Hackers associated with the Russian threat group Sandworm have been targeting system administrators and IT professionals through fake job offers since at least May. A report from the Ukrainian Computer Emergency Response Team (CERT) details a social engineering campaign attributed to UAC-0145, which is believed to be a sub-cluster of Sandworm (APT44). In the campaign, the threat actor targets victims while posing as IT companies and recruiters. The agency says that the attacker studies the targets' resumes uploaded on job sites and then initiates direct contact. Conversations are then moved to Telegram to arrange a video interview over Zoom. During the interview, which is conducted in English, the candidates receive mock technical assignments that require them to connect to a corporate VPN. In one case that CERT-UA observed, the attacker impersonated the international IT firm Sopra Steria using seemingly legitimate email addresses similar to the company’s office in Bulgaria.
FBI seizes QScan and QTRouter, China-linked platforms used to hide intrusions and target U.S. critical infrastructure. The U.S. Department of Justice and the FBI have seized two platforms, QScan and QTRouter, used by a China-linked group to hide cyberattacks and target critical infrastructure. The operation matters because it shows how state-backed actors no longer need to build every part of an attack from scratch: they can rely on shared scanning tools, compromised devices, commercial proxy services, and rented servers. U.S. authorities attribute the activity to a group known as QTFY, which they say operated through the China-based company Nanjing Xinjiuwei Network Technology Company. According to the Justice Department, the group offered hacking services to paying clients that included China’s Ministry of State Security and the People’s Liberation Army. “The Justice Department and FBI announced court-authorized domain seizures today to deny malicious cyber actors access to two complementary hacking platforms known as “QScan” and “QTRouter,” used to target U.S. critical infrastructure and other sensitive networks. As described in court documents unsealed in the Southern District of California, a People’s Republic of China (PRC) state-sponsored group known as “QTFY,” employed by China-based Nanjing Xinjiuwei Network Technology Company (南京鑫玖维网络科技有限公司), created and operated QScan and QTRouter.” reads the press release published by DoJ. According to the Justice Department, QTFY targeted NASA, the Federal Reserve, the Departments of Energy, Justice, and Health and Human Services, the National Institutes of Health, and the U.S. Senate. Those are not random targets caught in a broad scan. QScan and QTRouter had different jobs. QScan searched the internet for vulnerable devices and automatically infected thousands of exposed Internet of Things devices. Those compromised routers, cameras, appliances, and other connected systems were then added to QTRouter, a proxy network used to route malicious traffic through systems located outside China. That approach makes attribution and blocking harder. A victim may see an attack coming from what appears to be a local router, a legitimate commercial proxy, or a virtual private server rented in another country. Blocking traffic by country or IP address becomes far less useful when the attacker is borrowing the identity and location of other people’s devices. “QScan scans and automatically infects thousands of “internet-of-things” (IoT) devices worldwide, which are then added to the QTRouter network of QTFY-controlled devices. QTRouter consists of these compromised IoT devices, as well as commercial proxy service devices and leased virtual private servers.” continues DoJ. “QTRouter then serves as an “obfuscation network” – meaning it allows QTFY and other malicious cyber actors to conceal the PRC-origin of their computer intrusion activities because the malicious communications appear to originate from computers (such as those compromised by QScan) that are outside of the PRC and may even be local to the targeted networks.” The government did not merely take down a website. The seized domains were hard-coded into QScan and QTRouter and used for core functions such as authentication and command-and-control communication. By taking control of those domains through a court order, the FBI made the malware platforms unable to operate as intended. This is a useful example of technical disruption rather than simple attribution. Publicly naming a group matters, but it does not stop an operator who already has access to vulnerable devices and a working relay network. Taking away the infrastructure they need to manage that network is