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Chinese Spies Hack Dutch Networks With Novel Coathanger Malware

criticalMalwareimportance 60CVE-2022-42475

Vulnerabilities mentionedAll →

CVEVulnerabilityCVSSEPSSFlagsAffectedExposurePublished
CVE-2022-42475
Unauthenticated Heap Overflow in Fortinet FortiOS/FortiProxy SSL-VPN (Critical RCE)

CVE-2022-42475 is a critical (CVSS 9.8) heap-based buffer overflow in the SSL-VPN service of Fortinet FortiOS and FortiProxy. A remote, unauthenticated attacker can trigger it by sending specifically crafted requests to an exposed SSL-VPN interface, with no user interaction or credentials required. Successful exploitation yields arbitrary code or command execution on the appliance, giving attackers a foothold on the perimeter device from which they can pivot into internal networks. Any organization running the listed FortiOS (6.0 through 7.2) or FortiProxy (7.0/7.2) versions with SSL-VPN enabled is affected. Exploitation is confirmed in the wild: the flaw is in CISA KEV with known ransomware use, has near-certain exploitation probability (EPSS 99.5%), and has been used in targeted government attacks and a Chinese-nexus espionage campaign that compromised over 20,000 systems, with attackers also noted to retain access even after patching.

Do: Upgrade FortiOS and FortiProxy to fixed releases per Fortinet advisory FG-IR-22-398 (any version beyond the listed affected ranges), and reboot the appliance after patching to clear lingering SSL-VPN sessions since attackers have been observed retaining access post-patch. Check for indicators of compromise such as unknown local accounts, unexpected processes, and anomalous historical logins, and rotate SSL-VPN credentials if compromise is suspected. If SSL-VPN is not required, disable it or restrict exposure to trusted sources until patched.

9.899% KEV ransomware PoC
  • Fortinet FortiOS SSL-VPN 7.2.0 through 7.2.2, 7.0.0 through 7.0.8, 6.4.0 through 6.4.10, 6.2.0 through 6.2.11, and 6.0.15 and earlier
  • Fortinet FortiProxy SSL-VPN 7.2.0 through 7.2.1, and 7.0.7 and earlier
masshundreds of thousands of internet-exposed FortiGate/FortiProxy SSL-VPN endpoints (well over 100,000; 20,000+ confirmed victims in a single campaign)
Full article458 words · extracted from infosecurity-magazine.com · click to collapse

Chinese state-backed spies infiltrated Dutch defense networks last year and used novel malware dubbed “Coathanger” in a bid to steal sensitive information, according to the intelligence and security services of the Netherlands.

The country’s Military Intelligence and Security Service (MIVD) and General Intelligence and Security Service (AIVD) revealed in a detailed report yesterday that the initial intrusion began with exploitation of CVE-2022-42475.

Fortinet published a critical advisory for the zero-day vulnerability in December 2022 and warned that it was being exploited by an “advanced actor” in attacks on “governmental or government-related targets.”  

Post-exploitation, the Chinese threat actors then used a new “stealthy and persistent” remote access Trojan (RAT), dubbed Coathanger.

“It hides itself by hooking system calls that could reveal its presence. It survives reboots and firmware upgrades,” the Dutch intelligence report explained.

“MIVD & AIVD assess that use of Coathanger may be relatively targeted. The Chinese threat actor(s) scan for vulnerable edge devices at scale and gain access opportunistically, and likely introduce Coathanger as a communication channel for select victims.”

The report noted that the RAT could be used in combination with any vulnerability exploited on FortiGate devices. However, this time, Dutch network defenders appear to have foiled the cyber-espionage plot.

“Post compromise, the actor conducted reconnaissance of the R&D network and exfiltrated a list of user accounts from the Active Directory server. The impact of the intrusion was limited because the victim network was segmented from the wider MOD networks,” the report revealed.

The report is the first time the Netherlands has publicly called out Beijing for state-sponsored hacking. However, the country’s tech giant ASML plays a critical role in the global supply chain for advanced chips, which has raised the profile of the small northern European nation among certain governments.

Threat Actors Hit the Edge

MIVD and AIVD claimed that the attack is illustrative of a broader trend for threat actors to target edge devices such as VPNs, email servers and firewalls, which are connected to the public internet but often not protected by endpoint detection and response (EDR) monitoring.

Recent zero-day attacks on Ivanti devices by Chinese nexus threat actors bear this point out.

The Dutch intelligence services advised organizations to mitigate edge device threats by:

  • Regularly performing a risk analysis on the devices, such as when new functionality is added
  • Limiting internet access by disabling unused ports and functionalities, and ensuring the management interface is not accessible from the internet
  • Regularly performing analysis of logs to detect anomalous activity, including login attempts at unusual times, unknown IP addresses or unauthorized configuration changes
  • Installing the latest vendor security updates as soon as they become available and switching on any security-related functionality made available by suppliers
  • Replacing hardware and software that is no longer supported

Text extracted automatically; images, tables and formatting may be missing. Original: https://www.infosecurity-magazine.com/news/chinese-spies-hack-dutch-1/