Chinese Hacking Groups Exploiting Ivanti Connect Secure VPN


Cybersecurity firm Mandiant has uncovered a series of sophisticated cyberattacks targeting Ivanti Connect Secure VPN appliances.

These attacks, attributed to multiple Chinese nexus espionage groups, exploit critical vulnerabilities to facilitate lateral movement and compromise Active Directory systems.

This article delves into the intricate details of the CVEs involved, the clustering and attribution of these attacks, the deployment of new TTPs and malware, and the implications of such breaches.

CVEs: The Gateway to Exploitation

The initial disclosure of CVE-2023-46805 and CVE-2024-21887 on January 10, 2024, marked the beginning of a series of incident response engagements by Mandiant.

Document

Run Free ThreatScan on Your Mailbox

Trustifi’s Advanced threat protection prevents the widest spectrum of sophisticated attacks before they reach a user’s mailbox. Try Trustifi Free Threat Scan with Sophisticated AI-Powered Email Protection .


These vulnerabilities, an authentication bypass and a command injection flaw, have been the focal points of exploitation attempts by suspected Chinese nexus espionage actors.

The exploitation of these vulnerabilities underscores the critical need for timely patching and the application of appropriate mitigations.

As per the latest report by Google, several Chinese hacking groups are currently leveraging the vulnerability in Ivanti Connect Secure VPN to carry out their malicious activities.

Clustering and Attribution

Mendiant’s investigations have led to the clustering of these cyberattacks under the activities of two primary groups: UNC5325 and UNC5337.

Both groups are suspected of having ties to China and of using the aforementioned CVEs to compromise Ivanti Connect Secure VPN appliances.

The attribution to these groups is based on deploying custom malware families and evolving their tactics, techniques, and procedures (TTPs) to exploit appliance-specific functionalities.

New TTPs and Malware

The evolution of attacker methodologies has been evident in deploying new TTPs and malware.

UNC5337, in particular, has been observed leveraging multiple custom malware families, including the SPAWNSNAIL passive backdoor, SPAWNMOLE tunneler, SPAWNANT installer, and SPAWNSLOTH log tampering utility.

These tools facilitate the persistence and lateral movement within compromised networks, showcasing the sophistication of these threat actors.

SPAWN Malware Family

The SPAWN malware family represents a significant advancement in the arsenal of these espionage groups.

PAWN malware family diagram
PAWN malware family diagram

Each family component serves a unique purpose, from establishing backdoor access to facilitating network tunneling and tampering with logs to evade detection.

The deployment of these tools highlights the attackers’ strategic planning and technical prowess.

While the focus has been on exploiting Ivanti Connect Secure VPN appliances, Mandiant has also identified a campaign dubbed BRICKSTORM.

This campaign leverages similar tactics and malware to target other critical infrastructures, indicating a broader threat landscape and the adaptability of these espionage groups.

Lateral Movement Leading to Active Directory Compromise

One of the most concerning aspects of these attacks is the threat actors’ ability to leverage lateral movement techniques to compromise Active Directory systems.

UNC5330 attack path diagram
UNC5330 attack path diagram

This not only allows for the escalation of privileges but also facilitates the exfiltration of sensitive information and the deployment of additional payloads across the network.

Multiple Chinese nexus espionage groups exploit Ivanti Connect Secure VPN flaws, representing a significant threat to global cybersecurity.

The deployment of new TTPs and malware, coupled with the ability to compromise critical systems, underscores the need for vigilant cybersecurity practices and the timely application of patches and mitigations.

As these threat actors evolve their strategies, the cybersecurity community must remain proactive in its defense measures to protect against such sophisticated attacks.

Indicators of Compromise (IOCs)

Host-Based Indicators (HBIs)

libdsproxy. so MD5 Description
data.dat 9d684815bc96508b99e6302e253bc292 PHANTOMNET
epdevmgr.dll b210a9a9f3587894e5a0f225b3a6519f TONERJAM
libdsmeeting.so 4f79c70cce4207d0ad57a339a9c7f43c SPAWNMOLE
libdsmeeting.so e7d24813535f74187db31d4114f607a1 SPAWNSNAIL
.liblogblock.so 4acfc5df7f24c2354384f7449280d9e0  SPAWNSLOTH
.dskey 3ef30bc3a7e4f5251d8c6e1d3825612d SPAWNSNAIL private key
N/A bb3b286f88728060c80ea65993576ef8 TERRIBLETEA
N/A cfca610934b271c26437c4ce891bad00 TERRIBLETEA
N/A 08a817e0ae51a7b4a44bc6717143f9c2 TERRIBLETEA
linb64.png e7fdbed34f99c05bb5861910ca4cc994 SLIVER
lint64.png c251afe252744116219f885980f2caea SLIVER
linb64.png 4f68862d3170abd510acd5c500e43548 SLIVER
lint64.png 9d0b6276cbc4c8b63c269e1ddc145008 SLIVER
logd 71b4368ef2d91d49820c5b91f33179cb SLIVER
winb64.png d88bbed726d79124535e8f4d7de5592e SLIVER
logd.spec.cfg 846369b3a3d4536008a6e1b92ed09549 SLIVER persistence
N/A 8e429d919e7585de33ea9d7bb29bc86b SLIVER downloader
N/A fc1a8f73010f401d6e95a42889f99028 PHANTOMNET
N/A e72efc0753e6386fbca0a500836a566e PHANTOMNET
N/A 4645f2f6800bc654d5fa812237896b00 BRICKSTORM
Table 4: Host-based indicators

Network-Based Indicators (NBIs)

Network Indicator Type Description
8.218.240[.]85 IPv4 Post-exploitation activity
98.142.138[.]21 IPv4 Post-exploitation activity
103.13.28[.]40 IPv4 Post-exploitation activity
103.27.110[.]83 IPv4 Post-exploitation activity
103.73.66[.]37 IPv4 Post-exploitation activity
193.149.129[.]191 IPv4 Post-exploitation activity
206.188.196[.]199 IPv4 Post-exploitation activity
oast[.]fun Domain Pre-exploitation validation
cpanel.netbar[.]org Domain WARPWIRE Variant C2 server
pan.xj[.]hk Domain Post-exploitation activity
akapush.us[.]to Domain SLIVER C2 server
opra1.oprawh.workers.dev Domain BRICKSTORM C2 server
Table 5: Network-based indicators

Stay updated on Cybersecurity news, Whitepapers, and Infographics. Follow us on LinkedIn & Twitter.





Source link