Psyme
Table of Contents
Overview
Executive Summary
Psyme is a classification for a family of malicious Trojans that rely heavily on scripting languages—specifically VBScript (.vbs) and JavaScript (.js)—to execute their payloads. Rather than using compiled executables (.exe), Psyme leverages the native Windows Script Host (WSH) to download and execute secondary malware, making it a frequent component in drive-by downloads and exploit kits.Infection Vector and Technical Capabilities
Psyme is predominantly distributed via malicious websites (where the script is embedded directly into the HTML and executed via a browser vulnerability) or as an obfuscated script file attached to a phishing email (e.g., an invoice disguised as a `.pdf.vbs` file). Upon execution, Psyme leverages native Windows tools:- Living off the Land (LotL): By executing via `wscript.exe` or `cscript.exe`, Psyme bypasses basic executable whitelisting and often avoids heuristic detection by older AV engines that focus solely on PE files.
- Downloader Functionality: The script's primary function is to reach out to an attacker-controlled server (often using the `MSXML2.XMLHTTP` COM object) to download a secondary, more destructive payload (like a banking trojan or ransomware).
- File System and Registry Manipulation: The script typically saves the downloaded payload to the `%Temp%` or `%AppData%` directory, modifies the Registry to ensure persistence (e.g., adding an entry to the `Run` key), and then executes the payload using the `WScript.Shell` object.
Threat Assessment
A Psyme infection is a severe indicator of compromise (IoC) because it acts as the gateway for more destructive malware. The use of script-based downloaders is a common tactic for bypassing initial perimeter defenses and delivering ransomware payloads.Remediation and Eradication
- Endpoint Detection and Response (EDR): EDR solutions must be configured to monitor the behavior of script interpreters (`wscript.exe`, `cscript.exe`, `powershell.exe`), particularly when they attempt to establish outbound network connections or execute files in temporary directories.
- Network Isolation and Sweeps: Isolate the infected endpoint and conduct a thorough forensic sweep to identify the specific secondary payload that Psyme successfully downloaded and executed.
- System Hardening (GPO): To prevent future script-based attacks, configure Group Policy (GPO) to change the default file association for `.vbs` and `.js` files to open in Notepad rather than executing via WSH, and deploy Windows Defender Application Control (WDAC).
Known aliases
Threat reports may refer to this family under multiple names:
MITRE ATT&CK Techniques
Observed techniques used by this family, mapped to our technical analysis hubs and the official MITRE ATT&CK framework:
| Technique | Name | Tactic | Official Spec |
|---|---|---|---|
T1059.005 | Command and Scripting Interpreter: Visual Basic (VBScript within the ASP file) | Execution | ATT&CK ↗ |
T1059.007 | Command and Scripting Interpreter: JavaScript/JScript/AutoIt | Execution | ATT&CK ↗ |
T1105 | Ingress Tool Transfer | Command and Control | ATT&CK ↗ |
T1547.001 | Boot or Logon Autostart Execution: Registry Run Keys / Startup Folder | Persistence | ATT&CK ↗ |
Tactical Mitigations
Based on the techniques used by this family, consider the following defensive strategies:
- T1059.005: Restrict execution of scripting languages such as PowerShell, VBScript, or Python to authorized administrators. Enforce Script Block Logging.
- T1059.007: Restrict execution of scripting languages such as PowerShell, VBScript, or Python to authorized administrators. Enforce Script Block Logging.
- T1105: Implement network intrusion detection systems (NIDS) and host-based firewalls to block unauthorized inbound or outbound file transfers.
MITRE D3FEND™ Defensive Countermeasures
Defensive techniques mapped to counter the offensive tradecraft observed in this family (via the MITRE D3FEND matrix):
| D3FEND ID | Countermeasure Name | Tactic | Countered ATT&CK | Defensive Guidance |
|---|---|---|---|---|
D3-SEA | Script Execution Analysis | Detect | T1059.005 | Analyze script block syntax and command arguments at runtime to detect malicious automation. |
D3-NTI | Network Traffic Inspection | Detect | T1105 | Inspect deep packet payloads for anomalous staging binaries and unauthorized egress protocols. |
D3-RPM | Registry Persistence Monitoring | Detect | T1547.001 | Audit and restrict write privileges to user and machine-level Registry Run/RunOnce keys using Endpoint Privilege Management. |
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:
Tier 1 Primitive Artifact Rule (Fast Triage)
Matches raw strings and file markers. Vulnerable to binary repacking and simple obfuscation.
rule MALWARE_WIN_PSYME_T1_ARTIFACT {
meta:
description = "Tier 1 Primitive Artifact: Raw string matches for Psyme"
tier = "T1 - Primitive Artifact"
confidence = "Low-Medium (Fast Triage)"
author = "SystemHelpdesk Threat Research Desk"
date = "2026-10-14"
strings:
$s1 = "psyme" ascii wide nocase
$s2 = "js/psyme" ascii wide nocase
$s3 = "vbs/psyme" ascii wide nocase
$s4 = "trojandownloader:js/psyme" ascii wide nocase
$s5 = "win32/psyme" ascii wide nocase
condition:
uint16(0) == 0x5a4d and any of them
}Tier 2 Behavioral Context Rule (Process Chains & Sigma)
Tracks parent-child process anomalies and suspicious scripting telemetry. Resilient against file renames.
title: SystemHelpDesk Detection - Psyme (Ransomware) Execution & Triage
id: 7aef445b-213c-548b-bb80-e582d8a9d87a
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
with the Psyme malware family. Detects volume shadow copy deletion, boot status
tampering, and recovery inhibition characteristic of modern ransomware operations.
