North Korea-linked Hackers Hide a Backdoor Inside HAProxy
Rapid7 reports North Korea-linked hackers implanted a backdoor compiled into HAProxy at South Korean automotive and media firms, enabling covert C2 and credential theft.
Rapid7 documented a previously undocumented Linux toolkit hitting South Korean automotive and media organizations, centered on a backdoor compiled directly into victims' HAProxy 2.8.12. The 'ted backdoor' uses HAProxy's native filter API to intercept HTTP traffic, receive C2 commands hidden in requests to a fake image path, and erase all traces from logs and counters; the toolkit also trojanizes crond, agetty, atd, sshd, and polkitd, adds an SSH keylogger, and runs curlRAT with virtualization checks. It can inject scripts or replace page content for selected victims, turning the load balancer into a watering hole. Attribution sits at medium confidence toward North Korean state actors, with overlaps to APT37-linked infrastructure and a concurrent Lazarus campaign; the campaign's command domains have since gone dark.
FrostyGoop’s Zoom-In: A Closer Look into the Malware Artifacts, Behaviors and Network Communications
Unit 42 dissects FrostyGoop OT malware, which sent Modbus TCP commands to disrupt heating for 600+ apartment buildings in Ukraine.
Palo Alto Unit 42 analyzed new FrostyGoop/BUSTLEBERM samples, the ninth known ICS-centric malware, first used against a Ukrainian municipal energy company by sending Modbus TCP commands to ENCO control devices. The attack caused a two-day heating outage affecting over 600 apartment buildings during sub-zero temperatures. The Go-compiled malware accepts Modbus register operations and timing parameters via command-line arguments or a JSON configuration file, uses an obscure open-source Modbus library, and checks the Windows BeingDebugged flag to evade debuggers. Unit 42 telemetry recorded over 1 million Modbus TCP devices exposed to the internet between September and October 2024.
xHunt Campaign: Attacks on Kuwait Shipping and Transportation Organizations
xHunt deployed custom backdoors Hisoka, Killua, Gon, and EYE against Kuwait shipping and transportation organizations, using DNS tunneling and email-draft C2 channels.
Unit 42 observed the xHunt campaign targeting Kuwait transportation and shipping organizations between May and June 2019, installing backdoors named after characters from the anime Hunter x Hunter, including Hisoka, Killua, Sakabota, and Netero. The tools use HTTP and DNS tunneling for C2, and Hisoka v0.9 added an unusual email-based C2 channel that abuses Exchange Web Services with stolen credentials to exchange email drafts. The Gon tool provides port scanning, file transfer, screenshots, remote command execution, and RDP session creation, while EYE acts as a cleanup failsafe if a legitimate user logs in. Related activity targeting Kuwait between July and December 2018 was reported by IBM X-Force IRIS, suggesting the campaigns are likely related.
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.
UBoatRAT Navigates East Asia
Unit 42 discovers UBoatRAT, a new custom RAT targeting South Korean and video-game industry personnel, delivered via Google Drive with GitHub-based C2 and BITS persistence.
Unit 42 identified UBoatRAT, a new custom remote access trojan first found in May 2017, whose initial version used a public Hong Kong blog service and a compromised Japanese web server for command and control. The latest variants target personnel or organizations related to South Korea or the video games industry, are delivered through Google Drive, and masquerade as Microsoft Word, Excel, or folder icons. The RAT checks for virtualization software and domain join, retrieves its C2 address from a Base64-encoded string in a GitHub-hosted file, uses a custom XOR-encrypted C2 protocol, and maintains persistence via Windows Background Intelligent Transfer Service (BITS) jobs that survive reboots.
DeadLock Ransomware Uses Polygon Smart Contracts to Make Extortion Infra Harder to Disrupt
Microsoft reports DeadLock ransomware using Polygon smart contracts and Session messaging for extortion infrastructure, claiming 96 victims across Europe and the U.S.
Microsoft Threat Intelligence reports the DeadLock ransomware operation uses the Session messaging network and Polygon blockchain smart contracts to host victim chat, proxy server addresses, and its data leak blog, making takedowns harder. First detected in July 2025, the group has claimed 96 victims, mostly in Italy, Spain, Poland, Türkiye, and the U.S., with deployments by affiliates of Lynx and INC ransomware. The encryptor uses Curve25519 with XChaCha20, drops an interactive HTML recovery chat application, geofences CIS-linked countries, and clears logs and shadow copies to evade forensics.