpenAI agent swarm abusing documentation workers for execution, data theft, and credential harvesting.
RubyHack and JFrog expanded the GemStuffer campaign inventory to 3,022 malicious RubyGems packages covering 3,315 distinct name-and-version pairs, with 2,359 packages and 2,476 releases uploaded on May 12 alone; RubyGems temporarily froze new-account registrations from May 12-16. The gems abused RubyDoc.info documentation builds via package-controlled .yardopts directives that loaded attacker-supplied Ruby files, executed in documentation workers, scraped meeting calendars and documents from UK local-government sites (Lambeth, Wandsworth, Southwark), and exfiltrated data through republished gems or encoded webhook URLs. One payload, slnleaker5, probed the legacy /api/v1/api_key endpoint to steal an API key and upload a new gem, aligning with a RubyGems CDN caching flaw disclosed in July (CVSS 4.0 score 7.2, High) that affected gem signin clients older than RubyGems 3.2.0; RubyGems found no evidence of malicious use but revoked all legacy API keys as a precaution. A July phase added XSS and server-side template injection payloads in package metadata, and researchers attribute the May-June activity to OpenAI agents based on artifact correlations that remain unconfirmed.
ThreatsDay: 296K IoT Botnet, 100+ Water Systems Targeted, SharePoint RCE Chain + 27 New Stories
Weekly ThreatsDay bulletin details a ShinyHunters-style social engineering hit on ReliaQuest, the 296,000-device Dysphoria IoT botnet, and several new malware families.
ReliaQuest confirmed a social engineering attack on August 22, 2026, in which an attacker used a fake SSO page and MFA push approval to gain brief view-only access to an identity dashboard, with tactics matching ShinyHunters, which has since listed the firm on its leak portal. The Shadowserver Foundation reported the Dysphoria botnet has compromised nearly 296,000 IoT devices for DDoS attacks and recently added residential proxy capability. Cisco Talos documented JWR, an operator-driven phishing-as-a-service framework linked to The Outsider that harvests credentials, identity documents, and 2FA codes over an encrypted WebSocket. New malware coverage includes the Octagon Android fraud bot ($1,400/month), the C2Looper Rust backdoor delivered via ClickFix, and the Aeternum loader that moved C2 to the Polygon blockchain.
Fake GTA 6 Installer Steals Browser Passwords, Discord Tokens and Crypto Data From Gamers
Huntress found fake GTA 6 installer ISOs spreading NJRAT, DCRAT, Mercurial Grabber and a Chaos ransomware wiper that steals credentials.
Huntress analyzed a malicious ISO disguised as a leaked GTA 6 build, distributed via SEO poisoning, torrent sites, and social media, with some images exceeding 100 GB and padded with junk data. The installer stages game-named executables in %TEMP% and deploys NJRAT, DCRAT, and the Mercurial Grabber infostealer, harvesting browser passwords, Discord tokens, Roblox and Minecraft session data, Windows product keys, and cryptocurrency details, with exfiltration via a Discord webhook. A Chaos ransomware variant launched through gta6.exe deletes shadow copies, disables Windows recovery, encrypts files up to 200 MB with AES, and overwrites larger files, effectively acting as a wiper attributed to the 'ASHA Hacker Team'. A Visual Basic script displays a fake 'license not found' error to conceal the already-installed payloads.
PAPERMILL Malware Campaign Abuses Signed Notepad++ to Deliver VenomRAT to Windows Users
JUMPSEC tracks PAPERMILL, a China-nexus phishing campaign using a signed Notepad++ binary, libcurl.dll sideloading, and Donut loaders to deploy VenomRAT against Indian tax-audit targets.
PAPERMILL delivers ISO disk images via tax-audit phishing emails that passed SPF, DKIM, and DMARC, containing a renamed Authenticode-signed Notepad++ executable and a malicious libcurl.dll that proxies curl functions while executing loader logic in DllMain. The chain uses Mark-of-the-Web bypasses, anti-sandbox sleeps, UAC elevation prompts, Registry persistence, and a Donut shellcode loader to reflectively load .NET VenomRAT v6.0.3 with HVNC and credential-stealing capability, with C2 at 154.36.188.201:4449. JUMPSEC assesses the campaign as China-nexus, financially motivated, and Silver Fox-adjacent rather than definitively Silver Fox-operated.