Chinese Hackers Target Linux Systems Using SNOWLIGHT Malware and VShell Tool
Vulnerabilities mentionedAll →
| CVE | Vulnerability | CVSS | EPSS | Flags | Affected | Exposure | Published |
|---|---|---|---|---|---|---|---|
| CVE-2024-8190 | OS Command Injection RCE in Ivanti Cloud Services Appliance 4.6 Ivanti Cloud Services Appliance versions 4.6 Patch 518 and before contain an OS command injection flaw (CWE-78) that allows a remote, authenticated attacker to achieve remote code execution. The attacker must already hold administrator-level privileges on the appliance, and exploitation is triggered by sending crafted input to the appliance over the network. Successful exploitation yields arbitrary command execution on the CSA, and related reporting indicates nation-state actors have been exploiting Ivanti CSA flaws for network infiltration, including attacks on French government and telecom targets. Only organizations still running CSA 4.6.x are affected, and that product line has reached end-of-life and will not receive further security updates. The vulnerability was added to CISA's Known Exploited Vulnerabilities catalog on 2024-09-13 and carries a very high EPSS score (88.5%, 100th percentile), signaling confirmed and likely ongoing exploitation in the wild. Do: Because CSA 4.6.x has reached end-of-life, remove CSA 4.6.x from service or migrate to the supported 5.0.x line, as future 4.6.x flaws are unlikely to receive fixes. Given confirmed nation-state exploitation, hunt for signs of compromise such as unexpected admin sessions, processes, or network tunnels, and restrict internet exposure of any remaining 4.6.x appliances in the interim. | 7.2 | 89% | KEV |
| moderateroughly 1,000–2,000 internet-exposed CSA appliances (public internet scan counts) | |
| CVE-2024-8963 | Unauthenticated Path Traversal in Ivanti Cloud Services Appliance CVE-2024-8963 is a path traversal vulnerability (CWE-22) in the Ivanti Cloud Services Appliance (CSA), a virtual appliance used to remotely manage Ivanti Endpoint Manager environments. A remote, unauthenticated attacker can send crafted requests containing directory traversal sequences to reach restricted functionality without any credentials. Successful exploitation grants access to restricted (including administrative) functions on the appliance, and public reporting indicates it has been chained with other CSA zero-day flaws by nation-state attackers to infiltrate networks. All CSA 4.6.x releases before Patch 519 are affected, and the 4.6.x product line has reached end-of-life, meaning future 4.6.x vulnerabilities will not receive fixes. Exploitation is confirmed in the wild: CISA added it to the Known Exploited Vulnerabilities catalog on 2024-09-19, and multiple outlets report Chinese-linked actors exploiting CSA zero-days against French government, telecom and other critical-infrastructure targets. Do: Upgrade CSA 4.6.x to Patch 519 or later, or move to the supported 5.0.x line; because 4.6.x is end-of-life, CISA urges removing CSA 4.6.x from service or migrating to 5.0.x rather than relying on future 4.6.x patches. Until patched, restrict or remove internet exposure of CSA appliances and review logs for unauthenticated access to restricted functionality, since this flaw is being chained with other CSA vulnerabilities in targeted intrusions. | 9.1 | 99% | KEV |
| moderate≈1,000–2,000 internet-exposed CSA appliances (order of magnitude; installed base larger if internal-only deployments are counted) | |
| CVE-2024-9380 | OS Command Injection RCE in Ivanti Cloud Services Appliance Admin Console CVE-2024-9380 is an OS command injection flaw (CWE-77/CWE-78) in the admin web console of Ivanti Cloud Services Appliance (CSA), fixed in version 5.0.2. A remote attacker who is already authenticated with administrative privileges can inject arbitrary operating system commands through the console, which the appliance then executes. Successful exploitation yields remote code execution with high impact on confidentiality, integrity, and availability (CVSS 3.1: 7.2). All CSA releases before 5.0.2 are affected, and the widely deployed 4.6.x line has reached End-of-Life, so EOL users must remove it from service or move to 5.0.x or later. The flaw was added to CISA's Known Exploited Vulnerabilities catalog on 2024-10-09, and contemporaneous reporting describes Chinese nation-state actors exploiting Ivanti CSA zero-days against French government and telecom targets, with a 63.2% EPSS probability of exploitation in the next 30 days (99th percentile). Do: Upgrade Ivanti CSA to 5.0.2 or later; if you are running the End-of-Life 4.6.x line, either remove it from service or migrate to the supported 5.0.x line, per CISA's KEV required action. Restrict exposure of the admin web console (do not leave it directly internet-facing) and verify whether your appliance was targeted. Given reported nation-state exploitation of CSA zero-days, review appliance logs and admin credentials for signs of compromise. | 7.2 | 63% | KEV |
