Fraudkrypt

Overview

Ransomware:Win32/Fraudkrypt is a malicious hybrid that blends the extortion tactics of Scareware with the destructive capability of Ransomware. Its primary objective is to frighten the user into paying a fee by locking the screen or encrypting a subset of files (`T1486`), often using a heavily customized, deceptive GUI that mimics law enforcement agencies or fake antivirus alerts (`T1491.002`).

Understanding Fraudkrypt (Scareware/Ransomware)
To an end-user, Fraudkrypt is terrifying. They are presented with a full-screen, uncloseable window claiming they have committed a crime or their computer is hopelessly corrupted, demanding immediate payment (often via pre-paid cards or Bitcoin) to 'unlock' the system. For an IT department, Fraudkrypt variants vary wildly in severity; some merely lock the screen (easily bypassed), while others actively encrypt data.

Execution and Extortion Mechanics
Fraudkrypt is typically delivered via exploit kits, malicious downloads, or spam. Upon execution, it immediately alters the Windows Registry (e.g., changing the `Shell` or `Userinit` keys in `Winlogon`) (`T1547.004`) to ensure its lock-screen launches immediately upon boot, before the user can access the desktop. It then either encrypts files or simply hides them (`T1564.001`), replacing the wallpaper with its extortion demand. It disables Task Manager and Registry Editor to prevent the user from terminating the process.

Indicators of Compromise & Impact
The impact ranges from severe user distress and downtime to actual data loss if encryption is used. Host-based IoCs include the highly visible, often poorly translated extortion screen, unauthorized modifications to `Winlogon` registry keys, and the presence of suspicious executables in `%AppData%` or `%Startup%`. Network IoCs include connections to payment processing portals or C2 servers.

MITRE ATT&CK Techniques

Observed techniques used by this family, mapped to the MITRE ATT&CK framework:

Generated Detections (Boilerplate)

These YARA and Sigma rules are auto-generated based on the family name and aliases. They must be heavily tuned before deployment in a production environment.

YARA Rule

rule MALWARE_WIN_FRAUDKRYPT {
    meta:
        description = "Detects Fraudkrypt (ransomware)"
        author = "SystemHelpdesk Boilerplate Generator"
        date = "2026-07-06"
    strings:
        $s1 = "fraudkrypt" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

Sigma Rule

title: Suspicious Fraudkrypt Activity
id: f3ad36ec42d79a63cc30261ab6e695d0
status: experimental
description: Detects generic indicators of the fraudkrypt malware family.
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith:
            - '\cmd.exe'
            - '\powershell.exe'
        CommandLine|contains:
            - "*fraudkrypt*"
    condition: selection
level: medium

Containment & Response Steps

Ordered checklist for responders. Adapt to your environment and engage professional support for active incidents.

1. Attempt to boot the system into Safe Mode with Command Prompt; this often bypasses the Winlogon hooks Fraudkrypt uses to lock the screen.
2. If it's merely a screenlocker (Scareware), use `regedit` in Safe Mode to restore the `HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Shell` key back to `explorer.exe`.
3. If data is encrypted, check 'No More Ransom' to see if a free decryptor exists for the specific Fraudkrypt variant.
4. Run a full offline scan using a bootable AV rescue disk to remove the underlying malware executable.

What to Avoid

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

1. Under no circumstances should you pay the fine or ransom; it funds criminal operations and there is no guarantee the system will be unlocked.
2. Avoid reinstalling the OS immediately if data is encrypted; you may be able to recover the files if a decryptor becomes available later.

References & External Analysis

• Search "fraudkrypt" on VirusTotal (External Analysis)

Frequently Asked Questions

Related Families (Category: ransomware)

Explore other malware families in the same category:

• Dalt
• Mudrop
• Crastic
• Xorpix
• Pidmecc

Machine-readable

Get this profile as JSON: https://jordan123234-malware-families-explorer.static.hf.space/api/fraudkrypt.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.