more disruptive, at least until they rebuild it. “Because the seized domains were hard-coded into both the QScan and QTRouter malware and used for essential tasks such as communication and authentication, the court-authorized seizures made QScan and QTRouter inoperable.” DoJ states. The broader operation looks like an industrial service model. QTFY allegedly used QScan to map targets, identify weaknesses, and compromise devices; it then used QTRouter and other proxy layers to hide where the activity actually came from. Lumen’s Black Lotus Labs described the group as a “digital quartermaster,” meaning it supplied infrastructure and services that could support multiple operations at the same time. “To support its primary objectives, the quartermaster runs a secondary, completely decoupled target profiling utility called “QScan.” While the core proxy network focuses on managing stateful session paths, the QScan framework operates as the front-end scout.” reads a report published by Lumen. “The operations of this quartermaster demonstrate the high degree of industrialization occurring within China-nexus cyber operations. By shifting away from fragmented, ad hoc setups and toward shared multi-tenant utility networks, state-sponsored actors can execute complex campaigns with a high degree of anonymity and speed, and at a global scale.” The group reportedly exploited both old and newly disclosed vulnerabilities in widely deployed products, including Fortinet SSL-VPN, Citrix ADC, Microsoft Exchange, F5 BIG-IP, Apache Log4j, Atlassian Confluence, Check Point gateways, CrushFTP, Ivanti appliances, and BeyondTrust Remote Support. This is not a reminder that organisations need magic detection. It is a reminder that old vulnerabilities remain useful because somebody, somewhere, will still leave them unpatched. The attack chain also included web shells, remote-access trojans, stolen or legitimate credentials, and compromised IoT devices used as nearby relay points. That combination allows an attacker to blend into normal-looking traffic and avoids the obvious infrastructure that defenders have learned to block. A hostile connection that looks like a local consumer router is still hostile; it just has better camouflage. This seizure follows earlier FBI actions against China-linked botnets. In 2025, the FBI removed PlugX malware from more than 4,000 infected U.S. computers linked to Mustang Panda. In 2024, it disrupted a botnet of hundreds of thousands of IoT devices associated with Flax Typhoon, while in 2023 it acted against a Volt Typhoon botnet used to conceal activity targeting U.S. and foreign critical infrastructure. “For defenders, the operational lesson is straightforward. Inventory internet-facing assets, patch known vulnerabilities quickly, remove unsupported devices, monitor unusual outbound proxy traffic, and do not assume that an IP address tells you who is behind an attack. The same applies to IoT equipment: a router, camera, network appliance, or smart device left exposed and unmanaged can become part of someone else’s attack platform. “This disruption announced today is among a series of court-authorized technical operations against indiscriminate hacking activities by the PRC.” concludes DoJ. Follow me on Twitter: @securityaffairs and Facebook and Mastodon Pierluigi Paganini (SecurityAffairs – hacking, QTRouter)
North Korea-linked hackers hid a backdoor inside HAProxy, masking C2 traffic and stealing data while keeping the load balancer working normally. North Korean-linked hackers found a genuinely clever hiding spot for their malware: inside the actual source code of HAProxy, the load balancing software running at the edge of two South Korean companies’ networks. Rapid7’s research documents a previously undocumented Linux toolkit hitting South Korea’s automotive and media sectors, and the depth of integration here goes well beyond a typical backdoor bolted onto a system. “A new Linux toolkit, identified by Rapid7 Labs, has been targeting organizations across South Korea’s automotive and media industries with minimal detection. The campaign made use of a HAProxy instance named “ted backdoor”, alongside trojanized versions of crond, agetty, atd, sshd, and polkitd.” reads the report published by Rapid7. “This previously undocumented framework enabled threat actors to execute remote commands on compromised servers, inject malicious scripts into web traffic, perform credential harvesting, and engage in long-term surveillance.” The implant, which Rapid7 calls the “ted backdoor” based on debug strings the attackers left behind, isn’t a separate process running alongside HAProxy. It’s compiled directly into HAProxy’s own source code