Invader
Table of Contents
Overview
Invader (cataloged in antimalware repositories under signatures including Virus:Win32/Invader, Trojan:Win32/Invader, and Virus.Win32.Invader) is a sophisticated parasitic Windows PE file infector and memory-resident rootkit active since 2005. Once executed on a target machine, Invader injects a thread into the Windows kernel space or core system processes (services.exe, svchost.exe), hooking native file system APIs. Invader traverses local and mapped drives, searching for 32-bit Portable Executable (.exe) files. It prepends or appends polymorphic decryption routines to host binaries while relocating the original entry point (OEP), ensuring execution of its viral payload prior to passing control to the legitimate program. Invader disables system security notifications and blocks access to antivirus vendor update domains.
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: Virus:Win32/Invader.A · Virus:Win32/Invader.B
MITRE ATT&CK Techniques
This family has been observed using the following ATT&CK techniques: T1055.001 · T1547.001 · T1562.001 · T1082 · T1071.001
Tactical Mitigations
Based on the techniques used by this family, consider the following defensive strategies:
- T1071.001: Implement web filtering and SSL/TLS inspection to detect malicious command and control (C2) traffic hiding in HTTP/HTTPS.
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-DIA | DLL Injection Analysis | Detect | T1055.001 | Monitor remote thread creation (CreateRemoteThread) and unauthorized DLL loading into core Windows processes (svchost.exe, explorer.exe). |
D3-WAF | Web Content Filtering & Inspection | Filter | T1071.001 | Block newly registered domains (NRDs) and inspect HTTP Host and URI headers for known C2 profiles. |
D3-SDA | System Discovery Analysis | Detect | T1082 | Alert on rapid enumerations of systeminfo, hostname, and registry hardware trees in short intervals. |
D3-RPM | Registry Persistence Monitoring | Detect | T1547.001 | Audit and restrict write privileges to user and machine-level Registry Run/RunOnce keys using Endpoint Privilege Management. |
D3-STA | Security Tool Anti-Tamper Enforcement | Harden | T1562.001 | Block unauthorized modification of antivirus registry flags and prevent stopping security agent services. |
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_INVADER_T1_ARTIFACT {
meta:
description = "Tier 1 Primitive Artifact: Raw string matches for Invader"
tier = "T1 - Primitive Artifact"
confidence = "Low-Medium (Fast Triage)"
author = "SystemHelpdesk Threat Research Desk"
date = "2026-10-14"
strings:
$s1 = "invader" ascii wide nocase
$s2 = "virus:win32/invader" ascii wide nocase
$s3 = "trojan:win32/invader" ascii wide nocase
$s4 = "virus.win32.invader" ascii wide nocase
$s5 = "win32/invader" ascii wide nocase
$s6 = "w32/invader.virus" 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 - Invader (File Infector) Execution & Triage
id: 8c54dacf-6113-5975-afe6-4080f80b02c9
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
with the Invader 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/invader
- 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.file-infector
- author.ricky-jordan
- source.systemhelpdesk-mfc
- attack.t1055_001
- attack.t1547_001
- attack.t1562_001
- attack.t1082
- attack.t1071_001
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_INVADER_T3_ATTRIBUTION {
meta:
description = "Tier 3 Attribution Fingerprint: Heuristic detection for Invader 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 = "invader" 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 - Virus:Win32/Invader
- Trend Micro Threat Encyclopedia - PE_INVADER
- Search "invader" on VirusTotal (External Analysis)
- Search "invader" on Any.Run (Sandbox Sandbox)
- Search "invader" on MalwareBazaar (Malware Samples)
Frequently Asked Questions
What is Virus:Win32/Invader?
Invader is a parasitic Windows file infector that injects malicious code into PE executables and hooks system processes in memory.
How does Invader infect executable files?
It modifies the headers of target 32-bit PE executables, redirecting the Original Entry Point (OEP) to its polymorphic viral decryptor.
How does Invader maintain persistence on infected systems?
Because it infects existing legitimate Windows executables, it automatically executes whenever infected system or third-party applications run.
How does Invader defend against antivirus software?
It modifies the local hosts file to block connections to antimalware update servers and terminates security scanner processes.
How can an enterprise clean an Invader infection?
Boot into a clean Windows PE / offline recovery environment and use dedicated file disinfectors or restore clean system backups.
How do I remove the Invader File_Infector from Windows?
Manual removal of Invader 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.
Is Invader a virus or a File_Infector?
Invader is classified as a File_Infector. Unlike traditional viruses that infect files, modern malware like Invader typically operates as a standalone payload designed to compromise systems, steal data, or deploy secondary stage implants.
What are the main symptoms of a Invader infection?
Symptoms of Invader 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 File_Infectors
Want to prevent Invader and similar threats from compromising your organization? Read our comprehensive defensive guide: Think You've Been Hacked? What To Do First.
📣 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/invader.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.