Silk Typhoon hackers now target IT supply chains to breach networks

Microsoft warns that Chinese cyber-espionage threat group 'Silk Typhoon' has shifted its tactics, now targeting remote management tools and cloud services in supply chain attacks that give them access to downstream customers.

The tech giant has confirmed breaches across multiple industries, including government, IT services, healthcare, defense, education, NGOs, and energy.

"They [Silk Typhoon] exploit unpatched applications that allow them to elevate their access in targeted organizations and conduct further malicious activities," reads Microsoft's report.

"After successfully compromising a victim, Silk Typhoon uses the stolen keys and credentials to infiltrate customer networks where they can then abuse a variety of deployed applications, including Microsoft services and others, to achieve their espionage objectives."

Silk Typhoon storms IT supply chains

Silk Typhoon is a Chinese state-sponsored espionage group known for hacking the U.S. Office of Foreign Assets Control (OFAC) office in early December 2024 and stealing data from the Committee on Foreign Investment in the United States (CFIUS).

Microsoft reports that Silk Typhoon switched tactics around that period, abusing stolen API keys and compromised credentials for IT providers, identity management, privileged access management, and RMM solutions, which are then used to access downstream customer networks and data.

Microsoft says the attackers scan GitHub repositories and other public resources to locate leaked authentication keys or credentials and then use them to breach environments. The threat actors are also known for using password spray attacks to gain access to valid credentials.

Previously, the threat actors were primarily leveraging zero-day and n-day flaws in public-facing edge devices to gain initial access, plant web shells, and then move laterally via compromised VPNs and RDPs.

Switching from organization-level breaches to MSP-level hacks allows the attackers to move within cloud environments, stealing Active Directory sync credentials (AADConnect), and abusing OAuth applications for a much stealthier attack.

The threat actors no longer rely on malware and web shells, with Silk Typhoon now exploiting cloud apps to steal data and then clear logs, leaving only a minimal trace behind.

According to Microsoft's observations, Silk Typhoon continues to exploit vulnerabilities alongside its new tactics, sometimes as zero days, for initial access.

Most recently, the threat group was observed exploiting a critical Ivanti Pulse Connect VPN privilege escalation flaw (CVE-2025-0282) as a zero-day to breach corporate networks.

Earlier, in 2024, Silk Typhoon exploited CVE-2024-3400, a command injection vulnerability in Palo Alto Networks GlobalProtect, and CVE-2023-3519, a remote code execution flaw in Citrix NetScaler ADC and NetScaler Gateway.

Microsoft says the threat actors have created a "CovertNetwork" consisting of compromised Cyberoam appliances, Zyxel routers, and QNAP devices, which are used to launch attacks and obfuscate malicious activities.

Microsoft has listed updated indicators of compromise and detection rules that reflect Silk Typhoon's latest shift in tactics at the bottom of its report, and defenders are recommended to add the available information to their security tools to detect and block any attacks timely.