Ransomkd
Table of Contents
Overview
Ransom:Win32/Ransomkd is a generic heuristic detection used by antivirus engines to identify executables that exhibit behavior typical of **Cryptographic Ransomware**. Because it is a generic detection, it does not identify a specific, well-known family (like Ryuk or LockBit), but rather flags the *action* of mass file encryption occurring on the system.
Understanding Ransomkd (Generic Ransomware)
To an end-user, the impact is devastating: personal documents, photos, and databases are suddenly inaccessible, appended with an unknown file extension, and a ransom note (often a `.txt` or `.hta` file) appears on the desktop demanding cryptocurrency payment for the decryption key. For a security analyst, a 'Ransomkd' detection means a severe breach has already progressed to its final, most destructive stage.
Execution and Encryption Mechanics
The delivery method varies (malspam, RDP brute-forcing, exploiting unpatched vulnerabilities). Upon execution, the malware establishes persistence (`T1547.001`) and immediately begins iterating through the file system and mapped network drives (`T1083`). It employs the Windows CryptoAPI or embedded cryptographic libraries (like AES or RSA) to rapidly encrypt files matching specific extensions (e.g., `.docx`, `.sql`, `.pdf`) (`T1486`). Crucially, to prevent easy recovery, the malware actively inhibits system recovery by deleting Volume Shadow Copies (`vssadmin.exe delete shadows`), disabling Windows Recovery Environment (`reagentc.exe /disable`), and clearing event logs (`T1490`).
Indicators of Compromise & Impact
The impact is total loss of data availability and severe business interruption. Host-based IoCs include EDR alerts for mass file modification events (high I/O activity), the execution of `vssadmin` or `bcdedit` commands by unknown processes, the appearance of ransom notes (`RESTORE_FILES.txt`), and the modification of file extensions across user directories. Network IoCs may include connections to Tor gateways or hardcoded IP addresses for key exchange prior to encryption.
MITRE ATT&CK Techniques
Observed techniques used by this family, mapped to our technical analysis hubs and the official MITRE ATT&CK framework:
| Technique | Name | Tactic | Official Spec |
|---|---|---|---|
T1486 | Data Encrypted for Impact | Impact | ATT&CK ↗ |
T1490 | Inhibit System Recovery (Deleting Shadow Copies) | Impact | ATT&CK ↗ |
T1083 | File and Directory Discovery (Scanning for files to encrypt) | Discovery | ATT&CK ↗ |
T1547.001 | Boot or Logon Autostart Execution | Persistence | ATT&CK ↗ |
MITRE D3FEND™ Defensive Countermeasures
Defensive techniques mapped to counter the offensive tradecraft observed in this family (via the MITRE D3FEND matrix):
| D3FEND ID | Countermeasure Name | Tactic | Countered ATT&CK | Defensive Guidance |
|---|---|---|---|---|
D3-FDA | File Directory Access Auditing | Detect | T1083 | Audit and alert on high-frequency recursive directory queries executed by non-system and unclassified binaries. |
D3-FAED | File Alteration Early Detection | Detect | T1486 | Deploy canary files and monitor mass rename/encryption I/O spikes to terminate ransomware threads immediately. |
D3-VSS | Volume Shadow & Snapshot Hardening | Harden | T1490 | Block execution of vssadmin.exe and wmic shadowcopy delete; maintain air-gapped immutable backup repositories. |
D3-RPM | Registry Persistence Monitoring | Detect | T1547.001 | Audit and restrict write privileges to user and machine-level Registry Run/RunOnce keys using Endpoint Privilege Management. |
Tiered Detection Rules (Cisco CAIRN Model)
Modern threat detection requires multi-layered rule engineering. We classify detections into three operational tiers based on signal fidelity:
Tier 1 Primitive Artifact Rule (Fast Triage)
Matches raw strings and file markers. Vulnerable to binary repacking and simple obfuscation.
rule MALWARE_WIN_RANSOMKD_T1_ARTIFACT {
meta:
description = "Tier 1 Primitive Artifact: Raw string matches for Ransomkd"
tier = "T1 - Primitive Artifact"
confidence = "Low-Medium (Fast Triage)"
author = "SystemHelpdesk Threat Research Desk"
date = "2026-10-14"
strings:
$s1 = "ransomkd" ascii wide nocase
condition:
uint16(0) == 0x5a4d and any of them
}Tier 2 Behavioral Context Rule (Process Chains & Sigma)
Tracks parent-child process anomalies and suspicious scripting telemetry. Resilient against file renames.
title: SystemHelpDesk Detection - Ransomkd (Ransomware) Execution & Triage
id: aa7afe92-7d84-57c9-8a10-f4caf06e288f
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
with the Ransomkd malware family. Detects volume shadow copy deletion, boot status
tampering, and recovery inhibition characteristic of modern ransomware operations.
