Thousands of ASUS routers are being hijacked in a state-sponsored cyber espionage campaign
Researchers believe that Operation WrtHug is being carried out by Chinese state-sponsored hackers
Thousands of ASUS routers around the world have been hijacked in a sophisticated campaign believed to be backed by China.
According to SecurityScorecard’s Strike threat intelligence team, the WrtHug campaign leverages the proprietary AiCloud service with Nth day vulnerabilities in order to gain high privileges on end-of-life ASUS WRT routers.
The pattern of attacks and the severity of the vulnerabilities indicate potential command injection capabilities, if not root-level privileges, researchers warned.
“Operation WrtHug is a case study in how nation-state actors are embedding themselves in consumer infrastructure to build stealthy, resilient, global espionage networks,” said Gilad Maizles, security researcher at SecurityScorecard.
“The deliberate targeting of end-of-life ASUS devices by compromising proprietary applications and services such as AiCloud, reflect growing strategic interest in SOHO devices. This shows us the willingness of threat actors to specialize in targeting them as reliable staging points.”
The campaign currently appears to be affecting around 50,000 compromised devices around the world, particularly in Taiwan, the US, and Russia, with more victims in some other Southeast Asian and European countries.
All the hijacked routers share a unique, self-signed TLS certificate with a 100-year expiration date - unusually long, researchers noted, and a critical indicator of compromise that points to a level of coordination reflecting careful and calculated espionage.
It was this certificate that first alerted the team to the campaign.
Six flaws underpin the ASUS espionage campaign
The attackers have been leveraging six distinct vulnerabilities for the campaign.
CVE-2023-41345, CVE-2023-41346, CVE-2023-41347, and CVE-2023-41348, all nearly two years old, enable attackers to perform direct OS command injection on ASUS WRT devices using insufficient filtering related to token modules. They're associated with the command injection vulnerability CVE-2023-39780.
Meanwhile, CVE-2024-12912 is an arbitrary command execution vulnerability and CVE-2025-2492 is an improper authentication control vulnerability that can lead to unauthorized function execution via a crafted request.
All are known and have officially been patched - which is why it's mostly end-of-life devices being targeted.
According to researchers, the targeted devices, methods, and timing mirror previous intrusion campaigns that have been linked to China - the LapDogs ORB, for example, recently uncovered by the Strike team.
Some of the vulnerabilities are tied to another ongoing suspected China-linked ORB operation known as AyySSHush, reported to be targeting ASUS devices earlier this year.
The team said it spotted seven IPs with signs of compromise in both Operation WrtHug and AyySSHush, suggesting either a single, evolving campaign or coordination between the two groups.
"These campaigns have demonstrated a clear evolution in attacker methodology. Persistent, resourced hackers are moving beyond simple brute-force attacks to multi-stage infections that exploit a variety of vulnerabilities," said the team.
"By chaining command injections and authentication bypasses, threat actors have managed to deploy persistent backdoors via SSH, often abusing legitimate router features to ensure their presence survives reboots or firmware updates."
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