Geolocation-based cyberattacks and their evolving threat landscape

The Cybersecurity and Infrastructure Security Agency (CISA) issued Emergency Directive 25-03, mandating federal agencies to identify and mitigate zero-day vulnerabilities in Cisco Adaptive Security Appliances (ASA) exploited by an advanced threat actor. The directive requires agencies to account for all affected devices, collect forensic data, and upgrade or disconnect end-of-support devices by September 26, 2025. The vulnerabilities allow threat actors to maintain persistence and gain network access. Cisco identified multiple zero-day vulnerabilities (CVE-2025-20333, CVE-2025-20362, CVE-2025-20363, and CVE-2025-20352) in Cisco ASA, Firewall Threat Defense (FTD) software, and Cisco IOS software. These vulnerabilities enable unauthenticated remote code execution, unauthorized access, and denial of service (DoS) attacks. GreyNoise detected large-scale campaigns targeting ASA login portals and Cisco IOS Telnet/SSH services, indicating potential exploitation of these vulnerabilities. The campaign is widespread and involves exploiting zero-day vulnerabilities to gain unauthenticated remote code execution on ASAs, as well as manipulating read-only memory (ROM) to persist through reboot and system upgrade. CISA and Cisco linked these ongoing attacks to the ArcaneDoor campaign, which exploited two other ASA and FTD zero-days (CVE-2024-20353 and CVE-2024-20359) to breach government networks worldwide since November 2023. CISA ordered agencies to identify all Cisco ASA and Firepower appliances on their networks, disconnect all compromised devices from the network, and patch those that show no signs of malicious activity by 12 PM EDT on September 26. CISA also ordered that agencies must permanently disconnect ASA devices that are reaching the end of support by September 30 from their networks. The U.K. National Cyber Security Centre (NCSC) confirmed that threat actors exploited the recently disclosed security flaws in Cisco firewalls to deliver previously undocumented malware families like RayInitiator and LINE VIPER. Cisco began investigating attacks on multiple government agencies in May 2025, linked to the state-sponsored ArcaneDoor campaign. The attacks targeted Cisco ASA 5500-X Series devices to implant malware, execute commands, and potentially exfiltrate data. The threat actor modified ROMMON to facilitate persistence across reboots and software upgrades. The compromised devices include ASA 5500-X Series models running specific software releases with VPN web services enabled. The Canadian Centre for Cyber Security urged organizations to update to a fixed version of Cisco ASA and FTD products to counter the threat. Nearly 50,000 Cisco ASA and FTD appliances are vulnerable to actively exploited flaws. The vulnerabilities CVE-2025-20333 and CVE-2025-20362 enable arbitrary code execution and access to restricted URL endpoints. The Shadowserver Foundation discovered over 48,800 internet-exposed ASA and FTD instances still vulnerable to the flaws. The majority of vulnerable devices are located in the United States, followed by the United Kingdom, Japan, Germany, Russia, Canada, and Denmark. The Shadowserver Foundation's data is as of September 29, indicating a lack of response to the ongoing exploitation activity. Greynoise had warned on September 4 about suspicious scans targeting Cisco ASA devices, indicating upcoming undocumented flaws. CISA's emergency directive gave 24 hours to FCEB agencies to identify and upgrade vulnerable Cisco ASA and FTD instances. CISA advised that ASA devices reaching their end of support should be disconnected from federal networks by the end of September. The U.K. NCSC reported that the hackers deployed Line Viper shellcode loader malware and RayInitiator GRUB bootkit.

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 U.S. federal civilian executive branch (FCEB) agency was breached in July 2024 after attackers exploited an unpatched GeoServer instance. The attackers gained initial access through a critical remote code execution (RCE) vulnerability (CVE-2024-36401) and moved laterally within the network, deploying web shells and scripts for persistence and privilege escalation. The breach remained undetected for three weeks until the agency's Endpoint Detection and Response (EDR) tool alerted the Security Operations Center (SOC). The attackers exploited the vulnerability in GeoServer, which was patched in June 2024 but remained unpatched in the agency's environment. They used brute force techniques for lateral movement and privilege escalation, accessing service accounts and deploying web shells like China Chopper. The breach highlights the importance of timely patching, continuous monitoring of EDR alerts, and comprehensive incident response plans. The attackers discovered the vulnerable GeoServer instances by conducting network scanning with Burp Suite. They exploited the vulnerability to gain access to a public-facing GeoServer instance and downloaded open-source scripts and tools for lateral movement. On July 24, 2024, the attackers exploited the same vulnerability to gain access to a second GeoServer instance and moved laterally to a Web server and SQL server, where they dropped web shells, including China Chopper. The attackers also used Stowaway for command-and-control (C2) traffic and attempted to exploit CVE-2016-5195 for privilege escalation. The agency's incident response plan was inadequate, and some public-facing resources lacked endpoint protection, allowing the breach to remain undetected for three weeks.

A new attack vector, dubbed ShadowLeak, allows hackers to invisibly steal emails from users who integrate AI agents like ChatGPT with their email inboxes. The attack exploits the lack of visibility into AI processing on cloud infrastructure, making it undetectable to the user. The vulnerability was discovered by Radware and reported to OpenAI, which addressed it in August 2025. The attack involves embedding malicious code in emails, which the AI agent processes and acts upon without user awareness. The attack leverages an indirect prompt injection hidden in email HTML, using techniques like tiny fonts, white-on-white text, and layout tricks to remain undetected by the user. The attack can be extended to any connector that ChatGPT supports, including Box, Dropbox, GitHub, Google Drive, HubSpot, Microsoft Outlook, Notion, or SharePoint. The ShadowLeak attack targets users who connect AI agents to their email inboxes, such as those using ChatGPT with Gmail. The attack is non-detectable and leaves no trace on the user's network. The exploit involves embedding malicious code in emails, which the AI agent processes and acts upon, exfiltrating sensitive data to an attacker-controlled server. OpenAI acknowledged and fixed the issue in August 2025, but the exact details of the fix remain unclear. The exfiltration in ShadowLeak occurs directly within OpenAI's cloud environment, bypassing traditional security controls.

Two malware strains were discovered in an organization's network after attackers exploited two zero-day vulnerabilities in Ivanti Endpoint Manager Mobile (EPMM). The vulnerabilities, CVE-2025-4427 and CVE-2025-4428, allow for authentication bypass and remote code execution, respectively. Attackers used these flaws to gain access to the EPMM server, execute arbitrary code, and maintain persistence. The attack began around May 15, 2025, following the publication of a proof-of-concept exploit. The malware sets include loaders that enable arbitrary code execution and data exfiltration. The vulnerabilities affect Ivanti EPMM development branches 11.12.0.4, 12.3.0.1, 12.4.0.1, and 12.5.0.0 and their earlier releases. A China-nexus espionage group was leveraging the vulnerabilities since at least May 15, 2025. The threat actor targeted the /mifs/rs/api/v2/ endpoint with HTTP GET requests and used the ?format= parameter to send malicious remote commands. The malware sets include distinct loaders with the same name, and malicious listeners that allow injecting and running arbitrary code on the compromised system. The threat actor delivered the malware through separate HTTP GET requests in segmented, Base64-encoded chunks. Organizations are advised to update their EPMM instances, monitor for suspicious activity, and implement access restrictions to prevent unauthorized access to mobile device management systems.