as a custom plugin, using the software’s native filter API, internal memory management, and event scheduler to intercept HTTP traffic while completely legitimate load balancing keeps running normally on top of it. “The standout feature of this toolkit is its depth of integration with the target environment. The ted backdoor is compiled as part of the victim’s existing HAProxy version 2.8.12.” continues the report. “It uses its native filter API, internal memory pools, event scheduler, and process management infrastructure to intercept traffic and hide from monitoring, while genuine load balancing traffic operates as expected.” Rapid7 explains, which is really the whole thesis of why this backdoor is so hard to spot: it’s not an addition to the software, it’s woven into it. The backdoor receives commands through a surprisingly simple trick. The attackers send a request for a fake image at /favorite_list_2x_m500_ico.jpg. This switches the HAProxy filter into command-and-control mode. The malware then saves the command in a named pipe and removes traces of the request from HAProxy’s internal counters. It also clears the forwarding buffers, so the request never reaches the backend server. The command ends at the load balancer, leaving nothing in the application logs to show that it happened. This ability to erase its own traces makes the backdoor very different from a normal web shell. The C2 requests never reach the backend server and are also removed from HAProxy’s statistics. As a result, neither the application logs nor HAProxy’s connection logs show that the attack happened. A security team checking the logs could find nothing suspicious because the backdoor has already erased the evidence. Beyond remote command execution, the backdoor can quietly inject malicious scripts or entirely swap out page content for specific victims matched by IP address, browser fingerprint, or even a hidden authentication credential smuggled inside the Accept-Language header, effectively turning a company’s own load balancer into a watering hole against its own visitors. It also hooks response bodies carefully enough to hide the size difference caused by injected content, stripping the header that would let a browser notice the byte-range mismatch. That’s a level of protocol-level care that suggests real HAProxy internals expertise, not a quick copy-paste job. The main backdoor also comes with a separate toolkit that modifies common Linux system daemons such as crond, agetty, atd, and sshd. These programs continue to work normally but also carry malicious features. One component acts as an SSH keylogger. It captures passwords that administrators enter in plain text and quietly records them. Another tool, called curlRAT, contacts a remote server every 12 hours by default, or every 30 seconds when the attacker enables its fast-poll mode. curlRAT also checks whether the system runs inside a virtual machine. If it does not find the expected signs, it refuses to run. This behavior suggests the attackers designed the malware to avoid sandboxes and other analysis environments. Attribution here sits at medium confidence, and Rapid7 is upfront about the limits of what the evidence actually shows. The targeting pattern, simple XOR-based encryption, a custom substitution cipher, and command-server infrastructure already linked to APT37 by other threat intelligence feeds all point toward North Korean state involvement, with some technical overlap also drawing comparisons to a concurrent Lazarus Group campaign against South Korean media sites. “Further evidence is necessary to make a more definitive assessment. Moreover, the presence of ngx_* prefixed routines within the ted backdoor suggest code reused from an nginx backdoor. The ngx_* prefixed routines were observed during the latest Funnull campaign, where (similar to our case) a custom nginx filter was registered to hook HTTP traffic, and simple XOR encryption was applied to the configuration file.” Rapid7 states. “However, other than a similar naming convention, no significant code-level overlaps exist to support a stronger linkage.” If your organization runs HAProxy, or really any edge component handling SSL termination and traffic routing, the practical lesson here is uncomfortable but simple: that software deserves the same scrutiny as your actual application servers, not less. The Hacker News confirmed in early September that the specific command domains used in this campaign have already gone dark, returning no DNS records at all, which is useful for reviewing historical logs but does nothing to stop whatever comes next from the same operators. Checking a load balancer’s own logs isn’t enough anymore