{
  "family": "killapp",
  "sample_count": 1,
  "category": "ransomware",
  "description": "<h3>Executive Summary</h3>\nKillApp (often detected as Riskware.KillApp, Tool.KillApp, or Trojan.KillApp) identifies a specific class of malicious utilities or scripts designed with a singular purpose: to forcefully terminate running processes, specifically targeting antivirus (AV), Endpoint Detection and Response (EDR) agents, and other critical security software. Threat actors use KillApp in the very early stages of an attack to blind the system before deploying their primary payload.\n\n<h3>Technical Architecture and Exploitation</h3>\nKillApp is typically not a standalone threat; it is usually dropped and executed by an initial loader or macro immediately prior to the execution of a more destructive payload (like ransomware).\n\nIts execution lifecycle relies heavily on aggressive system manipulation:\n<ul>\n<li><strong>Process Enumeration:</strong> Upon execution, KillApp rapidly enumerates all running processes on the system, cross-referencing them against a hardcoded list of known security vendors (e.g., `MsMpEng.exe`, `ekrn.exe`, `avp.exe`).</li>\n<li><strong>Forceful Termination:</strong> It utilizes Windows APIs (such as `TerminateProcess`) to forcefully kill the identified security software. </li>\n<li><strong>Service Disablement:</strong> To ensure the AV does not restart, advanced variants of KillApp will attempt to stop the associated Windows Services and alter their startup type in the Registry (e.g., `HKLM\\SYSTEM\\CurrentControlSet\\Services`) to \"Disabled.\"</li>\n</ul>\n\n<h3>Threat Impact</h3>\nA KillApp detection is a critical, \"break-glass\" security incident. The presence of this tool indicates that a threat actor has successfully gained execution on a host and is actively attempting to strip away its defenses. If KillApp succeeds, the system is completely vulnerable to whatever secondary payload the attacker chooses to deploy next.\n\n<h3>Incident Response and Mitigation</h3>\n<ul>\n<li><strong>EDR Tamper Protection:</strong> The most effective defense against KillApp is robust Tamper Protection within the EDR/AV solution. This prevents unauthorized processes (even those running as Administrator) from terminating the EDR agent or modifying its core files and registry keys.</li>\n<li><strong>Immediate Network Isolation:</strong> If an alert fires indicating that security services have been stopped or terminated unexpectedly, the endpoint must be isolated from the network immediately, as a secondary payload is likely imminent.</li>\n<li><strong>Forensic Investigation:</strong> Because KillApp is a precursor tool, incident responders must immediately investigate *how* KillApp was executed (e.g., tracing it back to a weaponized document or a compromised remote access tool).</li>\n</ul>",
  "cta": "Published by the SystemHelpdesk team.",
  "aliases": [
    "Riskware.KillApp",
    "Tool.KillApp",
    "Trojan:Win32/KillApp"
  ],
  "enrichment_level": "insufficient_information",
  "faq": [],
  "faq_count": 0,
  "mitre_attack": [
    "T1562.001",
    "T1489",
    "T1059"
  ],
  "cisa_advisory": null,
  "last_updated": "2026-07-01T16:40:53Z",
  "type": "Riskware / HackTool",
  "target_industries": [
    "Global / Opportunistic"
  ],
  "motivation": "Opportunistic",
  "threat_actors": [
    "Unknown / Cybercriminal"
  ],
  "target_geographies": [
    "Global"
  ]
}