Magistrcorr

Overview

Executive Summary

Infection Vector and Technical Capabilities

• Polymorphic File Infection: Magistr infects PE (Portable Executable) files by injecting its code and altering the entry point. It is highly polymorphic, meaning the virus encrypts its own body with a different key for every infected file, making signature-based detection difficult.
• Mass-Mailing and Lateral Movement: It implements its own SMTP engine to mass-mail copies of infected files to harvested email addresses, utilizing the compromised host to attack external networks and internal peers.
• Destructive Payload (Time Bomb): The most critical threat is its delayed destructive payload. After a certain period (e.g., one month after initial infection), the virus attempts to overwrite the system's hard drive with garbage data (wiping the MBR and FAT) and attempts to flash (destroy) the motherboard's BIOS firmware, rendering the computer permanently unbootable (similar to the CIH/Chernobyl virus).

Threat Assessment

Incident Response and Remediation

• Immediate Isolation (Hard Stop): Instantly isolate the machine from the network. If the destructive payload is suspected to be active, a hard power-off is recommended to prevent the hard drive from being wiped.
• Forensic Triage: Boot the machine from a clean, offline environment (e.g., a Linux Live USB) to scan the drive and attempt data recovery before attempting any disinfection.
• Complete System Rebuild: Because Magistr deeply infects system executables and can damage firmware, attempting to "clean" the files is highly unreliable. The machine must be completely wiped, the BIOS flashed with a clean image from the manufacturer, and the OS re-installed from a known-good baseline.

Known aliases

Threat reports may refer to this family under multiple names:

• Virus.Win32.Magistr
• Worm.Magistr
• Win32/Magistr.corrupt

MITRE ATT&CK Techniques

Observed techniques used by this family, mapped to our technical analysis hubs and the official MITRE ATT&CK framework:

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_MAGISTRCORR_T1_ARTIFACT {
    meta:
        description = "Tier 1 Primitive Artifact: Raw string matches for Magistrcorr"
        tier = "T1 - Primitive Artifact"
        confidence = "Low-Medium (Fast Triage)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    strings:
        $s1 = "magistrcorr" ascii wide nocase
        $s2 = "virus.win32.magistr" ascii wide nocase
        $s3 = "worm.magistr" ascii wide nocase
        $s4 = "win32/magistr.corrupt" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

title: SystemHelpDesk Detection - Magistrcorr (Advanced Threat) Execution & Triage
id: d94e2f16-0136-5ea7-bbe9-13a921510e46
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
  with the Magistrcorr malware family. Detects proxy execution, reflective DLL loading,
  and remote command injection associated with modular enterprise backdoors.
references:
- https://malware-families-catalog.systemhelpdesk.com/families/magistrcorr
- https://malware-families-catalog.systemhelpdesk.com/defensive/backdoor-rat-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.advanced-threat
- author.ricky-jordan
- source.systemhelpdesk-mfc
- attack.t1485
- attack.t1561_002
- attack.t1055
logsource:
  category: process_creation
  product: windows
detection:
  selection_process:
    Image|endswith:
    - \powershell.exe
    - \cmd.exe
    - \rundll32.exe
    - \regsvr32.exe
    CommandLine|contains:
    - DownloadString
    - IEX(
    - '/s /n /u /i:'
    - sc create
    - start-process
  condition: selection_process
falsepositives:
- Legitimate enterprise administrative scripts during approved change windows
- Authorized IT software deployment utilities and backup management agents
level: high

rule MALWARE_WIN_MAGISTRCORR_T3_ATTRIBUTION {
    meta:
        description = "Tier 3 Attribution Fingerprint: Heuristic detection for Magistrcorr 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 = "magistrcorr" 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. Enforce forensic network isolation on all suspected endpoints while maintaining an out-of-band telemetry conduit to capture live Magistrcorr adversary activity.
2. Perform full memory dumps across identified staging nodes to extract memory-only implants, kernel rootkit hooks, and decrypted Magistrcorr C2 infrastructure IP/domain lists.
3. Review Active Directory domain controller authentication logs for anomalous Kerberos ticket requests (Pass-the-Ticket, Golden Ticket) and unauthorized DCSync operations associated with Magistrcorr.
4. Block all confirmed C2 domains, dynamic DNS endpoints, and proxy IP addresses across perimeter firewalls, proxies, and DNS security gateways.
5. Conduct an enterprise-wide sweep across surrounding subnets for secondary webshells, WMI event subscriptions, or remote execution tooling left behind by Magistrcorr operators.

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

Frequently Asked Questions

Related Threats (Category: Advanced Threat)

Explore other documented threats in the same operational category:

• Spytech
• Babar
• Primecasino
• Keybase
• Onescan
• Keyer
• Yahlover
• Directdownloader

Machine-readable

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