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Chinese APT Exploits CA Misconfiguration and File Upload Vulnerability in UAE Government Entity

By Help AG

Help AG DFIR and CTI team has observed a targeted cyber intrusion campaign attributed to a Chinese state-aligned APT group, affecting a UAE government entity. The threat actor initially gained access by compromising a service account configured with scheduled task execution privileges.

Upon entry, the actor escalated privileges from a regular domain user to a domain administrator by exploiting a misconfigured Certificate Authority (CA). By manipulating the Subject Alternative Name (SAN) field during certificate enrolment, they obtained a valid certificate for a privileged domain admin account and subsequently conducted a DCSync attack, extracting Active Directory password hashes.

The threat actor also exploited a file upload vulnerability to deploy eight web shells across web servers, using them for post-exploitation command execution and establishing network tunnels for sustained access.

TTPs:

T1053.005 – Scheduled Task/Job: Scheduled Task – Service account abuse
T1078 – Valid Accounts: Use of compromised service account
T1550.003 – Use Alternate Authentication Material: Web Session Cookie – Certificate abuse
T1552.001 – Unsecured Credentials: Credentials In Files – Scheduled task credential exposure
T1556.002 – Modify Authentication Process: Password Filter DLL – CA misconfiguration leveraged
T1003.006 – OS Credential Dumping: DCSync – Extracted AD hashes
T1505.003 – Server Software Component: Web Shell – Persistent access via upload
T1071.001 – Application Layer Protocol: Web Protocols – C2 via web shells
T1572 – Protocol Tunneling: Attacker-controlled tunnels
T1059.001 – Command and Scripting Interpreter: PowerShell – Post-exploitation
T1021.002 – Remote Services: SMB/Windows Admin Shares – Lateral movement

YARA Rules:

rule Suspicious_Base64

rule Suspicious_Base64
{
    meta:
        description = "Post Exploitation Tool"
        author = "Help AG CTI"

    strings:
        $b64_marker = /[A-Za-z0-9+\/]{100,}={0,1000}.{0,5}ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmn/
        $bss = ".bss"

    condition:
        $bss in (0..filesize) and $b64_marker
}

rule Golang_based_FRP

rule Golang_based_FRP
{
    meta:
        description = "Go Lang Based FRP"
        author = "Help AG CTI"

    strings:
        $s1 = "server_addr" wide ascii
        $s2 = "server_port" wide ascii
        $s4 = "remote_port" wide ascii
        $s5 = "plugin_passwd" wide ascii
        $s6 = "plugin_user" wide ascii

    condition:
        3 of ($s*)
}

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Delivered in ready-to-use formats for seamless SIEM and SOC integration, our IOC packs provide the visibility needed to detect, contain, and prevent advanced attacks. With continuous updates, contextual enrichment, and expert support from our analysts, subscribers can transform raw indicators into meaningful protection and resilience for their critical assets.

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Recommendations

Review and restrict certificate template permissions, especially SAN field enrolment.
Audit and disable unnecessary scheduled tasks tied to service accounts.
Patch file upload vulnerabilities across all web applications.
Continuously monitor for abnormal certificate requests from domain-joined machines.
Harden Active Directory against DCSync abuse by limiting replication permissions.
Deploy WAF rules to detect and block known web shell patterns.
Isolate web-facing servers with strong segmentation from internal systems.
Enable command-line and PowerShell logging for suspicious post-exploitation activities.

Protect Your Organization Against Advanced Threats

Incidents like this demonstrate the sophisticated tactics employed by state-aligned APT groups. Staying ahead requires proactive intelligence, rapid detection, and expert response capabilities.

Our Digital Forensics & Incident Response (DFIR) capabilities, we help organizations quickly contain breaches, investigate intrusions, and strengthen their security posture against future threats.

Contact Help AG today to access tailored threat intelligence, IOC packages, and expert support to fortify your organization against sophisticated cyber adversaries.