when the backdoor’s entire design goal is making sure those logs never see it in the first place. “ted backdoor and curlRAT were designed to persist during long-term espionage operations with the ability to steal cookie sessions, credentials, redirect selected users, conduct drive-by download attacks, and hide evidence of the tampered page to a specific range of IPs to evade detection.” concludes the report. “Defenders should treat any edge component managing user traffic, SSL, or runtime modules with the same strict security standards as their main application servers. Relying on the component’s own logs is not enough; securing these systems requires independent network correlation, memory behavioral analysis, and binary integrity checks.” Follow me on Twitter: @securityaffairs and Facebook and Mastodon Pierluigi Paganini (SecurityAffairs – hacking, North Korea)
Three threat groups are exploiting two Cisco FMC flaws to steal credentials, gain root access and deploy Qilin ransomware. Cisco Talos says three separate threat groups are exploiting two recently patched Secure Firewall Management Center (FMC) flaws. The main target is CVE-2026-20079, a critical authentication bypass that lets unauthenticated attackers remotely bypass security controls, run scripts and potentially gain root access. Attackers also exploit CVE-2026-20316 to access sensitive data through a low-privilege account. The second flaw can be chained with other FMC vulnerabilities to increase privileges. Cisco linked the attacks to ransomware operations, including Qilin, as well as state-sponsored activity. “Talos’ analysis illustrates three clusters of post-compromise activity on FMC instances associated with state-sponsored and crimeware threat actors, as described below.” reads the advisory. “The first cluster which we track as UAT-12197, involves the exploitation of CVE-2026-20079, leading to the deployment of web shells, a Java Archive (JAR)-based command executor, and credential exfiltration.” Talos identified three attack clusters targeting Cisco Secure Firewall Management Center (FMC). The first cluster deploys JSP-based web shells and custom command executors into Tomcat webroot directories to query internal databases and harvest user authentication data and credentials. “This cluster of activity involved the successful exploitation of CVE-2026-20079 and the subsequent placement of a malicious web shell in the CSM Tomcat webroot directory.” reads the report. “The web shell is JSP-based and Base64 decodes a parameter labelled “F6C1F0E7”, consisting of the class name to load in the JAVA process:” The second cluster, attributed to the advanced persistent threat actor UAT-11823 with tooling overlapping Sandworm, establishes Netcat reverse shells, harvests device configurations, and installs the modular ELF malware “Cyclops Blink” for persistent access, DNS over HTTPS resolution, and packet sniffing. “The threat actor obtained initial access to compromised systems by either exploiting CVE-2026-20079 or via static credentials.” Talos states. “After obtaining access, UAT-11823 subsequently updated the “license.tmp” file on disk (using Makeself) with a malicious copy to establish a Netcat-based reverse shell to their own command-and-control (C2) server:” The third cluster involves Qilin ransomware operators (UAT-11988) who use static credentials for initial access, perform extensive domain reconnaissance, deploy SOCKS proxies and reverse-SSH tunnels, and execute AV killers before deploying ransomware. “Once extensive reconnaissance was completed, the threat actor attempted to establish persistent network access into the victim organization using a Python SOCKS5 proxy (socks5.py) and a reverse-SSH tunnel from the FMC back to the attacker’s own remote host. The following ports were forwarded: LDPA (389), LDAPS (636), Kerberos (88), SMB (445), NETBIOS (135), and WinRM (5985).” concludes the report. “The threat actor conducted extensive probing of endpoints in the victim’s environment, deployed open-source tooling such as impacket, Invoke-TheHash, and custom-made AV killers — all followed by the deployment of the Qilin ransomware on selected endpoints.” Cisco strongly urges customers to immediately apply released hotfixes and update detection rules using the provided Snort SIDs while awaiting upcoming comprehensive security hardening updates. CISA added CVE-2026-20079 to its KEV catalog, requiring U.S. federal agencies to patch it by September 12, 2026. CVE-2026-20316 was added in late July. Follow me on Twitter: @securityaffairs and Facebook and Mastodon Pierluigi Paganini (SecurityAffairs – hacking, Cisco FMC)
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