references:
- https://malware-families-catalog.systemhelpdesk.com/families/psyme
- https://malware-families-catalog.systemhelpdesk.com/defensive/ransomware-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.ransomware
- author.ricky-jordan
- source.systemhelpdesk-mfc
- attack.t1059_005
- attack.t1059_007
- attack.t1105
- attack.t1547_001
logsource:
category: process_creation
product: windows
detection:
selection_process:
Image|endswith:
- \vssadmin.exe
- \wmic.exe
- \wbadmin.exe
- \bcdedit.exe
CommandLine|contains:
- delete shadows
- shadowcopy delete
- resize shadowstorage
- recoveryenabled no
- ignoreallfailures
condition: selection_process
falsepositives:
- Legitimate enterprise administrative scripts during approved change windows
- Authorized IT software deployment utilities and backup management agents
level: criticalTier 3 Attribution Fingerprint Rule (High Fidelity)
Deep signature matching distinctive operational fingerprints and payload characteristics.
rule MALWARE_WIN_PSYME_T3_ATTRIBUTION {
meta:
description = "Tier 3 Attribution Fingerprint: Heuristic detection for Psyme 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 = "psyme" 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.
- Immediately isolate affected host(s) from the internal network (disconnect physical Ethernet and disable Wi-Fi/Bluetooth) to prevent Psyme from spreading laterally or encrypting network-attached storage (NAS) and shared SMB volumes.
- Preserve volatile system memory (RAM capture) on a representative endpoint before attempting a reboot or power-down, as Psyme symmetric encryption keys or uncompiled payload components may still reside in memory.
- Audit process execution logs and terminate active scripting interpreters (e.g. PowerShell, CMD, WScript) or commands executing 'vssadmin.exe delete shadows' or 'wbadmin' used by Psyme to inhibit recovery.
- Investigate the initial compromise vector (such as exposed RDP instances, spearphishing attachments, or vulnerable edge gateways) and enforce an immediate credential reset for all compromised Active Directory accounts.
- Restore critical assets and databases exclusively from verified, air-gapped, or immutable offline backups once the Psyme binary and related persistence hooks are eradicated.
What to Avoid
Common mistakes during response to this family that can destroy evidence, spread the infection, or worsen recovery.
- Do not restart or power cycle infected systems prematurely; doing so destroys volatile RAM encryption keys and may trigger bootloader locking logic embedded in Psyme.
- Avoid negotiating or paying the extortion demand without prior forensic evaluation and consultation with incident response specialists, as payment does not guarantee data recovery.
- Do not connect clean backup drives or external storage to the affected network until Psyme eradication is completely verified.
References & External Analysis
- Search "psyme" on VirusTotal (External Analysis)
- Search "psyme" on Any.Run (Sandbox Sandbox)
- Search "psyme" on MalwareBazaar (Malware Samples)
Frequently Asked Questions
What is Psyme and what threat category does it belong to?
Psyme is classified as a Ransomware. Documented across security telemetry, it is engineered to execute unauthorized operations, establish persistent footholds on target endpoints, and facilitate malicious campaigns targeting enterprise and individual environments.
How does Psyme establish persistence and evade defensive controls?
Psyme typically establishes persistence through registry run keys, scheduled tasks, or service installations, while evading signature-based antivirus solutions through code obfuscation, memory injection, or anti-analysis sandbox checks.
What are the essential incident response steps for mitigating a Psyme compromise?
Security teams responding to Psyme should immediately isolate affected endpoints from the network, perform memory triage to capture volatile forensic artifacts, audit registry and startup persistence mechanisms, revoke exposed user credentials, and restore systems from verified, clean backups.
What cryptographic algorithms and file targeting techniques does JS/Psyme employ during execution?
JS/Psyme typically leverages hybrid cryptographic architectures combining symmetric stream or block ciphers (such as AES-256 or ChaCha20) for rapid file encryption with asymmetric algorithms (such as RSA-2048 or Curve25519) to securely protect the session keys. It aggressively targets sensitive file extensions including corporate documents, databases, virtual disks, and backups while systematically executing commands to delete Volume Shadow Copies (vssadmin delete shadows /all /quiet) and disable system recovery options.
Are decryptors available for JS/Psyme, and what is the recommended recovery procedure?
Decryption availability for JS/Psyme depends on whether security researchers or law enforcement (such as the No More Ransom initiative) have recovered the master private keys or discovered flaws in its key generation routines. Victims should never pay the extortion demand, as payment fuels criminal operations without guaranteeing file restoration. The recommended recovery procedure entails isolating infected hosts, conducting forensic disk imaging, identifying the root access vector, and restoring validated systems from immutable offline backups.
How do I remove the Psyme Ransomware from Windows?
Manual removal of Psyme 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 Psyme a virus or a Ransomware?
Psyme is classified as a Ransomware. Unlike traditional viruses that infect files, modern malware like Psyme typically operates as a standalone payload designed to compromise systems, steal data, or deploy secondary stage implants.
What are the main symptoms of a Psyme infection?
Symptoms of Psyme 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.
Protect Your Network Against Ransomwares
Want to prevent Psyme and similar threats from compromising your organization? Read our comprehensive defensive guide: Ransomware Containment & Incident Response.
📣 Threat Intel Correction or Update?
Notice an outdated IOC, unlisted alias, or disputed attribution? Threat researchers are invited to propose an update on GitHub or contact the SystemHelpDesk research desk. All community revisions are credited in our public CHANGELOG.
Machine-readable
Get this profile as JSON: https://malware-families-catalog.systemhelpdesk.com/api/psyme.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.