Poscardstealer

Overview

Trojan:Win32/Poscardstealer (often representing families like BlackPOS, Dexter, or Alina) is a critical classification for **Point-of-Sale (PoS) RAM Scrapers**. This malware is specifically engineered to target retail cash registers, hospitality payment terminals, and restaurant management systems. Its sole objective is to scan the live memory (RAM) of the PoS system to locate, extract, and exfiltrate unencrypted credit and debit card Track 1 and Track 2 data before the transaction is finalized and encrypted.

Understanding PoS RAM Scraping
To a retail employee, the cash register functions normally. To the enterprise, Poscardstealer represents a catastrophic data breach, massive PCI-DSS compliance fines, and devastating reputational damage. Due to legacy payment processing architecture, even if credit card data is encrypted during network transit, it exists in plain text inside the PoS software's memory for a split second during authorization. RAM scrapers exploit this exact vulnerability.

Execution and Memory Scraping Mechanics
PoS systems are typically infected via lateral movement after an initial corporate network breach (`T1190`), or via compromised vendor remote access tools (like pcAnywhere or RDP) (`T1133`). Once installed on the Windows-based PoS terminal, the malware establishes persistence (`T1547.001`). It then continually enumerates running processes (specifically targeting retail software processes like `pos.exe` or `aloha.exe`) (`T1057`). It uses APIs like `ReadProcessMemory` (`T1005`) to dump the live RAM. It uses regular expressions (RegEx) to parse the memory dump, specifically searching for the structured patterns of credit card magnetic stripe data (Track 1/Track 2). It saves this stolen data to a hidden local file, which is periodically exfiltrated to the attacker's C2 server (`T1041`).

Indicators of Compromise & Impact
The impact is the mass theft of customer payment data. Host-based IoCs include EDR alerts for anomalous processes (even legitimate administrative tools) repeatedly calling `ReadProcessMemory` against retail application executables. The presence of hidden text or `.tmp` files containing raw credit card numbers or encrypted blobs in the PoS system's `%Temp%` directory is a definitive indicator. Network IoCs include unexpected outbound traffic from the highly restricted PoS VLAN to the internet.

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

Sigma Rule

title: Suspicious Poscardstealer Activity
id: ce5e983dc7aa209ce3c7ec3459506671
status: experimental
description: Detects generic indicators of the poscardstealer malware family.
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith:
            - '\cmd.exe'
            - '\powershell.exe'
        CommandLine|contains:
            - "*poscardstealer*"
    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 infected PoS terminals from the corporate network and the internet, but DO NOT power them off, as RAM forensics may be required.
2. Engage a specialized incident response firm and notify legal counsel and the acquiring bank, as this constitutes a major PCI breach.
3. Analyze firewall logs from the PoS VLAN to determine exactly how much data was exfiltrated and to what IP addresses.
4. Implement Point-to-Point Encryption (P2PE) hardware terminals, which encrypt the card data at the read head, rendering software-based RAM scrapers useless.

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 direct access to the internet; they should be strictly segmented in a dedicated VLAN with aggressive egress filtering.
2. Avoid running standard corporate AV on legacy PoS hardware without tuning; aggressive active scanning can crash critical retail transactions.

References & External Analysis

• Search "poscardstealer" on VirusTotal (External Analysis)

Frequently Asked Questions

Related Families (Category: trojan)

Explore other malware families in the same category:

• Gampass
• Mozla
• Esfury
• Shelma
• Xxybyu

Machine-readable

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