# NightmareEclipse

> As of 2026-09-22, NightmareEclipse is a threat actor tracked by Threadlinqs Intelligence across 4 threats spanning vulnerability. ATT&CK coverage spans 54 techniques across 14 tactics in 4 of 4 tracked threats. Most-observed techniques: T1033 (System Owner/User Discovery), T1068 (Exploitation for Privilege Escalation), T1005 (Data from Local System).

- **Tracked threats:** 4
- **Categories:** VULNERABILITY
- **As of:** 2026-09-22

## ATT&CK techniques observed

54 techniques observed across 4 of 4 tracked threats. Tactics: Stealth (formerly Defense Evasion) (9), Persistence (7), Discovery (6), Credential Access (5), Execution (5), Privilege Escalation (5).

- [T1033](https://intel.threadlinqs.com/technique/T1033) System Owner/User Discovery — Discovery — observed in 3 of 4 tracked threats
- [T1068](https://intel.threadlinqs.com/technique/T1068) Exploitation for Privilege Escalation — Privilege Escalation — observed in 3 of 4 tracked threats
- [T1005](https://intel.threadlinqs.com/technique/T1005) Data from Local System — Collection — observed in 2 of 4 tracked threats
- [T1069](https://intel.threadlinqs.com/technique/T1069) Permission Groups Discovery — Discovery — observed in 2 of 4 tracked threats
- [T1074.001](https://intel.threadlinqs.com/technique/T1074.001) Local Data Staging — Collection — observed in 2 of 4 tracked threats
- [T1078.003](https://intel.threadlinqs.com/technique/T1078.003) Local Accounts — Initial Access — observed in 2 of 4 tracked threats
- [T1082](https://intel.threadlinqs.com/technique/T1082) System Information Discovery — Discovery — observed in 2 of 4 tracked threats
- [T1106](https://intel.threadlinqs.com/technique/T1106) Native API — Execution — observed in 2 of 4 tracked threats
- [T1112](https://intel.threadlinqs.com/technique/T1112) Modify Registry — Defense Impairment — observed in 2 of 4 tracked threats
- [T1134](https://intel.threadlinqs.com/technique/T1134) Access Token Manipulation — Privilege Escalation — observed in 2 of 4 tracked threats
- [T1546](https://intel.threadlinqs.com/technique/T1546) Event Triggered Execution — Persistence — observed in 2 of 4 tracked threats
- [T1550](https://intel.threadlinqs.com/technique/T1550) Use Alternate Authentication Material — Lateral Movement — observed in 2 of 4 tracked threats
- [T1564](https://intel.threadlinqs.com/technique/T1564) Hide Artifacts — Stealth (formerly Defense Evasion) — observed in 2 of 4 tracked threats
- [T1649](https://intel.threadlinqs.com/technique/T1649) Steal or Forge Authentication Certificates — Credential Access — observed in 2 of 4 tracked threats
- [T1685](https://intel.threadlinqs.com/technique/T1685) Disable or Modify Tools — Defense Impairment — observed in 2 of 4 tracked threats

## Tracked threats

- [BigDiskBuster PoC Blocks Microsoft Defender Antivirus Updates via Disk-Space Exhaustion](https://intel.threadlinqs.com/threat/TL-2026-2618) — MEDIUM
- [NightmareEclipse Coordinated Disclosure Breach Campaign: 9+ Windows Zero-Days (CVE-2026-33825, CVE-2026-41091, CVE-2026-45498, CVE-2026-45585, CVE-2026-45586) Dumped Outside Responsible Disclosure and Weaponized in Real-World Intrusions](https://intel.threadlinqs.com/threat/TL-2026-1865) — CRITICAL
- [LegacyHive: Windows 0-Day Local Privilege Escalation via User Profile Service (ProfSvc) Arbitrary Registry Hive Loading](https://intel.threadlinqs.com/threat/TL-2026-1449) — HIGH
- [LegacyHive: Unpatched Windows User Profile Service (ProfSvc) Local Privilege Escalation Zero-Day — Public PoC Bypasses Fully Patched Systems](https://intel.threadlinqs.com/threat/TL-2026-1445) — HIGH

## Related CVEs

5 CVEs referenced by tracked NightmareEclipse activity.

- [CVE-2026-45586](https://intel.threadlinqs.com/cve/CVE-2026-45586)
- [CVE-2026-45585](https://intel.threadlinqs.com/cve/CVE-2026-45585)
- [CVE-2026-45498](https://intel.threadlinqs.com/cve/CVE-2026-45498)
- [CVE-2026-41091](https://intel.threadlinqs.com/cve/CVE-2026-41091)
- [CVE-2026-33825](https://intel.threadlinqs.com/cve/CVE-2026-33825)

## Full data

Infrastructure, IOC values and detection queries (Splunk SPL / Microsoft KQL / Sigma) require the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp

Canonical: https://intel.threadlinqs.com/actor/NightmareEclipse