Diskwriter
Table of Contents
Overview
Diskwriter (classified across cybersecurity databases under designations including Trojan:Win32/Diskwriter, Wiper:Win32/Diskwriter, and Win32/Diskwriter) is an aggressive and destructive disk-wiping trojan designed to cause permanent data destruction on infected Windows computers. Distributed via weaponized spear-phishing campaigns and Trojanized utilities, Diskwriter requests elevated administrative privileges to acquire direct low-level device handles via CreateFileW targeting raw physical disks ('\\.\PhysicalDrive0') and logical volume sectors. The malware writes randomized bytes or zeros across the Master Boot Record (MBR), GUID Partition Table (GPT), and NTFS Master File Table (MFT) structures. Once the low-level disk structures are destroyed, Diskwriter triggers an immediate hard system reboot or fatal blue screen (BSOD) via NtRaiseHardError, rendering the machine completely unbootable and causing irrecoverable data loss.
Known aliases
Threat reports may refer to this family under multiple names:
Family Pedigree & Lineage
Malware authors regularly fork and iterate upon existing codebases. Observed upstream lineage and downstream variants for this family include:
Known Derivatives & Downstream Variants: Trojan:Win32/Diskwriter.A · Wiper:Win32/Diskwriter.B
MITRE ATT&CK Techniques
This family has been observed using the following ATT&CK techniques: T1561.001 · T1561.002 · T1529 · T1082 · T1106
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-SDA | System Discovery Analysis | Detect | T1082 | Alert on rapid enumerations of systeminfo, hostname, and registry hardware trees in short intervals. |
D3-SCA | System Call Analysis | Detect | T1106 | Leverage kernel-mode EDR sensors to detect unhooked direct system calls (Syscalls) designed to circumvent user-mode API monitoring. |
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_DISKWRITER_T1_ARTIFACT {
meta:
description = "Tier 1 Primitive Artifact: Raw string matches for Diskwriter"
tier = "T1 - Primitive Artifact"
confidence = "Low-Medium (Fast Triage)"
author = "SystemHelpdesk Threat Research Desk"
date = "2026-10-14"
strings:
$s1 = "diskwriter" ascii wide nocase
$s2 = "trojan:win32/diskwriter" ascii wide nocase
$s3 = "wiper:win32/diskwriter" ascii wide nocase
$s4 = "win32/diskwriter" ascii wide nocase
$s5 = "diskwriter wiper" ascii wide nocase
$s6 = "diskwriter mbr destroyer" 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 - Diskwriter (Trojan) Execution & Triage
id: 51e476c5-946e-572b-a5a6-2f30c19e0313
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
with the Diskwriter malware family. Detects suspicious execution from temporary
user directories with hidden window flags and background transfer utilities.
references:
- https://malware-families-catalog.systemhelpdesk.com/families/diskwriter
- https://malware-families-catalog.systemhelpdesk.com/defensive/downloader-dropper-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.trojan
- author.ricky-jordan
- source.systemhelpdesk-mfc
- attack.t1561_001
- attack.t1561_002
- attack.t1529
- attack.t1082
- attack.t1106
logsource:
category: process_creation
product: windows
detection:
selection_process:
Image|endswith:
- \cmd.exe
- \powershell.exe
- \cscript.exe
- \wscript.exe
CommandLine|contains:
- AppData\Local\Temp
- -WindowStyle Hidden
- /e:jscript
- bitsadmin /transfer
condition: selection_process
falsepositives:
- Legitimate enterprise administrative scripts during approved change windows
- Authorized IT software deployment utilities and backup management agents
level: mediumTier 3 Attribution Fingerprint Rule (High Fidelity)
Deep signature matching distinctive operational fingerprints and payload characteristics.
rule MALWARE_WIN_DISKWRITER_T3_ATTRIBUTION {
meta:
description = "Tier 3 Attribution Fingerprint: Heuristic detection for Diskwriter 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 = "diskwriter" 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
}References & External Analysis
- Microsoft Defender Threat Encyclopedia - Trojan:Win32/Diskwriter
- Trend Micro Threat Encyclopedia - Wiper.Win32.Diskwriter
- Search "diskwriter" on VirusTotal (External Analysis)
- Search "diskwriter" on Any.Run (Sandbox Sandbox)
- Search "diskwriter" on MalwareBazaar (Malware Samples)
Frequently Asked Questions
What is Trojan:Win32/Diskwriter?
Diskwriter is a destructive disk-wiping trojan that permanently destroys low-level MBR and partition structures to render endpoints unbootable.
How does Diskwriter destroy hard drive data?
It acquires direct raw handles to \\.\PhysicalDrive0 via CreateFileW and overwrites the MBR, GPT, and Master File Table with garbage bytes.
Can data wiped by Diskwriter be recovered?
Data overwritten on the physical drive sectors cannot be restored by software tools and must be recovered from external offline backups.
How is Diskwriter delivered to victim environments?
It is delivered through targeted spear-phishing attacks, malicious utility downloads, and secondary destructive stagers.
What defensive measures prevent Diskwriter attacks?
Restrict administrative privileges, enable UEFI Secure Boot, deploy EDR blocking raw disk writes, and maintain immutable offline backups.
How do I remove Diskwriter from Windows?
Manual removal of Diskwriter 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.
What are the main symptoms of a Diskwriter infection?
Symptoms of Diskwriter 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 Trojans
Want to prevent Diskwriter and similar threats from compromising your organization? Read our comprehensive defensive guide: Banking Trojan Protection for Businesses.
📣 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.
Machine-readable
Get this profile as JSON: https://malware-families-catalog.systemhelpdesk.com/api/diskwriter.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.