Pyfiledel

Overview

Trojan:Python/Pyfiledel is a highly destructive malware classified as a **Wiper**. Unlike ransomware, which encrypts files with the intention of extorting money for their return, a wiper is designed for pure sabotage. Its sole objective is to permanently delete or corrupt files, rendering the system completely unbootable or permanently destroying valuable intellectual property. The fact that it is written in Python indicates it is often deployed post-exploitation by attackers leveraging Living off the Land (LotL) techniques or pre-installed interpreters.

Understanding Pyfiledel (Wipers)
To an end-user, a Pyfiledel attack results in a totally destroyed system, often ending in a Blue Screen of Death (BSOD) or a 'Operating System not found' error upon reboot. For an enterprise, wipers are the most severe form of cyberattack, often associated with nation-state actors (like the NotPetya or Shamoon attacks) aiming to cause maximum operational disruption to critical infrastructure or to cover the tracks of a deeper espionage operation.

Execution and Destruction Mechanics
Pyfiledel is rarely a standalone executable; it is typically a Python script (`.py` or `.pyc`) deployed by an attacker who has already gained administrative access to the network (`T1059.006`). Upon execution, the script bypasses the standard Windows Recycle Bin. It utilizes Python's `os` and `shutil` modules to aggressively traverse the directory structure (`T1083`) and perform permanent deletions (`os.remove()`, `shutil.rmtree()`) (`T1485`). Advanced versions of Pyfiledel-like wipers may not just delete files, but actively overwrite the file contents with zeros or random data (file shredding) to thwart forensic data recovery tools (`T1485`). Furthermore, it may attempt to corrupt the Master Boot Record (MBR) or delete critical system files in `C:\Windows\System32` to guarantee the machine cannot be restarted (`T1561.002`).

Indicators of Compromise & Impact
The impact is catastrophic, irreversible data destruction. Host-based IoCs include EDR alerts for Python executing script files from temporary directories, massive and rapid file deletion events across the filesystem, and the sudden termination of critical system processes leading to system crashes. Because wipers destroy the very logs needed to investigate them, detecting the *initial* intrusion is paramount.

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:

• T1059.006: Restrict execution of scripting languages such as PowerShell, VBScript, or Python to authorized administrators. Enforce Script Block Logging.

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_PYFILEDEL_T1_ARTIFACT {
    meta:
        description = "Tier 1 Primitive Artifact: Raw string matches for Pyfiledel"
        tier = "T1 - Primitive Artifact"
        confidence = "Low-Medium (Fast Triage)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    strings:
        $s1 = "pyfiledel" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

title: SystemHelpDesk Detection - Pyfiledel (Ransomware) Execution & Triage
id: cd435376-c30f-5a1f-a5b9-95bb5bf81179
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
  with the Pyfiledel 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/pyfiledel
- 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.t1485
- attack.t1059_006
- attack.t1561_002
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_PYFILEDEL_T3_ATTRIBUTION {
    meta:
        description = "Tier 3 Attribution Fingerprint: Heuristic detection for Pyfiledel 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 = "pyfiledel" 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. If a wiper attack is detected in progress, immediately pull the power cords (do NOT perform a graceful shutdown) on critical servers to halt the overwriting process.
2. Physically isolate the affected network segments to prevent the attacker from deploying the Python script to other subnets.
3. Initiate disaster recovery protocols to restore systems from secure, offline backups (e.g., tape backups or immutable cloud storage).
4. Conduct a deep forensic investigation on surviving network appliances (firewalls, proxies) to determine how the attacker gained the administrative access required to deploy the wiper.

What to Avoid

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

1. Do not assume data can be easily recovered using standard undelete tools; wipers specifically overwrite the data blocks on the hard drive.
2. Avoid restoring backups to the same network environment without first identifying and closing the initial breach vector, or the attacker will simply wipe the restored servers.

References & External Analysis

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

Frequently Asked Questions

Related Threats (Category: Ransomware)

Explore other documented threats in the same operational category:

• Cakl
• Opesup
• Tufik
• Activator
• Ranapama
• Hype
• Zxrloader
• Emogen

Machine-readable

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