China-Linked UAT-7290 Targets Telecoms with Linux Malware and ORB Nodes

The China-linked threat actor PlushDaemon has been hijacking software update traffic using a new implant called EdgeStepper in cyberespionage operations since 2018. The group targets individuals and organizations in the U.S., China, Taiwan, Hong Kong, South Korea, New Zealand, and Cambodia, deploying custom malware like the SlowStepper backdoor. The attackers compromise routers via known vulnerabilities or weak passwords, install EdgeStepper to redirect update traffic, and deliver the LittleDaemon malware downloader. This leads to the deployment of the SlowStepper backdoor, which enables extensive system control and data theft. EdgeStepper is a Go-based network backdoor that redirects all DNS queries to a malicious hijacking node, facilitating adversary-in-the-middle (AitM) attacks. In May 2024, PlushDaemon targeted a South Korean VPN provider named IPany. The group uses an ELF file named bioset, internally called dns_cheat_v2, to forward DNS traffic to a malicious DNS node. They deploy two downloaders, LittleDaemon and DaemonLogistics, which deliver a backdoor toolkit for cyber espionage operations.

Government and telecommunications organizations in Africa, the Middle East, and Asia have been targeted by a China-aligned nation-state actor known as Phantom Taurus over the past two-and-a-half years. The group focuses on espionage, targeting ministries of foreign affairs, embassies, geopolitical events, and military operations. Phantom Taurus employs custom-developed tools and techniques, including a bespoke malware suite named NET-STAR, to maintain long-term intelligence collection and obtain confidential data from targets of strategic interest to China. The group's activities coincide with major global events and regional security affairs, demonstrating stealth, persistence, and adaptability in their tactics, techniques, and procedures (TTPs). Phantom Taurus has been observed using a .NET malware suite named NET-STAR to breach IIS web servers, which operates almost entirely in memory and includes a fileless backdoor that establishes encrypted command-and-control (C2) sessions. The suite includes a backdoor named IIServerCore that accepts commands and encoded .NET payloads, enabling arbitrary code execution on compromised systems. The suite also includes two AssemblyExecuter loaders (v1 and v2) that allow dynamic loading of additional .NET malware, with v2 featuring advanced evasion techniques such as AMSI and ETW bypass. The group uses custom SQL queries to search for specific tables and keywords on compromised systems, exporting all matching results. Additionally, Phantom Taurus's operational methods are supported by other custom malware, including TunnelSpecter and SweetSpecter, which are used for email exfiltration.

