{ "family": "ransim", "sample_count": 1, "category": "ransomware", "description": "

Executive Summary

\nRanSim (Ransomware Simulator) is technically a benign security testing tool designed by KnowBe4 to simulate ransomware behavior on endpoints. However, because its core function is to mimic the rapid file-encryption behaviors of actual ransomware (to test if local AV/EDR solutions can block it), it is frequently flagged by security software as \"HackTool\" or generic ransomware. While the tool itself is not malicious, its presence must be carefully contextualized.\n\n

Infection Vector and Technical Capabilities

\nRanSim is not \"infectious.\" It must be intentionally downloaded and executed by a user, typically a system administrator or security analyst running a controlled test. \n\nUpon execution, RanSim simulates various ransomware tactics:\n\n\n

Threat Assessment

\nRanSim itself poses zero threat to data availability or confidentiality. The \"threat\" is operational: if deployed widely without notifying the Security Operations Center (SOC), the simulated encryption behaviors can trigger massive cascades of high-severity alerts, causing panic and wasting incident response resources.\n\n

Incident Response and Remediation

\n", "cta": "Published by the SystemHelpdesk team.", "aliases": [ "HackTool.RanSim", "Riskware.RansomwareSimulator", "Win32/RanSim" ], "enrichment_level": "expert-seo", "faq": [ { "@type": "Question", "name": "What is Ransim and what threat category does it belong to?", "acceptedAnswer": { "@type": "Answer", "text": "Ransim 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 Ransim establish persistence and evade defensive controls?", "acceptedAnswer": { "@type": "Answer", "text": "Ransim 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 Ransim compromise?", "acceptedAnswer": { "@type": "Answer", "text": "Security teams responding to Ransim 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.RanSim employ during execution?", "acceptedAnswer": { "@type": "Answer", "text": "HackTool.RanSim 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.RanSim, and what is the recommended recovery procedure?", "acceptedAnswer": { "@type": "Answer", "text": "Decryption availability for HackTool.RanSim 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": [ "T1486", "T1490", "T1082", "T1027" ], "cisa_advisory": null, "last_updated": "2026-10-15", "type": "HackTool / Simulator", "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": "T1486", "name": "Data Encrypted for Impact", "tactic": "Impact" }, { "id": "T1490", "name": "Inhibit System Recovery (Behaviorally blocking the deletion of backups)", "tactic": "Impact" }, { "id": "T1082", "name": "System Information Discovery", "tactic": "Discovery" }, { "id": "T1027", "name": "Obfuscated Files or Information", "tactic": "Defense Evasion" } ], "containment_steps": [ "Immediately isolate affected host(s) from the internal network (disconnect physical Ethernet and disable Wi-Fi/Bluetooth) to prevent Ransim 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 Ransim 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 Ransim 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 Ransim 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 Ransim.", "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 Ransim eradication is completely verified." ], "target_platforms": [ "Windows 11", "Windows 10", "Windows Server 2022", "Windows Server 2019" ] }