Diskscanfa

Overview

Executive Summary

Infection Vector and Technical Capabilities

• UI Subversion and Harassment: The malware launches a highly convincing, albeit fake, graphical interface resembling a Microsoft security product. It continuously bombards the user with high-priority alerts claiming the hard drive is failing, RAM is corrupted, or severe rootkits have been detected.
• System Lockdown: To force payment, DiskScanFA often blocks legitimate applications from launching. It intercepts executable launches (`.exe`) and displays a fake alert claiming the application is infected and must be blocked until the "premium" version is purchased.
• Security Disablement: The malware modifies the Windows Registry to disable the Task Manager, Registry Editor, and legitimate antivirus software to prevent the user from manually terminating the rogue process.

Threat Assessment

Incident Response and Remediation

• Safe Mode Triage: Because the rogue software blocks application execution, incident responders must boot the infected machine into Windows "Safe Mode with Networking" to bypass the malware's autostart mechanisms.
• Registry and File Eradication: In Safe Mode, utilize a reputable, enterprise-grade anti-malware scanner to locate and delete the hidden executables (often in `%AppData%`) and revert the malicious registry modifications (specifically `HKCU\Software\Microsoft\Windows\CurrentVersion\Run`).
• Credit Card Monitoring: If the user entered their credit card information into the fake software portal, they must immediately contact their bank, cancel the card, and monitor for fraudulent transactions.

Known aliases

Threat reports may refer to this family under multiple names:

• Rogue.DiskScanFA
• FakeAV.DiskScan
• Win32/FakeAV

MITRE ATT&CK Techniques

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

MITRE D3FEND™ Defensive Countermeasures

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

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_DISKSCANFA_T1_ARTIFACT {
    meta:
        description = "Tier 1 Primitive Artifact: Raw string matches for Diskscanfa"
        tier = "T1 - Primitive Artifact"
        confidence = "Low-Medium (Fast Triage)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    strings:
        $s1 = "diskscanfa" ascii wide nocase
        $s2 = "rogue.diskscanfa" ascii wide nocase
        $s3 = "fakeav.diskscan" ascii wide nocase
        $s4 = "win32/fakeav" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

title: SystemHelpDesk Detection - Diskscanfa (Advanced Threat) Execution & Triage
id: 35ff05b0-9480-50ad-b3fa-d6952835d156
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
  with the Diskscanfa malware family. Detects proxy execution, reflective DLL loading,
  and remote command injection associated with modular enterprise backdoors.
references:
- https://malware-families-catalog.systemhelpdesk.com/families/diskscanfa
- https://malware-families-catalog.systemhelpdesk.com/defensive/backdoor-rat-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.advanced-threat
- author.ricky-jordan
- source.systemhelpdesk-mfc
- attack.t1489
- attack.t1112
- attack.t1562_001
- attack.t1490
logsource:
  category: process_creation
  product: windows
detection:
  selection_process:
    Image|endswith:
    - \powershell.exe
    - \cmd.exe
    - \rundll32.exe
    - \regsvr32.exe
    CommandLine|contains:
    - DownloadString
    - IEX(
    - '/s /n /u /i:'
    - sc create
    - start-process
  condition: selection_process
falsepositives:
- Legitimate enterprise administrative scripts during approved change windows
- Authorized IT software deployment utilities and backup management agents
level: high

rule MALWARE_WIN_DISKSCANFA_T3_ATTRIBUTION {
    meta:
        description = "Tier 3 Attribution Fingerprint: Heuristic detection for Diskscanfa 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 = "diskscanfa" 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. Enforce forensic network isolation on all suspected endpoints while maintaining an out-of-band telemetry conduit to capture live Diskscanfa adversary activity.
2. Perform full memory dumps across identified staging nodes to extract memory-only implants, kernel rootkit hooks, and decrypted Diskscanfa C2 infrastructure IP/domain lists.
3. Review Active Directory domain controller authentication logs for anomalous Kerberos ticket requests (Pass-the-Ticket, Golden Ticket) and unauthorized DCSync operations associated with Diskscanfa.
4. Block all confirmed C2 domains, dynamic DNS endpoints, and proxy IP addresses across perimeter firewalls, proxies, and DNS security gateways.
5. Conduct an enterprise-wide sweep across surrounding subnets for secondary webshells, WMI event subscriptions, or remote execution tooling left behind by Diskscanfa operators.

What to Avoid

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

1. Do not assume the incident is resolved simply because an antivirus tool removed the initial Diskscanfa dropper; always verify that secondary payloads and persistence hooks have been eradicated.
2. Avoid logging in with Domain Admin or privileged credentials on a machine suspected of running Diskscanfa until memory triage is complete.
3. Do not delay host isolation; automated lateral movement and credential dumping can occur within minutes of initial execution.

References & External Analysis

• Search "diskscanfa" on VirusTotal (External Analysis)
• Search "diskscanfa" on Any.Run (Sandbox Sandbox)
• Search "diskscanfa" on MalwareBazaar (Malware Samples)

Frequently Asked Questions

Related Threats (Category: Advanced Threat)

Explore other documented threats in the same operational category:

• Doyo
• Lazagne
• Flvdownloader
• Stuxnet
• Systimizer
• Timesink
• Istbar
• Npack

Machine-readable

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