A cyberespionage group known in security research circles as PlushDaemon has been carrying out a long-running operation in which they take advantage of software update systems to secretly install their own tools on targeted computers. According to new analysis by ESET, this group has been active for several years and has repeatedly improved its techniques. Their operations have reached both individuals and organizations across multiple regions, including areas in East Asia, the United States, and Oceania. Victims have included universities, companies that manufacture electronics, and even a major automotive facility located in Cambodia. ESET’s data suggests that this shift toward manipulating software updates has been a consistent part of PlushDaemon’s strategy since at least 2019, which indicates the group has found this method to be reliable and efficient.
The attackers begin by attempting to take control of the network equipment that people rely on for internet connectivity, such as routers or similar devices. They usually exploit security weaknesses that are already publicly known or take advantage of administrators who have left weak passwords unchanged. Once the attackers get access to these devices, they install a custom-built implant researchers call EdgeStepper. This implant is written in the Go programming language and compiled in a format that works comfortably on Linux-based router systems. After deployment, EdgeStepper operates quietly in the background, monitoring how the device handles internet traffic.
What makes this implant dangerous is its ability to interfere with DNS queries. DNS is the system that helps computers find the correct server whenever a user tries to reach a domain name. EdgeStepper watches these requests and checks whether a particular domain is involved in delivering software updates. If EdgeStepper recognizes an update-related domain, it interferes and redirects the request to a server controlled by PlushDaemon. The victim sees no warning sign because the update process appears completely normal. However, instead of downloading a legitimate update from the software provider, the victim unknowingly receives a malicious file from the attackers’ infrastructure.
This deceptive update carries the first stage of a layered malware chain. The initial file is a Windows component known as LittleDaemon. It is intentionally disguised as a DLL file to convince the system that it is a harmless library file. Once LittleDaemon runs, it connects to one of the attacker-controlled nodes and downloads the next stage, known as DaemonicLogistics. This second-stage tool is decrypted and executed directly in memory, which makes it more difficult for traditional security products to spot because it avoids writing visible files to disk. DaemonicLogistics is essentially the bridge that loads the final and most important payload.
The last payload is the group’s advanced backdoor, SlowStepper. This backdoor has been documented in earlier incidents, including a case in which users of a South Korean VPN service unknowingly received a trojanized installer from what appeared to be the vendor’s official site. SlowStepper gives the attackers broad access to a compromised machine. It can gather system information, execute various commands, browse and manipulate files, and activate additional spyware tools. Many of these tools are written in Python and are designed to steal browser data, capture keystrokes, and extract stored credentials, giving PlushDaemon a detailed picture of the victim’s activity.
ESET researchers also examined the group’s interference with update traffic for Sogou Pinyin, which is one of the most widely used Chinese input software products. While this example helps illustrate the group’s behavior, the researchers observed similar hijacking patterns affecting other software products as well. This means PlushDaemon is not focused on one specific application but is instead targeting any update system they can manipulate through the network devices they have compromised. Because their technique relies on controlling the network path rather than exploiting a flaw inside the software itself, the group’s approach could be applied to targets anywhere in the world.
The research report includes extensive technical information on every component uncovered in this campaign and offers indicators of compromise for defenders, including associated files, domains, and IP addresses. These findings suggest how imperative it is that a routine process like installing updates can become a highly effective attack vector when network infrastructure is tampered with. The case also reinforces the importance of securing routers and keeping administrator credentials strong, since a compromised device at the network level allows attackers to alter traffic without the user noticing any warning signs.
The White House recently brought together U.S. telecommunications executives to discuss a cyberespionage campaign attributed to Chinese-backed hackers. The attacks have been described by experts as the "worst telecom hack in U.S. history," compromising major telecom providers and targeting national security intelligence.
According to reports, the FBI said several breaches had occurred at telecommunications companies where attackers made off with sensitive data including call records and communications that the hackers could access due to government-mandated backdoors. The intrusion, according to reports, was done by a group code-named Salt Typhoon that has connections to China's Ministry of State Security. It is said to have engaged in espionage activities against officials from U.S. presidential campaigns.
The key telecom providers like AT&T, Verizon, and Lumen have been listed as victims of this cyberattack. Recently, T-Mobile has also revealed that its networks have been breached, though it claimed no customer data was compromised. The hackers did not only target U.S. companies but also stretched their reach to allied nations whose identities remain undisclosed.
Senator Mark Warner, chair of the Senate Intelligence Committee, called these attacks some of the most serious he's seen. He reported that the FBI had informed fewer than 150 people - mostly in Washington - whose communications were compromised. Some telecom companies are still working to get the attackers out of their networks, showing just how persistent these intrusions are.
Techniques and Long-Term Goals
Salt Typhoon uses advanced tactics to infiltrate systems and maintain long-term access. They include vulnerability exploitation in common devices like Cisco routers and Microsoft Exchange servers. Researchers also found that this group uses legitimate tools to carry out their malicious activities, hence making it challenging to be detected.
Since at least 2020, this group has targeted not only the U.S. but also nations such as Brazil, India, and Taiwan. Their primary focus remains on gathering intelligence from telecommunications networks, government systems, and military organizations.
