{
  "family": "shellme",
  "sample_count": 1,
  "category": "ransomware",
  "description": "<h3>Executive Summary</h3>\nShellme is a classification applied to a category of HackTools specifically designed to establish reverse shells or bind shells. While frequently utilized by authorized penetration testers and Red Teams, the detection of Shellme on a production system is a critical indicator that an attacker has achieved arbitrary command execution and established an interactive backdoor for complete, remote control of the endpoint.\n\n<h3>Technical Capabilities and Abuse</h3>\nShellme utilities are usually not distributed via spam. They are post-exploitation tools, uploaded and executed by an attacker *after* they have successfully exploited a vulnerability (like an unpatched web application flaw or a weak service password) to gain initial access.\n\nOnce executed, the tool provides direct command-line access:\n<ul>\n<li><strong>Reverse Shell Execution:</strong> The most common implementation forces the compromised machine to initiate an outbound network connection back to an attacker-controlled listening post. This technique is highly effective at bypassing inbound firewall rules and Network Address Translation (NAT).</li>\n<li><strong>Interactive Command Interface:</strong> The attacker is presented with a standard OS shell (e.g., `cmd.exe` or `/bin/bash`). They can execute any command with the privileges of the user account under which the Shellme executable was launched.</li>\n<li><strong>Lateral Movement Gateway:</strong> The interactive shell is used to upload privilege escalation exploits, dump credentials (using Mimikatz), and launch further attacks against internal network resources that are otherwise isolated from the internet.</li>\n</ul>\n\n<h3>Threat Assessment</h3>\nThe presence of an active reverse shell (Shellme) is a \"glass break\" incident. It means an attacker has bypassed all preventative security controls and possesses interactive, real-time access to the environment. Data exfiltration, lateral movement, or ransomware deployment are imminent.\n\n<h3>Incident Response and Remediation</h3>\n<ul>\n<li><strong>Immediate Isolation:</strong> The absolute highest priority is to sever the interactive connection. Isolate the infected machine from the network immediately.</li>\n<li><strong>Forensic Triage:</strong> Do not reboot the machine, as the shell is likely running entirely in memory and the process details will be lost. Use memory forensics to identify the parent process of the shell to determine *how* the attacker initially compromised the system.</li>\n<li><strong>Enterprise Credential Reset:</strong> If the shell was running under a privileged account (or if the attacker successfully escalated privileges), all domain and local credentials associated with that system must be considered compromised and reset immediately.</li>\n</ul>",
  "cta": "Published by the SystemHelpdesk team.",
  "aliases": [
    "HackTool.Shellme",
    "Backdoor.ReverseShell",
    "Win32/Shellme"
  ],
  "enrichment_level": "expert-seo",
  "faq": [
    {
      "@type": "Question",
      "name": "What is Shellme and what threat category does it belong to?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Shellme is classified as a Ransomware. Documented across security telemetry, it is engineered to execute unauthorized operations, establish persistent footholds on target endpoints, and facilitate malicious campaigns targeting enterprise and individual environments."
      }
    },
    {
      "@type": "Question",
      "name": "How does Shellme establish persistence and evade defensive controls?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Shellme typically establishes persistence through registry run keys, scheduled tasks, or service installations, while evading signature-based antivirus solutions through code obfuscation, memory injection, or anti-analysis sandbox checks."
      }
    },
    {
      "@type": "Question",
      "name": "What are the essential incident response steps for mitigating a Shellme compromise?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Security teams responding to Shellme should immediately isolate affected endpoints from the network, perform memory triage to capture volatile forensic artifacts, audit registry and startup persistence mechanisms, revoke exposed user credentials, and restore systems from verified, clean backups."
      }
    },
    {
      "@type": "Question",
      "name": "What cryptographic algorithms and file targeting techniques does HackTool.Shellme employ during execution?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "HackTool.Shellme typically leverages hybrid cryptographic architectures combining symmetric stream or block ciphers (such as AES-256 or ChaCha20) for rapid file encryption with asymmetric algorithms (such as RSA-2048 or Curve25519) to securely protect the session keys. It aggressively targets sensitive file extensions including corporate documents, databases, virtual disks, and backups while systematically executing commands to delete Volume Shadow Copies (vssadmin delete shadows /all /quiet) and disable system recovery options."
      }
    },
    {
      "@type": "Question",
      "name": "Are decryptors available for HackTool.Shellme, and what is the recommended recovery procedure?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Decryption availability for HackTool.Shellme depends on whether security researchers or law enforcement (such as the No More Ransom initiative) have recovered the master private keys or discovered flaws in its key generation routines. Victims should never pay the extortion demand, as payment fuels criminal operations without guaranteeing file restoration. The recommended recovery procedure entails isolating infected hosts, conducting forensic disk imaging, identifying the root access vector, and restoring validated systems from immutable offline backups."
      }
    }
  ],
  "faq_count": 5,
  "mitre_attack": [
    "T1059",
    "T1059.003",
    "T1090"
  ],
  "cisa_advisory": null,
  "last_updated": "2026-10-15",
  "type": "HackTool / Reverse Shell Backdoor",
  "target_industries": [
    "Healthcare",
    "Critical Infrastructure",
    "Enterprise"
  ],
  "motivation": "Financial Extortion",
  "threat_actors": [
    "Unknown / Cybercriminal"
  ],
  "target_geographies": [
    "Global"
  ],
  "attack_stage": [
    "defense_evasion",
    "impact"
  ],
  "ecosystem": [
    "windows_pe"
  ],
  "is_emerging": false,
  "mitre_attack_detail": [
    {
      "id": "T1059",
      "name": "Command and Scripting Interpreter",
      "tactic": "Execution"
    },
    {
      "id": "T1059.003",
      "name": "Command and Scripting Interpreter: Windows Command Shell",
      "tactic": "Execution"
    },
    {
      "id": "T1090",
      "name": "Proxy",
      "tactic": "Command and Control"
    }
  ],
  "containment_steps": [
    "Immediately isolate affected host(s) from the internal network (disconnect physical Ethernet and disable Wi-Fi/Bluetooth) to prevent Shellme from spreading laterally or encrypting network-attached storage (NAS) and shared SMB volumes.",
    "Preserve volatile system memory (RAM capture) on a representative endpoint before attempting a reboot or power-down, as Shellme symmetric encryption keys or uncompiled payload components may still reside in memory.",
    "Audit process execution logs and terminate active scripting interpreters (e.g. PowerShell, CMD, WScript) or commands executing 'vssadmin.exe delete shadows' or 'wbadmin' used by Shellme to inhibit recovery.",
    "Investigate the initial compromise vector (such as exposed RDP instances, spearphishing attachments, or vulnerable edge gateways) and enforce an immediate credential reset for all compromised Active Directory accounts.",
    "Restore critical assets and databases exclusively from verified, air-gapped, or immutable offline backups once the Shellme binary and related persistence hooks are eradicated."
  ],
  "what_to_avoid": [
    "Do not restart or power cycle infected systems prematurely; doing so destroys volatile RAM encryption keys and may trigger bootloader locking logic embedded in Shellme.",
    "Avoid negotiating or paying the extortion demand without prior forensic evaluation and consultation with incident response specialists, as payment does not guarantee data recovery.",
    "Do not connect clean backup drives or external storage to the affected network until Shellme eradication is completely verified."
  ],
  "target_platforms": [
    "Windows 11",
    "Windows 10",
    "Windows Server 2022",
    "Windows Server 2019"
  ]
}