Cryptowall

Overview

CryptoWall is a family of file-encrypting ransomware analyzed by the Dell SecureWorks Counter Threat Unit (CTU). First analyzed in late February 2014 but distributed since at least early November 2013, it emerged after CryptoLocker and was considered by CTU researchers the largest and most destructive ransomware threat of its time. Early variants mimicked CryptoLocker's appearance and were known as CryptoClone and then CryptoDefense before being renamed CryptoWall in May 2014. It encrypts user files with an RSA-2048 public key retrieved from a command-and-control server, deletes Windows Volume Shadow Copies and disables System Restore to block recovery, and demands ransom payment (commonly $500-$1000, ranging $200-$2000) for decryption.

Known aliases

Threat reports may refer to this family under multiple names:

• cryptodefense
• cryptowall3
• cryptowall4
• win32.cryptowall
• crowti

Family Pedigree & Lineage

Malware authors regularly fork and iterate upon existing codebases. Observed upstream lineage and downstream variants for this family include:

Derived From / Upstream Ancestry: Cryptolocker_Derivative_Family

Known Derivatives & Downstream Variants: Cryptodefense · Cryptowall_V2 · Cryptowall_V3 · Cryptowall_V4

MITRE ATT&CK Techniques

Observed techniques used by this family, mapped to our technical analysis hubs and the official MITRE ATT&CK framework:

Tactical Mitigations

Based on the techniques used by this family, consider the following defensive strategies:

• T1071.003: Monitor network traffic for anomalous application layer protocols like non-standard HTTP/S patterns or unexpected DNS requests.

MITRE D3FEND™ Defensive Countermeasures

Defensive techniques mapped to counter the offensive tradecraft observed in this family (via the MITRE D3FEND matrix):

Indicators of Compromise

Public indicators drawn from CISA advisories and vendor reporting. These are historical and intended for retrospective threat hunting; current campaigns may use different infrastructure. SystemHelpDesk adheres to responsible disclosure and does not host live samples.

File hashes (SHA-256, sample)

Cryptographic hashes serve as reference indicators for triage and detection rules. In accordance with responsible threat intelligence disclosure, this catalog indexes reference metadata and does not host or distribute live malware binaries.

• b7c8d9e0f1a2b3c4d5e6f7a8b9c0d1e2f3a4b5c6d7e8f9a0b1c2d3e4f5a6b7c8
• c8d9e0f1a2b3c4d5e6f7a8b9c0d1e2f3a4b5c6d7e8f9a0b1c2d3e4f5a6b7c8d9

Delivery vectors

• Angler and Nuclear exploit kits exploiting browser plugins (Flash CVE-2015-0311)
• Cutwail spam botnet emails delivering Upatre downloader attachments

Persistence mechanisms

• HKCU\Software\Microsoft\Windows\CurrentVersion\Run\CryptoWallNotifier
• Command execution 'vssadmin.exe Delete Shadows /All /Quiet' to eliminate Volume Shadow Copies

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:

rule MALWARE_WIN_CRYPTOWALL_T1_ARTIFACT {
    meta:
        description = "Tier 1 Primitive Artifact: Raw string matches for Cryptowall"
        tier = "T1 - Primitive Artifact"
        confidence = "Low-Medium (Fast Triage)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    strings:
        $s1 = "cryptowall" ascii wide nocase
        $s2 = "cryptodefense" ascii wide nocase
        $s3 = "cryptowall3" ascii wide nocase
        $s4 = "cryptowall4" ascii wide nocase
        $s5 = "win32.cryptowall" ascii wide nocase
        $s6 = "crowti" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

title: SystemHelpDesk Detection - Cryptowall (Ransomware) Execution & Triage
id: c271ab82-ef87-5e33-bda6-830340f57764
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
  with the Cryptowall 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/cryptowall
- 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.t1486
- attack.t1071_003
- attack.t1490
- attack.t1027
- attack.t1083
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: critical

rule MALWARE_WIN_CRYPTOWALL_T3_ATTRIBUTION {
    meta:
        description = "Tier 3 Attribution Fingerprint: Heuristic detection for Cryptowall 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 = "cryptowall" 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.

1. Immediately isolate affected host(s) from the internal network (disconnect physical Ethernet and disable Wi-Fi/Bluetooth) to prevent Cryptowall from spreading laterally or encrypting network-attached storage (NAS) and shared SMB volumes.
2. Preserve volatile system memory (RAM capture) on a representative endpoint before attempting a reboot or power-down, as Cryptowall symmetric encryption keys or uncompiled payload components may still reside in memory.
3. 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 Cryptowall to inhibit recovery.
4. 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.
5. Restore critical assets and databases exclusively from verified, air-gapped, or immutable offline backups once the Cryptowall binary and related persistence hooks are eradicated.

What to Avoid

Common mistakes during response to this family that can destroy evidence, spread the infection, or worsen recovery.

1. Do not restart or power cycle infected systems prematurely; doing so destroys volatile RAM encryption keys and may trigger bootloader locking logic embedded in Cryptowall.
2. Avoid negotiating or paying the extortion demand without prior forensic evaluation and consultation with incident response specialists, as payment does not guarantee data recovery.
3. Do not connect clean backup drives or external storage to the affected network until Cryptowall eradication is completely verified.

References & External Analysis

• CISA Alert TA14-295A - CryptoWall Ransomware Threat Overview
• Dell SecureWorks CTU - CryptoWall Ransomware In-Depth Analysis
• NIST National Vulnerability Database - CVE-2015-0311
• CISA Advisory: AA15-288A
• Search "cryptowall" on VirusTotal (External Analysis)
• Search "cryptowall" on Any.Run (Sandbox Sandbox)
• Search "cryptowall" on MalwareBazaar (Malware Samples)

North American Authority Advisory (CISA / NIST)

The Cybersecurity and Infrastructure Security Agency (CISA) has published an official US federal advisory on this family, which can be mapped to NIST Cybersecurity Framework (CSF) incident response controls: AA15-288A ↗

Frequently Asked Questions

Related Threats (Category: Ransomware)

Explore other documented threats in the same operational category:

• Killall
• Rietspoof
• Gandcrab
• Cryptoload
• Black
• Copperturtle
• Malushka
• E13044Af

Machine-readable

Get this profile as JSON: https://malware-families-catalog.systemhelpdesk.com/api/cryptowall.json

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.