Dyloader

Overview

Trojan:AndroidOS/Dyloader is a mobile banking trojan targeting the Android operating system. Unlike Windows-based banking trojans that rely on web injects, Dyloader represents the mobile-centric approach to financial theft: it utilizes deceptive Overlay Attacks (`T1636`) to steal credentials and aggressively abuses Android Accessibility Services (`T1628`) to intercept multi-factor authentication (MFA) SMS messages.

Understanding Dyloader (Android Banking Trojans)
To a mobile user, Dyloader typically masquerades as a legitimate application—often a utility app (like a PDF reader or Flash player) downloaded from a third-party app store or pushed via a phishing SMS (Smishing). For a threat analyst, Dyloader is a highly interactive threat where the attacker monitors the device in real-time, waiting for the user to open a targeted banking application.

Execution and Credential Theft Mechanics
Once installed, Dyloader immediately requests extensive permissions, most critically asking the user to enable Accessibility Services (`T1628`). With Accessibility enabled, the trojan gains near-total control over the device UI. When the user launches a targeted banking app, Dyloader detects the app launch and instantly draws a fake login screen *over* the legitimate app (`T1636`). The user unwittingly enters their credentials into the malware's overlay. The trojan then leverages its Accessibility permissions to silently read incoming SMS messages (`T1624.001`), capturing the bank's OTP/MFA codes and sending them to the attacker's C2 server to complete the fraudulent transaction.

Indicators of Compromise & Impact
The impact is direct financial theft and full compromise of the user's mobile banking identity. Device-based IoCs include applications requesting Accessibility Services that have no legitimate need for them (e.g., a 'Flashlight' app requesting screen reading permissions). A key behavioral indicator is a slight delay or 'flicker' when opening a banking application, signifying the overlay being drawn. Network IoCs include the device maintaining a constant heartbeat connection to an unknown C2 server via HTTPS.

MITRE ATT&CK Techniques

Observed techniques used by this family, mapped to the MITRE ATT&CK framework:

Generated Detections (Boilerplate)

These YARA and Sigma rules are auto-generated based on the family name and aliases. They must be heavily tuned before deployment in a production environment.

YARA Rule

rule MALWARE_WIN_DYLOADER {
    meta:
        description = "Detects Dyloader (trojan)"
        author = "SystemHelpdesk Boilerplate Generator"
        date = "2026-07-06"
    strings:
        $s1 = "dyloader" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

Sigma Rule

title: Suspicious Dyloader Activity
id: 27b90cee06675375d77adfb672d38085
status: experimental
description: Detects generic indicators of the dyloader malware family.
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith:
            - '\cmd.exe'
            - '\powershell.exe'
        CommandLine|contains:
            - "*dyloader*"
    condition: selection
level: medium

Containment & Response Steps

Ordered checklist for responders. Adapt to your environment and engage professional support for active incidents.

1. Boot the Android device into 'Safe Mode' (which disables third-party apps) to bypass the trojan's UI blocks.
2. Navigate to `Settings -> Accessibility` and immediately revoke Accessibility permissions from the suspicious application.
3. Go to `Settings -> Apps` and manually uninstall the malicious application.
4. Contact the affected financial institutions immediately to freeze accounts and report the compromised MFA tokens.

What to Avoid

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

1. Do not blindly grant Accessibility Services to applications; this is the most dangerous permission in the Android ecosystem.
2. Avoid downloading applications from untrusted third-party app stores or side-loading APKs sent via SMS.

References & External Analysis

• Search "dyloader" on VirusTotal (External Analysis)

Frequently Asked Questions

Related Families (Category: trojan)

Explore other malware families in the same category:

• Vesenlosow
• Termite
• Hideproc
• Bindjpg
• Autoitscript

Machine-readable

Get this profile as JSON: https://jordanricky1604-ship-it.github.io/malware-families-catalog/api/dyloader.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.