Spora

Overview

Ransom:Win32/Spora is widely regarded by threat analysts as one of the most sophisticated, 'professionally' developed crypto-ransomware families of its era. It gained notoriety not just for its robust RSA/AES encryption, but for its highly polished, consumer-friendly payment portal that offered a menu of extortion options, treating the victim more like a customer than a target.

Understanding Spora (Professional Ransomware)
To an end-user, Spora presents a catastrophic loss of data, coupled with a surprisingly professional, multi-lingual web interface (accessed via a dropped `.HTA` file). Spora was unique because it didn't just demand a flat fee; it offered 'a la carte' services. Victims could pay a large fee for a full system decryptor, a smaller fee to decrypt specific files, or a very small fee just to 'remove the virus' (without decrypting the data). For an enterprise, Spora was highly dangerous because it worked entirely offline after initial execution, requiring no C2 communication to encrypt files.

Execution and Extortion Mechanics
Spora was typically distributed via massive malspam campaigns featuring malicious invoices (often ZIP files containing HTA or JavaScript downloaders) (`T1566.001`). It was also heavily distributed via compromised websites offering fake Chrome font updates (the HoeflerText lure) (`T1189`). Upon execution, it does not require internet access (`T1486`). It generates a unique RSA key pair locally, encrypts the local private key with a hardcoded master public key, and then encrypts user files (`.doc`, `.xls`, `.pdf`, `.zip`, etc.) using AES-256. It modifies the registry to establish persistence (`T1547.001`) and famously deletes Volume Shadow Copies to prevent easy recovery (`T1490`). It does not append a new extension to encrypted files, but it drops a `.HTA` file containing the ransom portal.

Indicators of Compromise & Impact
The impact is severe, immediate data loss. Host-based IoCs include EDR alerts for `vssadmin.exe` execution, massive disk I/O, and the sudden appearance of the `.html` or `.hta` ransom notes on the desktop and in every encrypted directory. Network IoCs are minimal during encryption, as Spora is designed to operate offline.

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:

• T1566.001: Scan email attachments for malicious macros, scripts, or suspicious archive files.

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_SPORA_T1_ARTIFACT {
    meta:
        description = "Tier 1 Primitive Artifact: Raw string matches for Spora"
        tier = "T1 - Primitive Artifact"
        confidence = "Low-Medium (Fast Triage)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    strings:
        $s1 = "spora" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

title: SystemHelpDesk Detection - Spora (Ransomware) Execution & Triage
id: 3a519aaf-e618-5dbb-ab7a-67fa7ca75a63
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
  with the Spora 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/spora
- 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.t1189
- attack.t1566_001
- attack.t1490
- attack.t1486
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: critical

rule MALWARE_WIN_SPORA_T3_ATTRIBUTION {
    meta:
        description = "Tier 3 Attribution Fingerprint: Heuristic detection for Spora 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 = "spora" 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 physically disconnect the infected endpoint from the network to prevent the ransomware from traversing and encrypting SMB shares.
2. Identify the initial delivery vector (e.g., the fake font update or specific phishing email) and purge it from the environment.
3. Do NOT reboot the infected machine if possible; capture a live memory image (RAM dump).
4. Restore the encrypted systems from secure, offline backups that were isolated from the network at the time of the attack.

What to Avoid

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

1. Do not pay the ransom, even the 'smaller' fees offered by Spora's a la carte menu; it funds criminal operations and decryptors are never guaranteed.
2. Avoid assuming a machine is safe just because it is disconnected from the internet; Spora does not require a C2 connection to destroy data.

References & External Analysis

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

Frequently Asked Questions

Related Threats (Category: Ransomware)

Explore other documented threats in the same operational category:

• Hg8Absxocmcj
• Goppel
• Kykymber
• Offtoup
• Chekafev
• Conti
• Idsohtu
• Genericrxdr

Machine-readable

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