Staem
Overview
Executive Summary
"Staem" (a deliberate misspelling of "Steam") is a classification for a specific type of Phishing Trojan and Information Stealer designed to target users of the Valve Steam gaming platform. Its primary objective is the theft of Steam account credentials, bypassing Steam Guard (2FA), and ultimately stealing valuable in-game inventories (like CS:GO skins) and hijacking the account for resale.Infection Vector and Technical Capabilities
Staem trojans are heavily distributed via social engineering within the Steam community itself. Attackers compromise one account, then message the victim's friends list with links to fake tournament sign-ups, "free skin" giveaways, or deceptive trading sites. The malware is often disguised as a VoIP client (like a fake TeamSpeak or Discord update) required to join a game. Upon execution, it performs a highly targeted data harvesting operation:- Credential Phishing Overlays: The trojan often operates by detecting when the legitimate Steam client is launched. It then immediately suspends the legitimate process and overlays a pixel-perfect, fake Steam login window on top. When the user enters their username and password, it is captured by the malware.
- Steam Guard Bypass (SSFN File Theft): To bypass Steam's two-factor authentication, the malware actively hunts for the hidden `ssfn*` files located in the Steam installation directory. These files act as persistent authorization tokens.
- Data Exfiltration: The stolen credentials and the `ssfn` files are bundled and transmitted to the attacker's C2 server. The attacker can then use these files to log into the victim's account from a remote machine without triggering a Steam Guard code request.
Threat Assessment
While a Staem infection primarily targets personal gaming assets rather than corporate financial data, it represents a significant security breach. The hijacked account is immediately used to spread the malware further. Furthermore, users frequently reuse passwords; a compromised gaming password could lead to the compromise of the user's primary email or banking accounts.Incident Response and Remediation
- Immediate Account Recovery: The victim must immediately attempt to recover their account via Steam Support, locking the account to prevent the trade of valuable inventory items.
- Global Credential Reset: A complete password reset for the Steam account and ANY other service that shares the same password must be performed from a *different, clean device*.
- Endpoint Eradication: Run a full system scan using a reputable enterprise antivirus solution to remove the Staem executable and any associated keylogging components.
Known aliases
Threat reports may refer to this family under multiple names:
MITRE ATT&CK Techniques
This family has been observed using the following ATT&CK techniques: T1555.003 T1539 T1056.002 T1114
Tactical Mitigations
Based on the techniques used by this family, consider the following defensive strategies:
- T1056.002: Monitor for unauthorized keylogging, screen capturing, or web browser API hooking. Deploy EDR to detect API hooking.
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_STAEM {
meta:
description = "Detects Staem (trojan)"
author = "SystemHelpdesk Boilerplate Generator"
date = "2026-07-06"
strings:
$s1 = "staem" ascii wide nocase
$s2 = "trojan.steamstealer" ascii wide nocase
$s3 = "pws.steam" ascii wide nocase
$s4 = "phish.staem" ascii wide nocase
condition:
uint16(0) == 0x5a4d and any of them
}Sigma Rule
title: Suspicious Staem Activity
id: 038950b90fc283235b3f0eab81b7d3db
status: experimental
description: Detects generic indicators of the staem malware family.
logsource:
category: process_creation
product: windows
detection:
selection:
Image|endswith:
- '\cmd.exe'
- '\powershell.exe'
CommandLine|contains:
- "*staem*"
- "*trojan.steamstealer*"
- "*pws.steam*"
- "*phish.staem*"
condition: selection
level: mediumReferences & External Analysis
- Search "staem" on VirusTotal (External Analysis)
Frequently Asked Questions
How do I remove the Staem Trojan from Windows?
Manual removal of Staem is highly discouraged as it may leave persistence mechanisms intact. We recommend disconnecting the device from the internet and utilizing a professional incident response service or enterprise-grade EDR software to conduct a full forensic sweep.
Is Staem a virus or a Trojan?
Staem is classified as a Trojan. Unlike traditional viruses that infect files, modern malware like Staem typically operates as a standalone payload designed to compromise systems, steal data, or deploy secondary stage implants.
What are the main symptoms of a Staem infection?
Symptoms of Staem can include unexpected system slowness, unauthorized outbound network traffic to unknown IP addresses, disabled security software, and suspicious background processes running from AppData or Temp directories.
Related Families (Category: trojan)
Explore other malware families in the same category:
Protect Your Network Against Trojans
Want to prevent Staem and similar threats from compromising your organization? Read our comprehensive defensive guide: Banking Trojan Protection.
Machine-readable
Get this profile as JSON: https://jordanricky1604-ship-it.github.io/malware-families-catalog/api/staem.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.