Udpos

Overview

Trojan:Win32/Udpos is a highly specialized piece of Point-of-Sale (PoS) malware designed explicitly to steal credit and debit card information from retail and hospitality environments. Unlike standard infostealers, Udpos utilizes 'RAM Scraping' (`T1005`) to locate and extract Track 1 and Track 2 payment card data directly from the memory of the PoS application *before* it can be encrypted by the operating system.

Understanding Udpos (RAM Scraping)
To the cashier and the customer, the transaction appears completely normal. For a retail organization, a Udpos infection is a catastrophic data breach leading to massive financial liability, PCI-DSS compliance failure, and severe reputational damage. The malware is designed to operate silently on Windows-based cash registers and payment terminals.

Execution and RAM Scraping Mechanics
Attackers typically gain access to the PoS environment via compromised remote access tools (like RDP or LogMeIn) (`T1133`) or by pivoting from a breach in the corporate network. Once deployed on the terminal, Udpos runs as a background service or injects itself into legitimate processes. It continuously scans the volatile memory (RAM) of specific processes (like the PoS application itself) searching for regular expressions that match the structure of magnetic stripe data (`T1005`). When a card is swiped, the data is briefly unencrypted in RAM; Udpos captures it, encrypts it locally, and saves it to a hidden log file. This file is then periodically exfiltrated via DNS tunneling (`T1071.004`) or HTTP POST requests to a C2 server.

Indicators of Compromise & Impact
The impact is the massive theft of consumer financial data. Host-based IoCs include EDR alerts for anomalous processes reading the memory of authorized PoS applications, the presence of unexpected executables or services on strictly controlled terminal equipment, and the creation of encrypted, growing `.log` or `.dat` files in hidden directories. Network IoCs include unexpected outbound HTTP or DNS traffic originating directly from the PoS VLAN (which should ideally be isolated from the internet).

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:

• T1071.004: Monitor network traffic for anomalous application layer protocols like non-standard HTTP/S patterns or unexpected DNS requests.

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_UDPOS_T1_ARTIFACT {
    meta:
        description = "Tier 1 Primitive Artifact: Raw string matches for Udpos"
        tier = "T1 - Primitive Artifact"
        confidence = "Low-Medium (Fast Triage)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    strings:
        $s1 = "udpos" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

title: SystemHelpDesk Detection - Udpos (Trojan) Execution & Triage
id: f5ecdefc-4d4c-5777-b5c0-3ddb5536afae
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
  with the Udpos 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/udpos
- 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.t1005
- attack.t1133
- attack.t1071_004
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_UDPOS_T3_ATTRIBUTION {
    meta:
        description = "Tier 3 Attribution Fingerprint: Heuristic detection for Udpos 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 = "udpos" 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. Immediately disconnect the compromised PoS terminal from the network to prevent further exfiltration of payment data.
2. Do not power off the terminal immediately; engage an Incident Response (IR) team to capture the RAM, as the malware resides in memory.
3. Review firewall rules and segment the PoS network (VLAN) so that terminals cannot communicate directly with the internet.
4. Mandate complex passwords and Multi-Factor Authentication (MFA) for all remote access tools (RDP, VNC) used to manage the PoS environment.

What to Avoid

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

1. Do not allow PoS terminals to be used for general web browsing or email, as this drastically increases the attack surface.
2. Avoid relying solely on basic antivirus on PoS systems; specialized Application Control (whitelisting) is required to block unauthorized executables like Udpos.

References & External Analysis

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

Frequently Asked Questions

Related Threats (Category: Trojan)

Explore other documented threats in the same operational category:

• Cidox
• Genericrxby
• Bytefence
• Sinique
• Pbot
• Bebloh
• Faketool
• Oepass

Machine-readable

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