HOPLIGHT: North Korean Trojan malware analysis
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CISA and FBI identified HOPLIGHT, a North Korean Trojan that exfiltrates system data via SSL-encrypted proxy connections.
CISA and FBI jointly identified nine malware variants used by North Korea's government, collectively called HOPLIGHT and attributed to the HIDDEN COBRA campaign. The malware acts as a Trojan capable of collecting system information, enumerating drives and partitions, reading and writing files, creating and terminating processes, injecting into running processes, managing services, modifying registry settings, and uploading/downloading files. The variants use public SSL certificates (spoofed Naver.com certs) to disguise command-and-control communications with remote operators over HTTPS. Seven variants act as proxy applications that relay traffic; one contains encoded payloads; one drops four configuration files containing hardcoded IP addresses and SSL certificates. The malware targets both 32-bit and 64-bit Windows systems. Some variants load credential-harvesting APIs associated with Pass-The-Hash toolkits, enabling lateral movement through stolen credentials. Analysis identified four hardcoded command servers used for outbound TLS connections on ports 443 and 7443. The malware uses a unique unicode string per infected system for identification. Defenders should flag and report any activity associated with these hashes and IP addresses to CISA or FBI with highest priority.
Mentioned in this report
Detection guidance
Non-Browser Process Making Outbound Connection to TCP 7443
Detects a non-browser process initiating an outbound connection to TCP 7443 on a public address, a non-standard TLS port used by HOPLIGHT for C2 alongside 443. Auto-generated starting point — validate and tune in your environment before deploying. IOC matches can false-positive on shared infrastructure and decay as adversary infrastructure rotates.
title: Non-Browser Process Making Outbound Connection to TCP 7443
description: Detects outbound connections to TCP port 7443 on public addresses from
processes that are not web browsers. HOPLIGHT proxy/trojan variants used TLS with
spoofed public certificates on ports 443 and 7443 to hide C2 traffic. Port-based
and context-dependent, so triage the initiating process, its path and its signer.
tags:
- attack.command-and-control
- attack.t1571
- attack.t1573
logsource:
category: network_connection
product: windows
detection:
selection:
Initiated: 'true'
DestinationPort: 7443
filter_browsers:
Image|endswith:
- \chrome.exe
- \msedge.exe
- \firefox.exe
- \iexplore.exe
filter_private:
DestinationIp|cidr:
- 10.0.0.0/8
- 172.16.0.0/12
- 192.168.0.0/16
- 127.0.0.0/8
- 169.254.0.0/16
condition: selection and not 1 of filter_*
falsepositives:
- Enterprise applications or management consoles that legitimately listen on 7443
(for example VMware, Oracle or Cisco management services)
- Security or backup agents that use 7443 for cloud connectivity
level: low
id: ba08b9a8-e4d9-5e1f-9e47-39e666335d77
status: experimental
author: Vorant
references:
- https://www.cisa.gov/news-events/analysis-reports/ar19-100a
4 more detections for this report are in the app — the rules that match its indicators, plus the Sigma rules already converted to Splunk SPL, to Elastic where their fields map onto Elastic's integrations and to Microsoft Defender XDR KQL wherever Defender records the activity, and the YARA and Suricata. Three days of it free, no card.
Behavioural rules are generated from public reporting — validate in your environment before deploying.
Source reporting: https://www.cisa.gov/news-events/analysis-reports/ar19-100a
What this brief leaves out
This page is the free tier: the write-up, the severity, the names. In the app the same report carries its extracted indicators, its detections (Splunk SPL already written, plus Elastic and Microsoft KQL where they apply), the actors and CVEs it names as live profiles, and the vendor research on the same campaign — the primary source the news paraphrased, cited and read directly.
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