Increased Cloud Attacks in Singapore Highlight Need for Data-Centric Security

The UNC5221 activity cluster, attributed to suspected Chinese hackers, has been using the BRICKSTORM malware in long-term espionage operations against U.S. organizations in the technology, legal, SaaS, and BPO sectors. The malware, a Go-based backdoor, has been active for over a year, with an average dwell time of 393 days. It has been used to steal data from various sectors, including SaaS providers and BPOs. The attackers exploit vulnerabilities in edge devices and use anti-forensics techniques to avoid detection. The malware serves multiple functions, including web server, file manipulation, dropper, SOCKS relay, and shell command execution. It targets appliances without EDR support, such as VMware vCenter/ESXi, and uses legitimate traffic to mask its C2 communications. The attackers aim to exfiltrate emails and maintain stealth through various tactics, including removing the malware post-operation to hinder forensic investigations. The attackers use a malicious Java Servlet Filter (BRICKSTEAL) on vCenter to capture credentials, and clone Windows Server VMs to extract secrets. The stolen credentials are used for lateral movement and persistence, including enabling SSH on ESXi and modifying startup scripts. The malware exfiltrates emails via Microsoft Entra ID Enterprise Apps, utilizing its SOCKS proxy to tunnel into internal systems and code repositories. UNC5221 focuses on developers, administrators, and individuals tied to China's economic and security interests. Mandiant has released a free scanner script to help defenders detect BRICKSTORM. The BRICKSTORM backdoor is under active development, with a variant featuring a delay timer for C2 communication. The attackers have exploited Ivanti Connect Secure zero-day vulnerabilities (CVE-2023-46805 and CVE-2024-21887) for initial access. The attackers have used a custom dropper to install a malicious Java Servlet filter (BRICKSTEAL) in memory, avoiding detection. The attackers have modified init.d, rc.local, or systemd files to ensure persistence on appliances. The attackers have targeted Windows environments in Europe since at least November 2022. The attackers have been linked to other related Chinese threat actors besides UNC5221. The campaign has been monitored by Mandiant since March 2025. The attackers have targeted downstream customers of compromised SaaS providers. The attackers are believed to be analyzing stolen source code to identify zero-day vulnerabilities in enterprise technologies. The attackers use a delay timer to lie dormant on infected systems until a hard-coded date. The malware employs Garble, an open-source tool, for code obfuscation to hide function names, structures, and logic. Brickstorm has been found on VMware vCenter and ESXi hosts, often deployed prior to pivoting to these systems. The attackers use legitimate cloud services like Cloudflare Workers or Heroku for C2 communications. The attackers use dynamic domains like sslip.io or nip.io that point directly to the C2 server’s IP. The attackers favor appliance and management-plane compromise, per-victim obfuscated Go binaries, delayed-start implants, and Web/DoH C2 to preserve stealth. The attackers harvest and use valid high-privilege credentials to appear as routine administrator tasks. The attackers deploy in-memory servlet filters, remove installer artifacts, and embed delayed-start logic to limit forensic traces. The attackers abuse virtualization management capabilities, such as cloning VMs to extract credential stores offline. The attackers deploy an in-memory Java Servlet filter on vCenter to intercept and decode web authentication to harvest high-privilege credentials. The attackers use a SOCKS proxy on compromised appliances to tunnel into internal networks for interactive access and file retrieval.

A zero-day vulnerability in WhatsApp (CVE-2025-55177) was exploited in targeted attacks against specific users, chained with a separate iOS flaw (CVE-2025-43300). The flaw allowed unauthorized users to trigger content processing from arbitrary URLs on targeted devices. Apple issued threat notifications to users targeted in mercenary spyware attacks, which included individuals based on their status or function, such as journalists, lawyers, activists, politicians, and senior officials. The attacks highlight the risks of chaining multiple vulnerabilities to compromise targets, emphasizing the need for comprehensive security measures. WhatsApp patched the issue and notified affected users. Apple has sent threat notifications multiple times a year since 2021, alerting users in over 150 countries, including a fourth campaign in France in 2025. The attacks began with the exploitation of the WhatsApp zero-day vulnerability, which was chained with an iOS flaw in sophisticated attacks. Apple has been issuing threat notifications to users targeted in these attacks, advising them to enable Lockdown Mode and seek emergency security assistance. Apple introduced Memory Integrity Enforcement (MIE) in the latest iPhone models to combat memory corruption vulnerabilities, and the number of U.S. investors in spyware and surveillance technologies has increased significantly.

