Elzob

Overview

Elzob (identified in security research telemetry as Ransom:Win32/Elzob, Trojan-Ransom.Win32.Elzob, and Win32/Elzob) is an aggressive Windows ransomware family active in opportunistic cybercrime attacks. Delivered via phishing campaigns and compromised freeware installers, Elzob scans local disk partitions, removable media, and mapped SMB shares for critical files including documents, spreadsheets, photos, and databases. It encrypts identified targets using symmetric encryption paired with public-key cryptography, renaming affected files with an extension such as .elzob or .locked. To maximize leverage and prevent local remediation, Elzob executes shell commands executing vssadmin to eliminate Volume Shadow Copies and modifies bootloader configurations via bcdedit to disable automated startup repairs. It leaves text extortion notes across encrypted directories directing victims to contact operators via Tor or darknet portals.

Known aliases

Threat reports may refer to this family under multiple names:

• Ransom:Win32/Elzob
• Trojan-Ransom.Win32.Elzob
• Win32/Elzob
• Ransom.Elzob
• Ransom:Win32/Elzob.A

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_ELZOB_T1_ARTIFACT {
    meta:
        description = "Tier 1 Primitive Artifact: Raw string matches for Elzob"
        tier = "T1 - Primitive Artifact"
        confidence = "Low-Medium (Fast Triage)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    strings:
        $s1 = "elzob" ascii wide nocase
        $s2 = "ransom:win32/elzob" ascii wide nocase
        $s3 = "trojan-ransom.win32.elzob" ascii wide nocase
        $s4 = "win32/elzob" ascii wide nocase
        $s5 = "ransom.elzob" ascii wide nocase
        $s6 = "ransom:win32/elzob.a" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

title: SystemHelpDesk Detection - Elzob (Ransomware) Execution & Triage
id: 54ed319f-12b8-5b01-90f4-e9d0d2cff6b1
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
  with the Elzob 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/elzob
- 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.t1486
- attack.t1490
- attack.t1566_001
- attack.t1083
- attack.t1027
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_ELZOB_T3_ATTRIBUTION {
    meta:
        description = "Tier 3 Attribution Fingerprint: Heuristic detection for Elzob 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 = "elzob" 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. Disconnect the affected endpoint from LAN, WAN, and Wi-Fi immediately to halt encryption across shares.
2. Kill active ransomware processes via Windows Task Manager or elevated PowerShell commands.
3. Preserve forensic evidence including memory dumps and ransomware binaries for hash attribution.
4. Block delivery vectors, including malicious sender domains and external command hosts.
5. Restore encrypted files from air-gapped, immutable backup archives.

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 extortion demand; decryption keys are not guaranteed and payment funds illicit groups.
2. Do not reboot systems before securing volatile memory data.

References & External Analysis

• Microsoft Defender Threat Encyclopedia - Ransom:Win32/Elzob
• Trend Micro Threat Encyclopedia - Ransom_Elzob
• Kaspersky Threat Intelligence Portal - Trojan-Ransom.Win32.Elzob
• Search "elzob" on VirusTotal (External Analysis)
• Search "elzob" on Any.Run (Sandbox Sandbox)
• Search "elzob" on MalwareBazaar (Malware Samples)

Frequently Asked Questions

Related Threats (Category: Ransomware)

Explore other documented threats in the same operational category:

• Winspeedup
• Windapp
• Emelent
• Selcry
• Hlubea
• Agentus
• Darkside
• Amtgimon

Machine-readable

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