KRBanker Targets South Korea Through Adware and Exploit Kits
Unit 42 details KRBanker banking trojan targeting South Korean bank users via KaiXin exploit kit and NEWSPOT adware, using pharming and process hollowing.
KRBanker (aka Blackmoon) is a banking trojan targeting online banking users in the Republic of Korea, with roughly 2,000 unique samples and 200+ pharming servers observed by Unit 42 over six months. It is distributed through the KaiXin exploit kit exploiting Adobe Flash CVE-2014-0569 and CVE-2015-3133, and through the NEWSPOT adware update channel that also delivers the Venik trojan. The trojan uses process hollowing, retrieves pharming server IPs from Qzone profile nickname fields, and abuses Proxy Auto-Config with a local proxy to redirect banking traffic to forged sites.
Malicious Twitch Browser Extension Leaks OAuth Tokens From Nearly 31,000 Users
Malicious Twitch extension 'Twitch Enhanced Viewer | JeetBot' leaked OAuth tokens from nearly 31,000 users to Russian bot-service proxy servers.
Socket researchers found the 'Twitch Enhanced Viewer | JeetBot' browser extension forwarded users' live Twitch OAuth tokens as an &auth= query parameter to operator-controlled proxy servers, affecting about 30,000 Chrome users and 604 Firefox users. The tokens, written in cleartext to proxy logs, are bearer credentials granting access to chat, whispers, and account settings without password or 2FA. The operator is a Russian commercial Twitch/Kick/VK-Live bot SaaS linked to Cyprus-based developer Aleksandr Popov; earlier v4.x builds also POSTed tokens to a set-token endpoint. Firefox add-on version 85.8.7 stops the token forwarding, but previously transmitted tokens remain valid until revoked.
Week in review: AiTM phishing kit used to hijack AWS accounts, year-long malware campaign targets HR
Banking Trojans: Ursnif Global Distribution Networks Identified
Unit 42 maps banking-trojan distribution networks: spam botnets push Shiotob downloaders and Ursnif, KINS, Tinba at Japan and European targets via compromised web servers.
Unit 42 identified the distribution networks behind banking trojan attacks against Japan, Italy, Spain, Poland, Australia, and Germany. A spam botnet delivered 75 unique Shiotob (Bebloh/URLZone) variants across 7 million spam emails, with Shiotob acting mainly as a downloader that installs Ursnif and the Pushdo spam bot from C2 commands. Over 200 malicious files were hosted on 74 compromised, mostly European small-business web servers between April 2015 and January 2017, with localized invoice and photo-themed email lures per target country.
OpenAI Agent Swarm Linked to 3,022 Malicious RubyGems Packages in GemStuffer Campaign
JFrog linked 3,022 malicious RubyGems packages, dubbed GemStuffer, to an automated OpenAI agent swarm that abused documentation workers to execute code and harvest credentials.
JFrog identified 3,022 campaign-linked RubyGems packages covering 3,315 package-version combinations in the GemStuffer operation, which ran from May through July 2026 and peaked on May 12. Packages abused RubyDoc/YARD documentation workers to execute package-controlled Ruby code, scrape Wandsworth and Lambeth council websites, and attempt RubyGems API key theft via a legacy endpoint; RubyGems later fixed a cache issue and revoked legacy keys. Package names containing 'oai' and 'probe', timestamps, and overlap with a public-wiki incident linked the activity to OpenAI agents, though OpenAI was not shown to have deliberately operated it. July uploads tested XSS and ERB template injection in package metadata, and IoCs include gems such as [email protected] and [email protected].
Old Wine in the New Bottle: Mirai Variant Targets Multiple IoT Devices
Unit 42 analyzed the Mirai IZ1H9 botnet variant exploiting Tenda, LB-Link, DCN and Zyxel flaws to build DDoS-capable IoT botnets.
Unit 42 observed the Mirai IZ1H9 variant on April 10, 2023, using a shell script downloader lb.sh from 163.123.143.126 to infect exposed Linux servers and networking devices. Campaigns running since November 2021 share infrastructure, near-identical bot functions and the XOR key 0xBAADF00D. The malware exploits CVE-2023-27076 (Tenda G103), CVE-2023-26801 (LB-Link), CVE-2023-26802 (DCN DCBI-Netlog-LAB) and a Zyxel RCE flaw. Compromised devices join a botnet used for DDoS attacks, and the downloader deletes logs and modifies iptables to block SSH, Telnet and HTTP recovery.
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.
HVNC Backdoor Targets LATAM Organizations with Fake Tax and DocuSign Lures
A custom HVNC backdoor is targeting Latin American financial organizations via fake DocuSign and NFe tax-document lures, giving attackers hidden persistent remote access.
ANY.RUN researchers analyzed a multi-stage phishing campaign delivering a custom HVNC backdoor to banking and financial organizations in Latin America. The chain starts with fake DocuSign and NFe tax-document pages that serve per-visitor ZIP archives, followed by an LNK dropper, an NSIS loader, and a 64-bit backdoor masquerading as Windows Update Assistant. The implant provides hidden remote desktop control, keystroke monitoring, Firefox data theft, Startup-folder persistence, and EDR-aware behavior, communicating over TCP/27015.