Chinese state-sponsored Advanced Persistent Threat (APT) actors, specifically the Salt Typhoon group and a newly identified group named RedNovember, have been conducting sustained campaigns to compromise critical infrastructure networks worldwide. The campaigns aim to gain long-term access to telecommunications, government, transportation, lodging, and military networks. This activity has been detailed in a joint advisory by CISA, NSA, FBI, and international partners, including Canada, Australia, New Zealand, the UK, Czech Republic, Finland, Germany, Italy, Japan, the Netherlands, Poland, and Spain. The advisory provides intelligence on tactics used by these actors and recommends mitigations to strengthen defenses. The Czech Republic's National Cyber and Information Security Agency (NUKIB) has issued a warning instructing critical infrastructure organizations to avoid using Chinese technology or transferring user data to servers located in China. The agency has re-evaluated its risk estimate of significant disruptions caused by China, now assessing it at a 'High' level. The NUKIB has confirmed malicious activities of Chinese cyber-actors targeting the Czech Republic, including a recent APT31 campaign targeting the Czech Ministry of Foreign Affairs. The advisory highlights concerns over the transfer of system and user data to China, potentially misused by state, military, or political interests. The Czech government previously accused China of targeting its critical infrastructure through APT 31, an allegation denied by the PRC but condemned by the US, EU, and NATO. The advisory suggests that individuals and organizations consider restricting or prohibiting the use of products and services that transfer data to China. The campaign has targeted at least 600 organizations across 80 countries, including 200 in the U.S. The threat actors have exploited vulnerabilities in Cisco, Ivanti, and Palo Alto Networks devices to gain initial access and have modified routers to maintain persistent access and pivot into other networks. The advisory also notes that the APT actors may target other devices such as Fortinet firewalls, Juniper firewalls, Microsoft Exchange, Nokia routers and switches, Sierra Wireless devices, Sonicwall firewalls, etc. RedNovember has targeted perimeter appliances of high-profile organizations globally, including defense and aerospace organizations, space organizations, and law firms. The group has breached at least two U.S. defense contractors, a European engine manufacturer, and a trade-focused intergovernmental cooperation body in Southeast Asia. RedNovember has used the Go-based backdoor Pantegana and Cobalt Strike as part of its intrusions, along with the Spark RAT and LESLIELOADER. The group has also used VPN services like ExpressVPN and Warp VPN to administer and connect to servers used for exploitation and communication.

The Picus Blue Report 2025, based on over 160 million attack simulations, reveals that organizations detect only 1 out of 7 simulated attacks. This indicates significant gaps in threat detection and response capabilities, primarily due to log collection failures, misconfigured detection rules, and performance issues. These failures leave networks vulnerable to compromise, escalation of privileges, and data exfiltration. The report identifies key issues such as log source coalescing, unavailable log sources, and inefficient filtering as major contributors to SIEM rule failures. Continuous validation of SIEM rules is essential to maintain effectiveness against evolving threats. The report also shows that prevention dropped from 69% to 62% in one year, and that 54% of attacker behaviors generated no logs, making entire attack chains unfold with zero visibility. Only 14% of attacker behaviors triggered alerts, and data exfiltration was stopped just 3% of the time, leaving a critical stage effectively unprotected. The report highlights the need for Breach and Attack Simulation (BAS) to validate security defenses continuously.

In late 2024, the threat group Storm-0501 compromised hybrid cloud environments across multiple sectors, including government, manufacturing, transportation, law enforcement, schools, and healthcare. The group has been active since 2021, utilizing various ransomware-as-a-service (RaaS) strains. Storm-0501 exploited compromised credentials and overprivileged accounts to move laterally between cloud and on-premise environments, aiming to generate revenue through a ransomware affiliate scheme. This campaign highlights the challenges in maintaining consistent security postures across multicloud and hybrid-cloud environments. The attack underscores the need for unified security platforms and consistent policies to disrupt attack chains. Organizations struggle with managing multiple cloud environments due to inconsistent identity and access controls, tool sprawl, and the complexity of multicloud security architectures. The campaign also reveals the importance of gaining visibility into cloud events and establishing a strong security culture to manage multicloud environments effectively. Storm-0501's tactics include cloud-based ransomware attacks that exploit native capabilities of victim environments, compromising devices not connected to Microsoft Defender and gaining domain administrator privileges. The group used Azure tools to map relationships and permissions, targeting a second tenant by leveraging a non-human identity assigned to a Global Administrator role with no MFA. Storm-0501 has refined its tactics to conduct data exfiltration and extortion attacks, leveraging cloud-native capabilities to exfiltrate large volumes of data, destroy data and backups, and demand ransom without relying on traditional malware deployment.