| moderate≈ a few thousand internet-exposed CSA appliances; total installed base likely in the low tens of thousands | |
| CVE-2025-0282 | Unauthenticated RCE in Ivanti Connect Secure, Policy Secure, and ZTA Gateways CVE-2025-0282 is a stack-based buffer overflow (CWE-121) in Ivanti Connect Secure, Policy Secure, and ZTA Gateways, reachable by unauthenticated network input. An attacker can trigger it remotely by sending crafted, unauthenticated traffic to a vulnerable gateway, overwriting stack memory and gaining code execution under the appliance's context. Successful exploitation yields unauthenticated remote code execution on the device, giving the attacker control of the VPN/secure-access gateway and a foothold into the protected network. Organizations running any of the affected Ivanti secure-access products are exposed; the source data specifies no version ranges, so defenders should consult Ivanti's advisory for exact affected and fixed releases. The flaw is being actively exploited: it was added to CISA KEV on 2025-01-08 with known ransomware use, and EPSS assigns a 100% probability of exploitation within 30 days (100th percentile), despite no public PoC being known. Do: Apply the patched releases identified in Ivanti's advisory and follow CISA's required action: hunt for signs of compromise, remediate if indicators are found, and apply updates before returning any device to service. Because exploitation is active and ransomware use is known, treat any appliance that was internet-reachable before patching as potentially compromised (check integrity, rotate credentials). Exact fixed versions were not included in the source data, so verify the correct update path for your branch (including older Connect Secure/Policy Secure releases) against Ivanti's bulletin. | 9.0 | 100% | KEV ransomware PoC ×3 |
| largetens of thousands of internet-exposed appliances (likely 100,000+ total deployments including internal-only gateways) | |
| CVE-2025-22457 | Unauthenticated Stack Buffer Overflow RCE in Ivanti Connect Secure Ivanti Connect Secure, Policy Secure, and ZTA Gateways contain a stack-based buffer overflow (CWE-121) that can be triggered by a remote, unauthenticated attacker sending crafted input that overruns a fixed-size stack buffer on the affected gateway. Successful exploitation yields remote code execution on the appliance, giving an attacker control of an enterprise VPN or zero-trust access gateway and a foothold in the surrounding network. Any organization running the affected Ivanti gateway products is exposed, with impact concentrated among enterprises using these appliances for remote-access VPN and zero-trust network access. The vulnerability was added to CISA's KEV catalog on 2025-04-04 with known ransomware use, and its maximum EPSS score (100.0%, 100th percentile) signals near-certain exploitation pressure within 30 days. No public proof-of-concept is known, but confirmed in-the-wild exploitation makes this an actively abused, high-priority flaw. Do: Apply the mitigations required by CISA and update Connect Secure, Policy Secure, and ZTA Gateways to the patched releases designated in Ivanti's advisory, prioritizing internet-exposed VPN gateways. Given known ransomware use, review appliance and downstream logs for signs of compromise, and treat unpatched gateways as high risk given the 100th-percentile EPSS score. | 9.8 | 100% | KEV ransomware |
| largetens of thousands of deployed gateways, with on the order of 10k-100k internet-exposed appliances |
Full article764 words · extracted from thehackernews.com · click to collapse
The China-linked threat actor known as UNC5174 has been attributed to a new campaign that leverages a variant of a known malware dubbed SNOWLIGHT and a new open-source tool called VShell to infect Linux systems.
"Threat actors are increasingly using open source tools in their arsenals for cost-effectiveness and obfuscation to save money and, in this case, plausibly blend in with the pool of non-state-sponsored and often less technical adversaries (e.g., script kiddies), thereby making attribution even more difficult," Sysdig researcher Alessandra Rizzo said in a report shared with The Hacker News.