The BRICKSTORM malware, attributed to PRC state-sponsored actors, has been used for long-term espionage against U.S. organizations, particularly in the technology, legal, SaaS, and BPO sectors. The malware, a Go-based backdoor, has been active for over a year, with an average dwell time of 393 days. It targets appliances without EDR support, such as VMware vCenter/ESXi, and uses legitimate traffic to mask its C2 communications. The attackers aim to exfiltrate emails and maintain stealth through various tactics, including removing the malware post-operation to hinder forensic investigations. The malware serves multiple functions, including web server, file manipulation, dropper, SOCKS relay, and shell command execution. The attackers use a malicious Java Servlet Filter (BRICKSTEAL) on vCenter to capture credentials and clone Windows Server VMs to extract secrets. The stolen credentials are used for lateral movement and persistence, including enabling SSH on ESXi and modifying startup scripts. The malware exfiltrates emails via Microsoft Entra ID Enterprise Apps, utilizing its SOCKS proxy to tunnel into internal systems and code repositories. UNC5221 focuses on developers, administrators, and individuals tied to China's economic and security interests. Mandiant has released a free scanner script to help defenders detect BRICKSTORM. CISA, NSA, and Cyber Centre issued a joint report on BRICKSTORM, providing IOCs, detection signatures, and recommended mitigations. The report highlights BRICKSTORM's advanced functionality to conceal communications, move laterally, and tunnel into victim networks. The malware automatically reinstalls or restarts if disrupted, and PRC actors are primarily targeting government and IT sector organizations. CISA analyzed eight BRICKSTORM samples from victim organizations and urges organizations to contact CISA if they detect BRICKSTORM or related activity. CISA warns that Chinese hackers have been backdooring VMware vSphere servers with Brickstorm malware, using multiple layers of encryption and a self-monitoring function to maintain persistence. The attackers compromised a web server in an organization's DMZ in April 2024, moved laterally to an internal VMware vCenter server, and deployed malware. They also hacked two domain controllers and exported cryptographic keys after compromising an ADFS server, maintaining access from at least April 2024 through September 2025. The attackers captured Active Directory database information and performed system backups to steal legitimate credentials and other sensitive data. CrowdStrike linked these attacks to a Chinese hacking group it tracks as Warp Panda, which also deployed previously unknown Junction and GuestConduit malware implants in VMware ESXi environments. The U.S. Cybersecurity and Infrastructure Security Agency (CISA) on Thursday released details of a backdoor named BRICKSTORM that has been put to use by state-sponsored threat actors from the People's Republic of China (PRC) to maintain long-term persistence on compromised systems. BRICKSTORM is a sophisticated backdoor for VMware vSphere and Windows environments, enabling cyber threat actors to maintain stealthy access and providing capabilities for initiation, persistence, and secure command-and-control. Written in Golang, the custom implant gives bad actors interactive shell access on the system and allows them to browse, upload, download, create, delete, and manipulate files. The malware, mainly used in attacks targeting governments and information technology (IT) sectors, also supports multiple protocols, such as HTTPS, WebSockets, and nested Transport Layer Security (TLS), for command-and-control (C2), DNS-over-HTTPS (DoH) to conceal communications and blend in with normal traffic, and can act as a SOCKS proxy to facilitate lateral movement. The cybersecurity agency did not disclose how many government agencies have been impacted or what type of data was stolen. The activity represents an ongoing tactical evolution of Chinese hacking groups, which have continued to strike edge network devices to breach networks and cloud infrastructures. In a statement shared with Reuters, a spokesperson for the Chinese embassy in Washington rejected the accusations, stating the Chinese government does not "encourage, support or connive at cyber attacks.". BRICKSTORM was first documented by Google Mandiant in 2024 in attacks linked to the zero-day exploitation of Ivanti Connect Secure zero-day vulnerabilities (CVE-2023-46805 and CVE-2024-21887). The use of the malware has been attributed to two clusters tracked as UNC5221 and a new China-nexus adversary tracked by CrowdStrike as Warp Panda. Earlier this September, Mandiant and Google Threat Intelligence Group (GTIG) said they observed legal services, software-as-a-service (SaaS) providers, Business Process Outsourcers (BPOs), and technology sectors in the U.S. being targeted by UNC5221 and other closely related threat activity clusters to deliver the malware. A key feature of the malware, per CISA, is its ability to automatically reinstall or restart itself by means of a self-monitoring function that allows its continued operation in the face of any potential disruption. In one case detected in April 2024, the threat actors are said to have accessed a web server inside an organization's demilitarized zone (DMZ) using a web shell, before moving laterally to an internal VMware vCenter server and implanting BRICKSTORM. However, many details remain unknown, including the initial access vector used in the attack and when the web shell was deployed. The attackers have also been found to leverage the access to obtain service account credentials and laterally move to a domain controller in the DMZ using Remote Desktop Protocol (RDP) so as to capture Active Directory information. Over the course of the intrusion, the threat actors managed to get the credentials for a managed service provider (MSP) account, which was then used to jump from the internal domain controller to the VMware vCenter server. CISA said the actors also moved laterally from the web server using Server Message Block (SMB) to two jump servers and an Active Directory Federation Services (ADFS) server, exfiltrating cryptographic keys from the latter. The access to vCenter ultimately enabled the adversary to deploy BRICKSTORM after elevating their privileges. CrowdStrike, in its analysis of Warp Panda, said it has detected multiple intrusions targeting VMware vCenter environments at U.S.-based legal, technology, and manufacturing entities this year that have led to the deployment of BRICKSTORM. The group is believed to have been active since at least 2022. Warp Panda exhibits a high level of technical sophistication, advanced operations security (OPSEC) skills, and extensive knowledge of cloud and virtual machine (VM) environments. Warp Panda demonstrates a high level of stealth and almost certainly focuses on maintaining persistent, long-term, covert access to compromised networks. Evidence shows the hacking group gained initial access to one entity in late 2023. Also deployed in the attacks alongside BRICKSTORM are two previously undocumented Golang implants, namely Junction and GuestConduit, on ESXi hosts and guest VMs, respectively. Junction acts as an HTTP server to listen for incoming requests and supports a wide range of capabilities to execute commands, proxy network traffic, and interact with guest VMs through VM sockets (VSOCK). GuestConduit, on the other hand, is a network traffic-tunneling implant that resides within a guest VM and establishes a VSOCK listener on port 5555. Its primary responsibility is to facilitate communication between guest VMs and hypervisors. Initial access methods involve the exploitation of internet-facing edge devices to pivot to vCenter environments, either using valid credentials or abusing vCenter vulnerabilities. Lateral movement is achieved by using SSH and the privileged vCenter management account "vpxuser." The hacking crew has also used the Secure File Transfer Protocol (SFTP) to move data between hosts. Some of the exploited vulnerabilities are listed below - CVE-2024-21887 (Ivanti Connect Secure), CVE-2023-46805 (Ivanti Connect Secure), CVE-2024-38812 (VMware vCenter), CVE-2023-34048 (VMware vCenter), CVE-2021-22005 (VMware vCenter), CVE-2023-46747 (F5 BIG-IP). The entire modus operandi revolves around maintaining stealth by clearing logs, timestomping files, and creating rogue VMs that are shut down after use. BRICKSTORM, masquerading as benign vCenter processes, is employed to tunnel traffic through vCenter servers, ESXi hosts, and guest VMs. Similar to details shared by CISA, CrowdStrike noted that the attackers used their access to vCenter servers to clone domain controller VMs, possibly in a bid to harvest the Active Directory Domain Services database. The threat actors have also been spotted accessing the email accounts of employees who work in areas that align with Chinese government interests. Warp Panda likely used their access to one of the compromised networks to engage in rudimentary reconnaissance against an Asia Pacific government entity. They also connected to various cybersecurity blogs and a Mandarin-language GitHub repository. Another significant aspect of Warp Panda's activities is their focus on establishing persistence in cloud environments and accessing sensitive data. Characterizing it as a "cloud-conscious adversary," CrowdStrike said the attackers exploited their access to entities' Microsoft Azure environments to access data stored in OneDrive, SharePoint, and Exchange. In at least one incident, the hackers managed to get hold of user session tokens, likely by exfiltrating user browser files and tunneled traffic through BRICKSTORM implants to access Microsoft 365 services via a session replay attack and download SharePoint files related to the organization's network engineering and incident response teams. The attackers have also engaged in additional ways to set up persistence, such as by registering a new multi-factor authentication (MFA) device through an Authenticator app code after initially logging into a user account. In another intrusion, the Microsoft Graph API was used to enumerate service principals, applications, users, directory roles, and emails. The adversary primarily targets entities in North America and consistently maintains persistent, covert access to compromised networks, likely to support intelligence-collection efforts aligned with PRC strategic interests.

