Facido
Table of Contents
Overview
Facido (cataloged across security vendors and threat intelligence databases under signatures including Trojan:Win32/Facido, TrojanDropper.Facido, and Dropper.Facido) is a stealthy Windows trojan dropper and initial access loader active since 2017. Designed to deploy high-severity secondary payloads while evading static antivirus detection, Facido is disseminated via weaponized email attachments, cracked software utilities, and drive-by web downloads. Upon execution, the malware profiles the host environment to detect analysis sandboxes, unpacks encrypted binaries embedded within its resource section into user temporary directories, and establishes persistence through Windows Registry Run keys before executing secondary malware payloads.
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/Facido.A · Trojandropper.Facido
MITRE ATT&CK Techniques
This family has been observed using the following ATT&CK techniques: T1105 · T1547.001 · T1071.001 · T1082 · T1027
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.
- T1105: Implement network intrusion detection systems (NIDS) and host-based firewalls to block unauthorized inbound or outbound file transfers.
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-BDA | Binary De-obfuscation & Unpacking | Analyze | T1027 | Utilize memory dump scanners and entropy inspection to unpack encrypted stagers during process creation. |
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-NTI | Network Traffic Inspection | Detect | T1105 | Inspect deep packet payloads for anomalous staging binaries and unauthorized egress protocols. |
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. |
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_FACIDO_T1_ARTIFACT {
meta:
description = "Tier 1 Primitive Artifact: Raw string matches for Facido"
tier = "T1 - Primitive Artifact"
confidence = "Low-Medium (Fast Triage)"
author = "SystemHelpdesk Threat Research Desk"
date = "2026-10-14"
strings:
$s1 = "facido" ascii wide nocase
$s2 = "trojan:win32/facido" ascii wide nocase
$s3 = "trojandropper.facido" ascii wide nocase
$s4 = "dropper.facido" ascii wide nocase
$s5 = "win32/facido" ascii wide nocase
$s6 = "trojan:win32/facido!rfn" 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 - Facido (Trojan Downloader) Execution & Triage
id: 1baa79c1-23d8-51cf-a901-0adaf80c39cd
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
with the Facido 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/facido
- 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.trojan-downloader
- author.ricky-jordan
- source.systemhelpdesk-mfc
- attack.t1105
- attack.t1547_001
- attack.t1071_001
- attack.t1082
- attack.t1027
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_FACIDO_T3_ATTRIBUTION {
meta:
description = "Tier 3 Attribution Fingerprint: Heuristic detection for Facido 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 = "facido" 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/Facido
- Search "facido" on VirusTotal (External Analysis)
- Search "facido" on Any.Run (Sandbox Sandbox)
- Search "facido" on MalwareBazaar (Malware Samples)
Frequently Asked Questions
What is Trojan:Win32/Facido?
Facido is a Windows trojan dropper and loader designed to decrypt and execute secondary malware payloads.
How does Facido infect endpoints?
It commonly infiltrates systems via freeware software bundlers, pirated application patches, and phishing links.
Where does Facido drop its execution artifacts?
It unpacks randomized staging binaries and configuration scripts into user %AppData% and %Temp% directories.
What secondary payloads are typically delivered by Facido?
It delivers secondary payloads including credential stealers, banking trojans, and crypto-ransomware.
How can defenders clean a Facido infection?
Run a Microsoft Defender Offline scan, clean the %Temp% directory, and remove unauthorized Registry Run keys.
What are the main symptoms of a Facido infection?
Symptoms of Facido 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 Trojan_Downloaders
Want to prevent Facido 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/facido.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.