"This seems to hold especially true for this particular threat actor, who has been under the radar for the last year since being affiliated with the Chinese government."
UNC5174, also referred to as Uteus (or Uetus), was previously documented by Google-owned Mandiant as exploiting security flaws in Connectwise ScreenConnect and F5 BIG-IP software to deliver a C-based ELF downloader named SNOWLIGHT, which is designed to fetch a Golang tunneler dubbed GOHEAVY from infrastructure tied to a publicly available command-and-control (C2) framework known as SUPERSHELL.
Also deployed in the attacks was GOREVERSE, a publicly available reverse shell backdoor written in Golang that operates over Secure Shell (SSH).
The French National Agency for the Security of Information Systems (ANSSI), in its Cyber Threat Overview report for 2024 published last month, said it observed an attacker employing similar tradecraft as that of UNC5174 to weaponize security flaws in Ivanti Cloud Service Appliance (CSA) such as CVE-2024-8963, CVE-2024-9380, and CVE-2024-8190 to gain control and execute arbitrary code.
"Moderately sophisticated and discreet, this intrusion set is characterized by the use of intrusion tools largely available as open source and by the – already publicly reported – use of a rootkit code," the ANSSI said.
It's worth noting that both SNOWLIGHT and VShell are capable of targeting Apple macOS systems, with the latter distributed as a fake Cloudflare authenticator application as part of an as-yet-undetermined attack chain, according to an analysis of artifacts uploaded to VirusTotal from China in October 2024.
In the attack chain observed by Sysdig in late January 2025, the SNOWLIGHT malware acts as a dropper for a fileless, in-memory payload called VShell, a remote access trojan (RAT) widely used by Chinese-speaking cybercriminals. The initial access vector used for the attack is presently unknown.
Specifically, the initial access is used to execute a malicious bash script ("download_backd.sh") that deploys two binaries associated with SNOWLIGHT (dnsloger) and Sliver (system_worker), both of which are used to set up persistence and establish communications with a C2 server.
The final stage of the attack delivers VShell via SNOWLIGHT by means of a specially crafted request to the C2 server, thereby enabling remote control and further post-compromise exploitation.
"[VShell] acts as a RAT (Remote Access Trojan), allowing its abusers to execute arbitrary commands and download or upload files," Rizzo said. "SNOWLIGHT and VShell pose a significant risk to organizations due to their stealthy and sophisticated techniques," Sysdig said. "This is evidenced by the employment of WebSockets for command-and-control, as well as the fileless VShell payload."
The disclosure comes as TeamT5 revealed that a China-nexus hacking group likely exploited security flaws in Ivanti appliances (CVE-2025-0282 and CVE-2025-22457) to gain initial access and deploy the SPAWNCHIMERA malware.
The attacks, the Taiwanese cybersecurity company said, targeted a multitude of sectors spanning nearly 20 different countries such as Austria, Australia, France, Spain, Japan, South Korea, Netherlands, Singapore, Taiwan, the United Arab Emirates, the United Kingdom, and the United States.
The findings also dovetail with accusations from China that the U.S. National Security Agency (NSA) launched "advanced" cyber attacks during the Asian Winter Games in February, pointing fingers at three NSA agents for repeated attacks on China's critical information infrastructure as well as against Huawei.
According to the National Computer Virus Emergency Response Center (CVERC), the U.S. is alleged to be behind more than 170,000 cyber attacks between January 26 and February 14, 2025, followed by Singapore, the Netherlands, Germany, and South Korea. In all, the Games' information systems were targeted by 270,167 attacks from abroad.
"At the ninth Asian Winter Games, the U.S. government conducted cyberattacks on the information systems of the Games and the critical information infrastructure in Heilongjiang," Foreign Ministry Spokesperson Lin Jian said. "This move is egregious for it severely endangers the security of China's critical information infrastructure, national defense, finance, society, and production as well as its citizens' personal information."
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Text extracted automatically; images, tables and formatting may be missing. Original: https://thehackernews.com/2025/04/chinese-hackers-target-linux-systems.html