Researcher Chaotic Eclipse Discloses HardBreacher Exploit Targeting Kaspersky Endpoint Security

Security researcher known by the moniker Chaotic Eclipse, who also operates under names such as INFINITE NIGHTMARE, MSNightmare and Nightmare-Eclipse, has published a proof‑of‑concept exploit named HardBreacher. The tool targets a privilege‑escalation vulnerability in Kaspersky Endpoint Security, effectively adding a new zero‑day to the author’s growing catalog of public disclosures.

HardBreacher leverages an unchecked privilege escalation flaw that allows an attacker with limited system access to obtain higher‑level rights within the Kaspersky software stack. By escalating privileges, malicious actors could potentially disable security controls, exfiltrate data, or deploy additional payloads, undermining the protection that enterprises rely on from the Russian‑based security suite.

The disclosure, first reported by Security Affairs, arrives amid heightened scrutiny of supply‑chain and endpoint security solutions. Kaspersky Endpoint Security is widely deployed across corporate environments for malware detection, application control, and device management. A vulnerability that compromises its core functions poses a particular risk because the software often runs with elevated system permissions to perform its protective duties.

While the exploit is currently limited to a proof‑of‑concept stage, its public availability raises concerns about potential weaponization. Security analysts note that the timeline between a zero‑day’s public release and its adoption by malicious actors can be short, especially when the affected software is prevalent. Organizations using Kaspersky products are advised to monitor vendor advisories, apply any forthcoming patches promptly, and consider temporary mitigations such as restricting user privileges or employing application whitelisting where feasible.

Chaotic Eclipse’s track record includes several previously disclosed vulnerabilities, and the researcher’s choice to release HardBreacher underscores the ongoing debate over responsible disclosure versus full public release. The cybersecurity community will be watching closely for Kaspersky’s response, which is expected to involve a security bulletin and a patch rollout. In the interim, security teams are encouraged to review their endpoint protection configurations and stay alert for any indicators of compromise that might be linked to the newly disclosed exploit.