Chinese hackers spent 18 months inside Microsoft 365 before anyone noticed

A China-linked espionage group lived inside corporate cloud accounts for a year and a half by stealing trust instead of breaking in. The security checks built t

Martin Cid Magazine
Chinese APT deploys new malware to keep access to hacked networks

A Chinese espionage group tracked as UNC5221 has been accessing Microsoft 365 environments using the Brickstorm backdoor and previously undocumented malware named Plenet and AgentPSD.

BleepingComputer

UNC5221, a Chinese APT, isn't relying on one backdoor. They're building an "access portfolio" with new malware like Brickstorm and Plenet, exploiting zero-days and edge devices to maintain persistent access for over 18 months. This multi-malware strategy allows re-breaches, turning incident response into a resource drain. Discover their tactics and the real impact.

https://www.tpp.blog/r27bx1d

#cybersecurity #unc5221 #brickstorm

🤖 This post was AI-generated.

Chinese APT Exploits New Malware to Prolong Network Access

A Chinese-linked espionage group, tracked as UNC5221 or VerdantBamboo, exploited new malware to secretly maintain access to US networks for over 18 months, evading detection by blending in with legitimate traffic. The attackers used a sophisticated backdoor called Brickstorm to prolong their stay undetected.

https://osintsights.com/chinese-apt-exploits-new-malware-to-prolong-network-access?utm_source=mastodon&utm_medium=social

#ChineseApt #MalwareOperations #NationState #Unc5221 #Verdantbamboo

Chinese APT Exploits New Malware to Prolong Network Access

Learn how Chinese APT group UNC5221 uses new malware to prolong network access and evade detection, and take steps to protect your organization now.

OSINTSights
Threats to the Defense Industrial Base | Google Cloud Blog

The defense sector faces a relentless barrage of operations conducted by state-sponsored actors and criminal groups.

Google Cloud Blog
📢 BRICKSTORM : une backdoor attribuée à UNC5221 cible des organisations américaines via appliances réseau et zero-days
📝 Selon PolySwarm (rapport Threats and Vulne...
📖 cyberveille : https://cyberveille.ch/posts/2025-10-05-brickstorm-une-backdoor-attribuee-a-unc5221-cible-des-organisations-americaines-via-appliances-reseau-et-zero-days/
🌐 source : https://blog.polyswarm.io/brickstorm-targets-u.s.-tech-and-legal-sectors-with-stealthy-espionage
#BRICKSTORM #UNC5221 #Cyberveille
BRICKSTORM : une backdoor attribuée à UNC5221 cible des organisations américaines via appliances réseau et zero-days

Selon PolySwarm (rapport Threats and Vulnerabilities), la backdoor BRICKSTORM, attribuée au cluster de menace UNC5221 (nexus Chine), mène depuis mars 2025 une campagne d’espionnage contre des organisations américaines des secteurs juridique, SaaS, BPO et technologique. L’opération met l’accent sur le vol de propriété intellectuelle et d’emails sensibles, avec une durée de présence moyenne de 393 jours. Le groupe cible des appliances réseau dépourvues d’EDR, exploite des vulnérabilités zero-day et emploie des techniques anti-forensiques. Il s’appuie sur les composants BRICKSTEAL (récolte d’identifiants) et SLAYSTYLE (web shell) ainsi que sur des identifiants compromis pour la mouvement latéral et l’exfiltration.

CyberVeille

Google China-linked hackers (#UNC5221) are targeting US SaaS and tech firms using the new BRICKSTORM malware, exploiting zero-day flaws, Mandiant has found.

Read: https://hackread.com/china-hackers-hit-us-tech-firms-brickstorm-malware/

#CyberSecurity #BRICKSTORM #0Day #InfoSec #APT #CyberAttack

China-Linked Hackers Hit US Tech Firms with BRICKSTORM Malware

Follow us on Bluesky, Twitter (X), Mastodon and Facebook at @Hackread

Hackread - Latest Cybersecurity, Hacking News, Tech, AI & Crypto
#Google warns #China-linked spies lurking in 'numerous' #enterprises
Since March, Google's #Mandiant #incidentresponse team have responded to these #UNC5221-related break-ins across legal, Software as a Service (SaaS) providers, Business Process Outsourcers (BPOs), and technology companies. They were fount to deploy #backdoors, providing access for their long-term IP and other sensitive data stealing missions, all the while remaining undetected on average for 393 days!
https://www.theregister.com/2025/09/24/google_china_spy_report/
Google warns China-linked spies lurking in 'numerous' enterprises since March

: Mandiant CTO anticipates 'hearing about this campaign for the next one to two years'

The Register
Another BRICKSTORM: Stealthy Backdoor Enabling Espionage into Tech and Legal Sectors
#BRICKSTORM #UNC5221
https://cloud.google.com/blog/topics/threat-intelligence/brickstorm-espionage-campaign
Another BRICKSTORM: Stealthy Backdoor Enabling Espionage into Tech and Legal Sectors | Google Cloud Blog

BRICKSTORM is a stealthy backdoor used by suspected China-nexus actors for long-term espionage.

Google Cloud Blog
China-linked APT UNC5221 started exploiting Ivanti EPMM flaws shortly after their disclosure

China-linked APT exploit Ivanti EPMM flaws to target critical sectors across Europe, North America, and Asia-Pacific, according to EclecticIQ.

Security Affairs