Chinese state-sponsored APT actors have **dramatically escalated cyber operations against Taiwan**, with the National Security Bureau (NSB) reporting **960,620,609 intrusion attempts** in 2025—a **6% year-over-year increase** and **112.5% surge since 2023**. The **energy sector** faced a **tenfold spike in attacks**, while **emergency/hospital systems** saw a **54% rise**, including **ransomware deployments** that disrupted operations in at least **20 hospitals** and led to stolen medical data being sold on dark web forums. The campaigns, attributed to **BlackTech, Flax Typhoon, Mustang Panda, APT41, and UNC3886**, leveraged **hardware/software vulnerabilities, DDoS, social engineering, and supply-chain compromises**, often combining tactics. Attacks correlated with **PLA military drills, political events, and visits by Taiwanese officials**, peaking in **May 2025** during President Lai Ching-te’s inauguration anniversary. Taiwan’s NSB is now collaborating with **30+ countries** on joint investigations, marking a significant expansion in international coordination against PRC cyber threats. Earlier phases of this campaign targeted **U.S. government agencies (CBO, Treasury, CFIUS)**, **European telecoms**, and global critical infrastructure via exploits in **Cisco, Ivanti, Palo Alto, and Citrix devices**. Advisories from **CISA, NSA, and allies** warn of a shift from espionage to **potential disruptive capabilities**, while **Operation "WrtHug"** hijacked **50,000+ ASUS routers** (predominantly in Taiwan) for persistent access. Despite vendor patches, **unpatched or end-of-life devices remain at risk** of compromise by Chinese APTs and follow-on threat actors.

UNC6384, a China-nexus threat actor, has been targeting diplomats in Southeast Asia and other entities globally to advance Beijing's strategic interests. The group employs a multi-stage attack chain leveraging advanced social engineering, valid code signing certificates, adversary-in-the-middle (AitM) attacks, and indirect execution techniques to evade detection. The campaign, detected in March 2025, uses captive portal redirections to deliver a PlugX variant called SOGU.SEC. The attacks involve redirecting web traffic through a captive portal to a threat actor-controlled website, downloading a digitally signed downloader (STATICPLUGIN), and deploying the SOGU.SEC backdoor in memory. The malware supports commands to exfiltrate files, log keystrokes, and launch remote command shells. The campaign highlights the sophistication of PRC-nexus threat actors and their evolving operational capabilities. The campaign targeted around two dozen victims, primarily Southeast Asian diplomats, between March and July 2025. The attack chain involved compromised edge devices intercepting captive portal checks and redirecting users to a malicious website. The malicious website used a valid TLS/SSL certificate issued by Let's Encrypt to avoid browser security warnings. The first-stage malware, STATICPLUGIN, dropped a launcher called CANONSTAGER, which used unconventional techniques to hide its activities. The final payload was a variant of the PlugX backdoor, tracked by Google as SOGU.SEC. In September 2025, new information revealed that the PlugX variant overlaps with RainyDay and Turian backdoors, targeting telecommunications and manufacturing sectors in Central and South Asia. The campaign is linked to Mustang Panda, which also uses Bookworm malware. Bookworm has been used since 2015 and includes capabilities to execute commands, upload/download files, exfiltrate data, and establish persistent access.