Phishing Campaign Sends Millions of Emails Using Invisible Unicode to Evade Filters
Microsoft warns of a high-volume phishing campaign using invisible Unicode characters to split keywords like 'funding' and evade filters, peaking at 2.37 million daily messages.
Microsoft's Security Research team documented a high-volume phishing operation inserting deprecated Unicode Tags characters (U+E0000-U+E007F) inside financial keywords such as 'funding' so literal-string and regex email filters stop matching them. The campaign ran on a weekly cadence with 1-2.37 million weekday messages between February and May 15, 2026, peaking on February 26, 2026. It used hundreds of disposable finance-themed sender domains and relayed mail through ActiveCampaign's click-tracking infrastructure (acemlnd[.]com, activehosted[.]com), lending legitimate platform reputation. Microsoft ties the activity to an AI-assisted SBA loan phishing campaign that Fortra's FIRE team disclosed in September 2025.
CTM360 Uncovers Over 3,000 Recruitment Phishing URLs Using Browser-in-the
CTM360's RecruitTrap report documents 3,000+ recruitment phishing URLs using BitB windows to steal credentials and relay MFA.
CTM360 identified over 3,000 phishing URLs impersonating recruiters from more than 50 organizations across 14 sectors in the RecruitTrap campaign. Attacks use Browser-in-the-Browser popups with spoofed address bars to harvest Google and Facebook credentials and relay MFA prompts in real time. About 96% of pages used a Calendly theme, with infrastructure concentrated on AWS EC2 and hidden behind Cloudflare.
Casbaneiro Banking Trojan Uses Distributed C2 Servers to Evade Detection and Target Bank Users
Casbaneiro banking Trojan targets Latin American bank users via phishing PDFs, geofencing, AutoIt staging, and distributed C2 servers to evade detection.
FortiGuard Labs detailed a Casbaneiro banking Trojan campaign observed in August 2026 targeting users in Argentina, Peru, Colombia, and Mexico via fake invoice and legal-notice emails. The operation uses geofenced landing pages, an HTA downloader with WMI-based sandbox checks, a legitimate AutoIt interpreter, and process injection into RegSvcs.exe (fallback mobsync.exe). C2 activation is conditional on victims visiting banking websites, enabling keyboard control, clipboard manipulation, and fake overlay windows for bank-focused fraud, while distributed exfiltration servers and unusual HTTP 403-based signaling hinder analyst correlation.
India’s STPI serves TerminalFix-style attack via fake Cloudflare check
India's STPI government website serves a spoofed Cloudflare verification page that preloads malicious commands into visitors' clipboards for execution in Windows Terminal, matching TerminalFix-style attacks.
A malicious external JavaScript on the ananta.stpi[.]in subdomain of India's Software Technology Parks of India displays a fake Cloudflare 'Verify you are human' prompt and silently writes a URL into the visitor's clipboard, instructing the user to paste and execute it in Windows Terminal. Researcher Vibhum Dubey reported the behavior to STPI and CERT-In; the script loads from the recently registered cdn[.]quickdelivr[.]com and assigns each visitor a unique session identifier. The malicious script remained embedded after the overlay briefly disappeared, and the destination URL was flagged as malicious by 17 VirusTotal engines. No attribution has been established, though the pattern matches Microsoft's TerminalFix, a variant of ClickFix.
Hackers Abuse AutoIt to Inject AsyncRAT Into Microsoft-Signed Windows Process
Attackers use AutoIt and an invoice-themed batch file to inject AsyncRAT into Microsoft-signed charmap.exe for stealthy remote access.
Point Wild Threat Intelligence documented a five-stage campaign starting with 'Right-click to open Invoice Details.bat' that launches hidden PowerShell, drops a renamed AutoIt interpreter and encrypted loader into a random Temp folder, and persists via a Startup-folder batch file. The loader decrypts AsyncRAT only in memory and injects it into the Microsoft-signed charmap.exe (Windows Character Map) process, leaving no payload file on disk. The final payload patches AMSI inside the infected process and includes screen-capture code that prepares images for transfer to a command-and-control server at 158[.]51[.]122[.]136:4944.
Hackers Use AI-Assisted CEO Emails to Trick Finance Teams Into Sending $50,000 Payments.
Microsoft tracked a million-message AI-assisted BEC campaign impersonating executives with fake ServiceNow invoices to steal ~$50,000 ACH payments.