To mitigate such attacks, the FBI and CISA have been offering technical support to victims. U.S. Cyber Command has amplified operations aimed at disrupting the ability of Chinese cyber actors globally and, consequently, reducing the incidence and impact of such attacks.
This has also raised fears about broader objectives, including possible disruption of Western infrastructure in case tensions over Taiwan or any other issue are to rise further. According to FBI Director Christopher Wray, "China's hacking capabilities are larger than those of any other nation and present a significant challenge to our nation's cybersecurity defenses.".
In response to the growing threats, the Senate has scheduled a classified briefing in December to discuss further measures. The meeting underlines the urgent need to strengthen cybersecurity across critical sectors.
While many countries actively engage in some form of warfare, the U.S. has a certain stance that China, in regard to cyberespionage, poses a significant threat. According to the United States cyber defense agency CISA, "China probably currently represents the broadest, most active, and persistent cyber espionage threat to U.S. Government and private-sector networks."
CISA further notes that cyberattacks based in China may also have an impact on U.S. oil and gas pipelines, as well as rail systems.
While this warning is just an overview, China is renowned for its highly advanced cyber operations. The infamous GhostNet spy system, which compromised more than 1,000 computers of military, political, economic, and diplomatic targets around the world, is largely believed to have been coordinated by the Chinese government. China was never formally blamed for the crime, though, for a number of political and legal reasons. The history of GhostNet is therefore still a mystery.
GhostNet first came to light when the office of the Dalai Lama in India invited a team of security researchers at the Munk Center for International Studies at the University of Toronto to check their computers for any indication of a hack. This prompted an inquiry that turned up a large cyberattack that had compromised 1,295 systems over the course of two years in 103 nations. The Munk Center and Information Warfare Monitor analysts released a thorough analysis in 2009 that provided insight into the extensive spying operation they called "GhostNet."
GhostNet distributed malware via emails with attachments and suspicious links. Once the malware was successfully downloaded on the victim’s system, it would take complete access to the computers, which further enabled hackers to search for and download files, and even control the victim’s external devices like webcams and microphones.
Around 30% percent of the victims of GhostNet were of high-profile, such as foreign ministries of several nations in Southeast Asia, South Asia and Europe. Also, several international organizations were targeted, like ASEAN, SAARC, the Asian Development Bank, news organizations, and computers of NATO headquarters.
Researchers from GhostNet were successful in locating and connecting to the espionage network's command servers. Hainan Island in China was linked to a number of IP addresses that the attackers used to communicate with the compromised PCs. Four control servers in total were found by the investigation, three of which were in China. The fourth server was situated at an American web hosting business. Furthermore, five of the six detected command servers were found in mainland China, while the sixth was found in Hong Kong.
According to researchers, China is amongst the most obvious operators behind GhostNet, however, their reports did not directly point at the country since they were unable to provide any concrete proof of the Chinese government’s involvement. They noted that other nations could also be behind the attacks.
The cyber-threat group has recently been targeting two subsidiaries of a major Asian conglomerate, which apparently specializes in materials and composites. The attack follows right after another distinct campaign against the Asian material sector.
The APT attack was seen utilizing the Winnkit backdoor, Mimikatz, and several tools for credential dumping, screen capture, process hollowing, SQL querying, memory dumping (ForkPlayground), and proxy configuration.
In one of the instances, Symantec discovered a material research organization in Asia that was being targeted by a previously unidentified threat group named ‘Clasiopa,’ which does not seem to be linked to the APTs.
It is believed that Clasiopa acquired access to the targeted organization by brute forcing public facing servers and using a variety of post-exploitation tools like Atharvan remote access trojan (RAT), which is a modified version of the Lilith RAT, the Thumbsender hacking tool, and a custom proxy tool. The threat actor, according to Symantec, utilized the backdoors to compile lists of files and exfiltrate them, deleted logs, set a scheduled task to list file names, and verified the IP addresses of the compromised machines in an effort to disable endpoint protections.
Moreover, it appears that Clasiopa used authorised software from Agile and Domino throughout the attack, but it is still unclear whether the attackers actually deployed the tools or simply abused the existing installations. Apparently Atharvan backdoor is able to download arbitrary files from the server, execute files, and configure communications through the C&C server, all based on the commands received from its operators.
Adding to this, the Atharvan RAT can terminate or restart programs, send remote commands and PowerShell scripts, as well as terminate and uninstall itself. Further analysis on Atharvan revealed a Hindi mutex and a password, suggesting that Clasiopa could be based in India, although Symantec says that these could be some of the false flags planted by the threat group to muddle with the investigation.
An earlier anonymous backdoor malware, called PortDoor, is probably being used by Chinese APT (advanced persistent threat) hackers to attack Russian defense system, according to reports. Cybersecurity firm 'Cybereason Nocturnus' looked into hackers specifically targeting Rubin Design Bureau, an organization that builds submarines for Russian Navy Federation. The main target was director general named Igor Vladimirovich, who received a phishing mail, say experts. The attack started with "Royalroad weoponizer" aka RTF exploit builder/8.t Dropper, which, according to cybersecurity experts, is a tool used by Chinese APT's to orchestrate their attacks, like Tick, Tonto Team and TA428.