Chaotic Eclipse Releases Kaspersky Zero-Day HardBreacher

Executive Summary

A proof‑of‑concept exploit named HardBreacher, targeting a privilege‑escalation flaw in Kaspersky Endpoint Security, was publicly released by the researcher known as Chaotic Eclipse. Enterprises that have Kaspersky Endpoint Security deployed are now exposed to a zero‑day that can grant attackers SYSTEM privileges on protected endpoints. Leadership must decide within the next 24 hours whether to accelerate patch procurement, isolate affected assets, and activate an incident‑response plan.

Verified Facts

• Chaotic Eclipse released a PoC exploit called HardBreacher that targets Kaspersky Endpoint Security – Security Affairs.
• The exploit triggers a privilege‑escalation flaw in Kaspersky Endpoint Security – Security Affairs.
• HardBreacher adds another zero‑day to the researcher’s publicly disclosed list – Security Affairs.

Threat Classification

Privilege‑escalation zero‑day exploit (T1068) affecting any organization that runs Kaspersky Endpoint Security worldwide; the exploit is publicly available as a PoC (active) and the researcher’s motivation is not disclosed (MEDIUM CONFIDENCE).

Threat Severity Assessment

• Exploitability – PoC is publicly released, enabling low‑skill actors to use it (HIGH CONFIDENCE).
• Impact – Successful execution yields SYSTEM‑level privileges, allowing full control of the endpoint (HIGH CONFIDENCE).
• Prevalence – Kaspersky Endpoint Security is deployed in many enterprises across multiple sectors (MEDIUM CONFIDENCE).
• Patch status – No vendor patch has been announced at the time of reporting (HIGH CONFIDENCE).

Overall Severity: HIGH

Business Impact

Successful exploitation can disable endpoint protection, exfiltrate sensitive data, and facilitate lateral movement, leading to operational downtime of critical services. A breach of personal data under GDPR could trigger fines up to €20 million or 4 % of annual turnover; under NIS2 or DORA, regulators may impose additional penalties for inadequate vulnerability management. Financial exposure is classified as high due to potential remediation costs, legal liabilities, and loss of productivity. Reputational damage may arise from public disclosure of a compromised security product, eroding customer trust in the organization’s security posture.

Technical Analysis

• Attack Vector – Execution of a malicious binary (HardBreacher) that exploits a privilege‑escalation flaw in Kaspersky Endpoint Security.
• Exploitation Chain – Attacker obtains user‑level code execution (e.g., via phishing) and runs HardBreacher to elevate to SYSTEM.
• Affected Component – Privileged service within Kaspersky Endpoint Security responsible for policy enforcement.
• Vulnerability Class – Privilege‑escalation flaw (no CVE identifier disclosed).
• Root Cause – Insufficient validation of privileged operations within the Kaspersky service, allowing arbitrary code execution with SYSTEM rights.

MITRE ATT&CK Mapping

• Privilege Escalation → T1068: Exploitation for Privilege Escalation — HardBreacher exploits a flaw in Kaspersky Endpoint Security to gain SYSTEM privileges.

IOC Intelligence

No public IOCs confirmed at time of publication.

Behavioral IOC categories for rule creation:

• Execution of a binary named HardBreacher.exe or similarly named unknown executable.
• Creation of a new Windows service whose binary resides in a non‑standard path (e.g., %TEMP%, %APPDATA%).
• Process tree showing a child process launched by a Kaspersky Endpoint Security service that inherits a SYSTEM token.
• Registry modifications under HKLM\SYSTEM\CurrentControlSet\Services adding a new service entry.

Detection Engineering Guidance

• Collect Sysmon Event ID 1 (Process Creation) and filter for HardBreacher.exe or unknown executables launched from temporary directories.
• Monitor Windows Event ID 7045 (Service Installation) for new services whose ImagePath points to non‑system locations.
• Correlate Windows Security Event ID 4688 (Process Creation) where the Creator Process is a Kaspersky Endpoint Security service and the New Process runs with a SYSTEM token.
• Ingest Kaspersky Endpoint Security logs for any “privilege escalation” or “elevated process” alerts and flag them for immediate review.
• Generate alerts when registry keys under HKLM\SYSTEM\CurrentControlSet\Services are added or modified by a non‑SYSTEM account.

Sigma Rules

title: New Service Installation with Suspicious Binary Path
id: 9f8c2a1e-3b4d-4f6a-9c2e-1d5b7a9c0f12
status: stable
description: Detects creation of a Windows service where the executable resides in a user‑writable directory, indicative of HardBreacher deployment.
logsource:
    product: windows
    service: system
detection:
    selection:
        EventID: 7045
        ImagePath|contains:
            - '\\Temp\\'
            - '\\AppData\\'
    condition: selection
falsepositives:
    - Legitimate software that installs services from user directories
level: high
tags:
    - attack.t1068
---
title: Execution of HardBreacher Binary
id: d3a7b9c4-5e6f-4a2b-8d1e-9f0c3b7e2a45
status: stable
description: Detects execution of the HardBreacher executable, a known privilege‑escalation PoC.
logsource:
    product: windows
    service: sysmon
detection:
    selection:
        EventID: 1
        Image|endswith: '\\HardBreacher.exe'
    condition: selection
falsepositives:
    - Research or testing environments where the PoC is intentionally run
level: critical
tags:
    - attack.t1068

Threat Hunting Queries

• Hypothesis: New services installed from user‑writable paths – Source: Windows Event Log (EventID=7045) – Query fields: ImagePath, ServiceName.
• Hypothesis: Kaspersky service spawning a child process with SYSTEM token – Source: Sysmon (EventID=1) – Query fields: ParentImage, Image, TokenElevationType.
• Hyp

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