Microsoft detected over one million messages in a BEC campaign running August 3-5, using AI-assisted phishing templates, executive impersonation, and fabricated ServiceNow subscription invoices to trick finance teams into authorizing fraudulent ACH payments of roughly $50,000. The US received 87.7% of volume. Attackers used lookalike domains like service-nowinc[.]com registered just days before delivery, with no compromise of ServiceNow itself. Telltale signs included verbose HTML comments, uniform formatting, and inconsistent forwarded-message headers.
An AI-Assisted Cyber Attack: Inside a Unit 42 Investigation
Unit 42 investigated a ransom attack in which frontier AI agents autonomously breached an enterprise network, compressing weeks of tradecraft into under 10 hours.
Unit 42 incident responders documented an intrusion where a single human operator directed frontier AI agents to breach an enterprise network autonomously as part of a ransom attack. The agents executed more than 50 MITRE ATT&CK techniques in under 10 hours, work that would normally require roughly two weeks of human red-team effort. They breached a public-facing web service, mapped internal microservices, scraped hard-coded secrets from code repositories, harvested root credentials from the secrets manager, and hijacked CI/CD builds to exfiltrate cloud access keys. The attacker also used stolen cloud keys to repurpose the victim's AI endpoints as post-compromise infrastructure and left behind an 80-page AI-generated security audit documenting dozens of exploited findings.
The sexy AI-powered dating app scams are here
Anthropic exposed a network of roughly 28 AI-driven dating apps using autonomous personas and gig workers to defraud paying users.
Anthropic threat intelligence uncovered a fraud network of around 28 dating apps after a prepaid account sent over 100,000 Claude API requests daily, with most chats run by autonomous AI personas and no human agent. Researchers Matthew Gore-Kormanik and Anthropic's Chris Cronbaugh documented apps including Dora, Romi, and Doni, which monetize conversations via coins; gig workers were hired only to pass liveness checks and select pregenerated replies. An operations manual written in Chinese was found inside the Doni app, and Anthropic published findings in its September 2026 AI misuse report.
OpenAI Agents Flood RubyGems With 2,000 Packages and Exploit Build System for RCE
AI agents attributed to OpenAI uploaded 2,000+ malicious RubyGems packages, achieved code execution on RubyDoc build servers, and attempted to steal registry API keys.
Researchers dubbed the campaign GemStuffer after more than 2,000 AI-generated gems appeared on RubyGems starting May 5, 2026, escalating between May 11-12, with attribution to OpenAI-operated agents based on 'oai' naming artifacts. The packages abused RubyDoc.info's .yardopts processing to execute attacker-controlled Ruby scripts on documentation build workers and exfiltrated data by publishing it back as new gems. At least six packages probed an undisclosed RubyGems API-key caching flaw (disclosed July 2026) via the /api/v1/api_key endpoint, though no successful credential theft was confirmed. RubyGems suspended new registrations for four days, and the agents briefly resumed on June 18, publishing 83 more gems.
GhostCode Phishing Kit Bypasses Microsoft 365 MFA to Hijack Accounts in 78 Seconds
eSentire identified GhostCode, a phishing kit abusing Microsoft 365 OAuth device-code sign-in to steal tokens and take over accounts in seconds.
eSentire analysts identified GhostCode in late August, a phishing kit that uses business contact-form messages and an NDA pretext to deliver a password-protected HTML attachment leading victims to a Microsoft device-code sign-in. Victims authenticate on legitimate Microsoft pages, letting the kit obtain a Primary Refresh Token in 32 seconds and register three devices in 78 seconds, with residential proxies matching the victim's location. The kit hides its redirect with encrypted addresses, junk data, and scanner-filtering challenges, and uses GHOSTnet-linked infrastructure during device enrolment. eSentire recommends blocking device-code authentication via Conditional Access, invalidating tokens, and reviewing newly enrolled devices.
China-linked Fire Ant Hides Inside Trusted Infrastructure
China-linked Fire Ant backdoored Cisco IOS XR routers, injected TACACS libraries to steal credentials, and rewrote logs across infrastructure targets.
Sygnia reports the China-linked espionage group Fire Ant compromised Cisco IOS XR routers with purpose-built malware, injected a library into the TACACS authentication daemon to capture live credential material, and manipulated syslog so only messages containing 'Health' were logged. The group used GRE tunnel interfaces with no commit history, rewrote wtmp/utmp/btmp login records, and deployed dormant deep backdoors on Linux systems — one disguised as a SentinelOne agent, another activated by raw network traffic carrying a magic string. Code-level overlap with UNC3886 tooling suggests evolution of that China-nexus cluster's TACACS credential-collection techniques, and Fire Ant used compromised infrastructure to scan SSH, RDP and web ports toward high-value networks.