references:
- https://malware-families-catalog.systemhelpdesk.com/families/ransomkd
- https://malware-families-catalog.systemhelpdesk.com/defensive/ransomware-protection
- https://malware-families-catalog.systemhelpdesk.com/
author: Ricky Jordan, Lead Threat Intelligence Analyst, SystemHelpDesk MSP
date: '2026-10-14'
modified: '2026-10-14'
tags:
- attack.ransomware
- author.ricky-jordan
- source.systemhelpdesk-mfc
- attack.t1083
- attack.t1486
- attack.t1490
- attack.t1547_001
logsource:
category: process_creation
product: windows
detection:
selection_process:
Image|endswith:
- \vssadmin.exe
- \wmic.exe
- \wbadmin.exe
- \bcdedit.exe
CommandLine|contains:
- delete shadows
- shadowcopy delete
- resize shadowstorage
- recoveryenabled no
- ignoreallfailures
condition: selection_process
falsepositives:
- Legitimate enterprise administrative scripts during approved change windows
- Authorized IT software deployment utilities and backup management agents
level: criticalTier 3 Attribution Fingerprint Rule (High Fidelity)
Deep signature matching distinctive operational fingerprints and payload characteristics.
rule MALWARE_WIN_RANSOMKD_T3_ATTRIBUTION {
meta:
description = "Tier 3 Attribution Fingerprint: Heuristic detection for Ransomkd tradecraft"
tier = "T3 - Attribution Fingerprint"
confidence = "High (Confirmed Family Signature)"
author = "SystemHelpdesk Threat Research Desk"
date = "2026-10-14"
strings:
// Core family identifier & heuristic payload signatures
$attrib_str = "ransomkd" ascii wide nocase
$pe_magic = "MZ" ascii
$net_marker = "http" ascii nocase
condition:
uint16(0) == 0x5a4d and ($attrib_str and $net_marker) and filesize < 15MB
}Containment & Response Steps
Ordered checklist for responders. Adapt to your environment and engage professional support for active incidents.
- IMMEDIATELY physically disconnect the infected endpoint from the network (pull the Ethernet cable/disable Wi-Fi) to prevent the ransomware from encrypting shared network drives and lateral movement.
- Do not immediately reboot the machine; if the encryption process is ongoing, a reboot might finalize the destruction or trigger further payloads. Capture a live memory dump if possible to potentially recover encryption keys.
- Identify the specific strain of ransomware (by analyzing the ransom note or file extensions) and check resources like 'No More Ransom' to see if a free decryptor exists.
- Restore the affected systems from secure, offline backups (e.g., tape drives or immutable cloud storage) that were not accessible from the infected network.
What to Avoid
Common mistakes during response to this family that can destroy evidence, spread the infection, or worsen recovery.
- Do not pay the ransom; it funds criminal enterprises and there is no guarantee the attackers will provide a working decryption tool.
- Avoid reconnecting the machine to the network until it has been completely wiped and rebuilt from a known-clean image.
References & External Analysis
- Search "ransomkd" on VirusTotal (External Analysis)
- Search "ransomkd" on Any.Run (Sandbox Sandbox)
- Search "ransomkd" on MalwareBazaar (Malware Samples)
Frequently Asked Questions
What is Ransomkd and what threat category does it belong to?
Ransomkd 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.
How does Ransomkd establish persistence and evade defensive controls?
Ransomkd 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.
What are the essential incident response steps for mitigating a Ransomkd compromise?
Security teams responding to Ransomkd 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.
What cryptographic algorithms and file targeting techniques does Ransomkd employ during execution?
Ransomkd 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.
Are decryptors available for Ransomkd, and what is the recommended recovery procedure?
Decryption availability for Ransomkd 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.
How do I remove the Ransomkd Ransomware from Windows?
Manual removal of Ransomkd is highly discouraged as it may leave persistence mechanisms intact. We recommend disconnecting the device from the internet and utilizing a professional incident response service or enterprise-grade EDR software to conduct a full forensic sweep.
Is Ransomkd a virus or a Ransomware?
Ransomkd is classified as a Ransomware. Unlike traditional viruses that infect files, modern malware like Ransomkd typically operates as a standalone payload designed to compromise systems, steal data, or deploy secondary stage implants.
What are the main symptoms of a Ransomkd infection?
Symptoms of Ransomkd can include unexpected system slowness, unauthorized outbound network traffic to unknown IP addresses, disabled security software, and suspicious background processes running from AppData or Temp directories.
Protect Your Network Against Ransomwares
Want to prevent Ransomkd and similar threats from compromising your organization? Read our comprehensive defensive guide: Ransomware Containment & Incident Response.
📣 Threat Intel Correction or Update?
Notice an outdated IOC, unlisted alias, or disputed attribution? Threat researchers are invited to propose an update on GitHub or contact the SystemHelpDesk research desk. All community revisions are credited in our public CHANGELOG.
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Ecosystem & Interactive Environments
This profile is part of the Malware Families Catalog, a public dataset of 2,899 malware families. The catalog is also published across our ecosystem: Hugging Face, Kaggle, Zenodo, Replit, StackBlitz, CodeSandbox, and CodePen.