Bebloh

Overview

Trojan:Win32/Bebloh (frequently referred to as **URLZone**) is a highly sophisticated, financially motivated Banking Trojan. It gained notoriety for pioneering advanced 'Web Injection' techniques. Bebloh doesn't just steal passwords; it actively manipulates the HTML and JavaScript of banking portals *while the victim is viewing them*. This allows the malware to execute illicit fund transfers in the background, while simultaneously altering the displayed web page to show a fake, healthy account balance to the user.

Understanding Bebloh (Web Injections)
To an end-user, the banking experience appears completely normal, even after their account has been drained. For a security analyst, Bebloh represents an apex predator in the financial malware space. It utilizes Man-in-the-Browser (MitB) tactics (`T1185`) to intercept and alter HTTP/HTTPS traffic locally, rendering server-side fraud detection (like IP geolocation or velocity checks) ineffective because the fraudulent transactions originate from the victim's trusted machine and active session.

Execution and Hooking Mechanics
Bebloh is typically delivered via spear-phishing campaigns (`T1566.001`) utilizing weaponized Office macros. Upon execution, it achieves persistence via the Registry Run keys (`T1547.001`) and injects its core DLL into the memory of all running web browsers (Chrome, Firefox, IE) (`T1055.001`). Once injected, it hooks essential networking APIs (like `HttpSendRequest` in `wininet.dll` or `PR_Write` in Firefox's NSS library) (`T1056.004`). When the victim navigates to a targeted banking URL, Bebloh requests customized web-injection scripts from its C2 server. These scripts dynamically alter the DOM, injecting fake input fields (to steal 2FA tokens) and rewriting account balance variables before the page is rendered.

Indicators of Compromise & Impact
The impact is direct, stealthy financial theft. Host-based IoCs include EDR alerts for DLL injection originating from `explorer.exe` into browser processes. Network IoCs involve the downloading of configuration files (often encrypted) from known Bebloh C2 infrastructure. Memory analysis will reveal hooked API functions within the browser process space.

MITRE ATT&CK Techniques

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

Tactical Mitigations

Based on the techniques used by this family, consider the following defensive strategies:

• T1056.004: Monitor for unauthorized keylogging, screen capturing, or web browser API hooking. Deploy EDR to detect API hooking.
• T1185: Enforce strong MFA and use browser isolation or hardened browsers for sensitive financial or administrative portals to defeat session hijacking.
• T1566.001: Scan email attachments for malicious macros, scripts, or suspicious archive files.

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

Sigma Rule

title: Suspicious Bebloh Activity
id: b70fc8146d99107712e070328deaed79
status: experimental
description: Detects generic indicators of the bebloh malware family.
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith:
            - '\cmd.exe'
            - '\powershell.exe'
        CommandLine|contains:
            - "*bebloh*"
    condition: selection
level: medium

Containment & Response Steps

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

1. Immediately isolate the endpoint; any active browser sessions on that machine are compromised and actively manipulated.
2. Contact the associated financial institutions immediately to freeze the victim's accounts and halt any pending transfers.
3. Initiate a mandatory password reset and 2FA token revocation from a *clean, uninfected* device.
4. Wipe the infected machine entirely; relying on AV removal is risky given the deep API hooking and potential for secondary payloads.

What to Avoid

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

1. Do not trust the account balances or transaction histories displayed on the infected machine's web browser.
2. Avoid relying solely on network-based fraud detection; MitB attacks originate from the victim's legitimate IP and session.

References & External Analysis

• Search "bebloh" on VirusTotal (External Analysis)

Frequently Asked Questions

Related Families (Category: trojan)

Explore other malware families in the same category:

• Hostseditor
• Havex
• Socstealer
• Informer
• Snare

Machine-readable

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