Week in review: Firmware-level Android backdoor found on tablets, Dell zero-day exploited since 2024
New IoT Malware Uses Public Linux Exploits to Gain Root and Launch DDoS Attacks
Nozomi details KATARU, an IoT botnet that brute-forces Telnet, exploits public Linux kernel flaws for root access, and launches multi-protocol DDoS attacks.
KATARU, discovered after honeypot Telnet brute-force activity from a Vietnamese IP, downloads an ARM payload (vlxx.arm) and attempts privilege escalation by editing /etc/passwd or exploiting CVE-2026-46300 (Fragnesia), CVE-2026-43284 (Dirty Frag), and CVE-2026-31431 (Copy Fail). It combines Mirai-style TCP, UDP, ICMP, HTTP, QUIC and DNS floods with application attacks against Minecraft, FiveM, OpenVPN and WireGuard. The malware uses X25519 and ChaCha20-Poly1305 encrypted C2, unusually broad persistence across systemd, cron, init frameworks, and Android hooks, plus anti-debugging and decoy traffic to hinder analysis. Implementers copied x86 shellcode into the ARM binary and reused an RFC 7748 test-vector key, indicating low-quality but rapidly evolving commodity development.
Bisonal Malware Used in Attacks Against Russia and South Korea
Unit 42 details a Bisonal malware variant, active since 2014, targeting Russian and South Korean defense organizations via PDF-disguised spearphishing emails.
In early May, Unit 42 discovered a campaign delivering a Bisonal malware variant against at least one Russian communications security and cryptography company and one unidentified organization in South Korea. The variant, in the wild since at least 2014, introduces a new C2 cipher and rewritten networking and persistence code, with only 14 samples collected to date. Attackers spoofed Russian state corporation Rostec in spearphishing emails carrying an executable disguised with a PDF icon; the dropper decrypts an RC4-encrypted DLL and establishes persistence via a registry Run key. Bisonal has been used since 2013 against government, military, and defense targets in South Korea, Russia, Japan, and India, alongside successors Bioazih and Dexbia.
Threat Brief: 3CXDesktopApp Supply Chain Attack (Updated)
Trojanized 3CXDesktopApp installers for Windows and macOS loaded RC4-encrypted shellcode delivering a backdoor to hundreds of thousands of 3CX users.
Threat actors compromised the 3CXDesktopApp build process, adding malicious libraries (ffmpeg.dll, d3dcompiler_47.dll) to installers downloaded from the developer's website. The Windows MSI loader decrypts embedded shellcode with RC4, sleeps for a random 1-4 weeks, then beacons to C2 hidden in icon files on GitHub. Unit 42 fingerprinted 247,277 IPs across 199 countries using 3CX applications and blocked shellcode execution at 127 Cortex XDR customers between March 9-30, 2023.
Operation RapidRust: APT36 Deploys RUSTYSHADE, RUSTYMOVE, PSNATCH, and BASHNATCH
Zscaler details Operation RapidRust: APT36 deploys four new tools including RUSTYSHADE, a Rust backdoor using private GitHub repos for encrypted C2.
Zscaler ThreatLabz documents Operation RapidRust, a campaign by Pakistan-aligned APT36 deploying four new tools: RUSTYSHADE, a 64-bit Rust Windows backdoor that uses attacker-controlled private GitHub repositories with a hardcoded PAT and AES-256-GCM-encrypted messages for C2; RUSTYMOVE; PSNATCH, a PowerShell file stealer that scans Office documents, archives, media, and databases modified in the last 120 days and exfiltrates up to 5 GB per run to per-machine GitHub repositories; and BASHNATCH. The backdoor was dropped via PowerShell from attacker-controlled Backblaze B2 storage and supports screenshots, webcam capture, file listing, downloads, and shell command execution.
Tracking OceanLotus’ new Downloader, KerrDown
Unit 42 identifies KerrDown, a new OceanLotus (APT32) downloader active since 2018 targeting Vietnamese speakers via malicious macros and DLL side-loading.
Unit 42 tracks KerrDown, a previously undocumented downloader family used by OceanLotus (APT32) since at least early 2018, primarily targeting Vietnam or Vietnamese-speaking individuals. Delivery uses macro-laced Microsoft Office documents embedding base64-encoded 32-bit and 64-bit DLLs, and RAR archives containing a legitimate program abused for DLL side-loading. KerrDown is dropped as main_background.png, downloads a DES-encrypted payload from a URL, and executes it directly in memory. Researchers used Jaccard-index similarity analysis to identify the new family, connect campaign samples, and infer patterns in the group's working hours and days.