Hpursnif

Overview

Executive Summary

Propagation and Execution Lifecycle

• Advanced Evasion and Fileless Execution: Modern variants of Hpursnif rely heavily on "fileless" techniques. The initial macro executes PowerShell scripts that download and inject the Hpursnif DLL directly into memory (often into legitimate processes like `explorer.exe`), leaving minimal footprint on the hard drive to evade static antivirus detection.
• Web Injection and MitB Attacks: Hpursnif is a classic Man-in-the-Browser (MitB) threat. It hooks into browser APIs (Chrome, Firefox, IE) to intercept web traffic. It injects malicious HTML/JavaScript into legitimate banking websites, allowing attackers to steal login credentials, intercept 2FA tokens, and silently alter wire transfer details in real-time.
• Data Exfiltration: Beyond banking, Hpursnif acts as a comprehensive info-stealer, harvesting email credentials, system information, and digital certificates, exfiltrating this data to command-and-control (C2) servers hidden behind Tor or fast-flux networks.

Threat Assessment

Eradication and Incident Response

• Immediate Network Containment: The infected machine must be immediately physically disconnected from the network to halt active financial data exfiltration and prevent the trojan from pivoting laterally.
• Financial Account Lockdown: Immediately notify the organization's financial institutions to freeze all associated corporate accounts and closely monitor for unauthorized wire transfers.
• System Wipe and Re-image: Attempting to "clean" an Hpursnif infection using antivirus software is highly ineffective due to its in-memory execution and deep system hooks. The only guaranteed method of eradication is a complete wipe and re-image of the compromised host from a known good baseline.

Known aliases

Threat reports may refer to this family under multiple names:

• Trojan.Ursnif
• Banker.Gozi
• Win32/ISFB
• Trojan-Banker.Win32.Ursnif

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:

• 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.

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_HPURSNIF_T1_ARTIFACT {
    meta:
        description = "Tier 1 Primitive Artifact: Raw string matches for Hpursnif"
        tier = "T1 - Primitive Artifact"
        confidence = "Low-Medium (Fast Triage)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    strings:
        $s1 = "hpursnif" ascii wide nocase
        $s2 = "trojan.ursnif" ascii wide nocase
        $s3 = "banker.gozi" ascii wide nocase
        $s4 = "win32/isfb" ascii wide nocase
        $s5 = "trojan-banker.win32.ursnif" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

title: SystemHelpDesk Detection - Hpursnif (Trojan) Execution & Triage
id: 7b24d4ae-69e2-517a-8b26-d34e6173680a
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
  with the Hpursnif 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/hpursnif
- https://malware-families-catalog.systemhelpdesk.com/defensive/downloader-dropper-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
- author.ricky-jordan
- source.systemhelpdesk-mfc
- attack.t1056_004
- attack.t1185
- attack.t1114
- attack.t1055_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: medium

rule MALWARE_WIN_HPURSNIF_T3_ATTRIBUTION {
    meta:
        description = "Tier 3 Attribution Fingerprint: Heuristic detection for Hpursnif 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 = "hpursnif" 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. Sever network connectivity for the flagged endpoint to terminate persistent command-and-control (C2) communication channels and stop Hpursnif from retrieving secondary stage payloads.
2. Capture process memory triage to detect and terminate malicious threads injected by Hpursnif into legitimate system processes such as explorer.exe or svchost.exe.
3. Audit Windows Registry Run keys (HKCU\Software\Microsoft\Windows\CurrentVersion\Run) and Task Scheduler entries to locate and purge Hpursnif persistence hooks.
4. Deploy updated enterprise EDR detection signatures and conduct an out-of-band endpoint scan to isolate dropped binaries and staged payloads.
5. Rotate all credentials, domain user passwords, and session cookies active on the system during the Hpursnif execution timeframe.

What to Avoid

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

1. Do not assume the incident is resolved simply because an antivirus tool removed the initial Hpursnif dropper; always verify that secondary payloads and persistence hooks have been eradicated.
2. Avoid logging in with Domain Admin or privileged credentials on a machine suspected of running Hpursnif until memory triage is complete.
3. Do not delay host isolation; automated lateral movement and credential dumping can occur within minutes of initial execution.

References & External Analysis

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

Frequently Asked Questions

Related Threats (Category: Trojan)

Explore other documented threats in the same operational category:

• Rkit
• Delfinject
• Genericrxge
• Redirected
• Peflog
• Plead
• Be3Auestydmi
• Rodecap

Machine-readable

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