New Mirai Botnet Variant Targets Comtrend Router Vulnerability (CVE-2020-10173)

A newly identified Mirai botnet variant (IoT.Linux.MIRAI.VWISI) has begun exploiting CVE-2020-10173, a command injection vulnerability in Comtrend VR-3033 routers. This development represents the first observed use of this specific vulnerability by Mirai malware, demonstrating the botnet’s continued evolution and expanding attack surface against IoT devices.

Executive Summary

Security teams should note this variant combines traditional Mirai brute-force tactics with vulnerability exploitation. While current distribution appears limited, the malware’s capability to compromise network infrastructure through router vulnerabilities elevates its potential impact. The threat maintains Mirai’s characteristic DDoS capabilities while incorporating new infection vectors that bypass conventional credential-based defenses.

Technical Analysis

The malware exploits CVE-2020-10173 through crafted HTTP POST requests to the router’s configuration interface. Successful exploitation allows execution of arbitrary commands with root privileges. Analysis reveals the variant uses XOR encryption (key: 0x04) to obfuscate configuration strings and command-and-control communications.

Infection occurs through two primary vectors: exploitation of vulnerable Comtrend routers and traditional telnet/SSH brute-forcing against other IoT devices. The malware tests 64 common credential pairs including predictable defaults like admin:admin and support:support.

Detection and Mitigation

Organizations should prioritize patching Comtrend VR-3033 routers and similar devices. Network monitoring for connections to known C2 domains (methcnc[.]duckdns[.]org, methscan[.]duckdns[.]org) can help identify compromised systems. The malware’s SHA256 hash (66545fffeed4f413827f9dc51d2444aaa772adf4d44f65662356b1301e45390d) should be added to detection systems.

Recommended defensive measures include network segmentation for IoT devices, credential hardening, and implementation of egress filtering to block connections to dynamic DNS providers commonly abused by botnets.

Strategic Implications

This variant demonstrates Mirai operators’ continued investment in expanding their vulnerability arsenal. The combination of vulnerability exploitation and credential brute-forcing creates multiple infection pathways, increasing the botnet’s resilience against defensive measures.

Security teams should anticipate future variants incorporating additional router and IoT device vulnerabilities. Proactive identification and remediation of vulnerable network infrastructure becomes increasingly critical as botnets evolve beyond simple credential-based attacks.