Blamon
Table of Contents
Overview
Blamon (tracked across endpoint security telemetry under signatures Ransom:Win32/Blamon, Ransom:Win32/Blamon.A, and Trojan-Ransom.Win32.Blamon) is a destructive crypto-ransomware family designed to lock local and network-attached storage on Windows systems. Infiltrating environments primarily through malicious email campaigns featuring weaponized macros or archive files, Blamon initiates execution by verifying administrative privileges and conducting host discovery. It terminates database management engines, mail servers, and backup utilities to release file access locks. Blamon encrypts user documents, databases, archives, and multimedia files using AES-256 encryption wrapped with an embedded RSA public key, appending a distinctive extension such as .blamon to encrypted files. It executes vssadmin delete shadows /all /quiet and wbadmin delete catalog -quiet to destroy Volume Shadow Copies and system state backups, before dropping extortion notes demanding cryptocurrency payment for file restoration.
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 |
|---|---|---|---|
T1486 | Data Encrypted for Impact | Impact | ATT&CK ↗ |
T1490 | Inhibit System Recovery | Impact | ATT&CK ↗ |
T1566.001 | Phishing: Spearphishing Attachment | Initial Access | ATT&CK ↗ |
T1083 | File and Directory Discovery | Discovery | ATT&CK ↗ |
T1070.004 | Indicator Removal: File Deletion | Defense Evasion | ATT&CK ↗ |
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):
| D3FEND ID | Countermeasure Name | Tactic | Countered ATT&CK | Defensive Guidance |
|---|---|---|---|---|
D3-FDA | File Directory Access Auditing | Detect | T1083 | Audit and alert on high-frequency recursive directory queries executed by non-system and unclassified binaries. |
D3-FAED | File Alteration Early Detection | Detect | T1486 | Deploy canary files and monitor mass rename/encryption I/O spikes to terminate ransomware threads immediately. |
D3-VSS | Volume Shadow & Snapshot Hardening | Harden | T1490 | Block execution of vssadmin.exe and wmic shadowcopy delete; maintain air-gapped immutable backup repositories. |
D3-FS | File Sandboxing (Attachment Detonation) | Isolate | T1566.001 | Detonate macro-enabled documents, ISOs, and password-protected archives inside an isolated hypervisor. |
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_BLAMON_T1_ARTIFACT {
meta:
description = "Tier 1 Primitive Artifact: Raw string matches for Blamon"
tier = "T1 - Primitive Artifact"
confidence = "Low-Medium (Fast Triage)"
author = "SystemHelpdesk Threat Research Desk"
date = "2026-10-14"
strings:
$s1 = "blamon" ascii wide nocase
$s2 = "ransom:win32/blamon" ascii wide nocase
$s3 = "ransom:win32/blamon.a" ascii wide nocase
$s4 = "trojan-ransom.win32.blamon" ascii wide nocase
$s5 = "win32/blamon" ascii wide nocase
$s6 = "ransom.blamon" 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 - Blamon (Ransomware) Execution & Triage
id: 72796745-0bea-5fee-a773-2dcbedda4f22
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
with the Blamon 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/blamon
- 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.t1070_004
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_BLAMON_T3_ATTRIBUTION {
meta:
description = "Tier 3 Attribution Fingerprint: Heuristic detection for Blamon 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 = "blamon" 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 sever network and Wi-Fi connections to prevent ransomware spread to network shares.
- Terminate active encryption processes using Windows Task Manager or command-line tools.
- Identify and block malicious sender email addresses and payload delivery domains.
- Capture memory forensics and file samples for incident response and threat intelligence telemetry.
- Reimage compromised endpoints and restore business data from validated, immutable backups.
What to Avoid
Common mistakes during response to this family that can destroy evidence, spread the infection, or worsen recovery.
- Do not pay the cryptocurrency extortion fee, as it does not guarantee key delivery and finances further attacks.
- Do not reboot affected systems before capturing volatile forensic memory artifacts.
References & External Analysis
- Microsoft Defender Threat Encyclopedia - Ransom:Win32/Blamon
- Trend Micro Threat Encyclopedia - Ransom_Blamon
- Kaspersky Threat Intelligence Portal - Trojan-Ransom.Win32.Blamon
- Search "blamon" on VirusTotal (External Analysis)
- Search "blamon" on Any.Run (Sandbox Sandbox)
- Search "blamon" on MalwareBazaar (Malware Samples)
Frequently Asked Questions
What is Ransom:Win32/Blamon?
Blamon is a crypto-ransomware family targeting Windows devices, encrypting user and enterprise files with AES-256 and demanding cryptocurrency ransom.
How does Blamon inhibit system recovery options?
It executes vssadmin commands to silently delete all Volume Shadow Copies and uses wbadmin to invalidate backup catalogs.
What file types are encrypted by Blamon?
It targets office documents, spreadsheets, databases, system backups, source code files, and virtual machine images.
How is Blamon ransomware distributed?
It is distributed through phishing email attachments containing weaponized macros, malicious downloaders, and exploit kits.
How should an enterprise respond to a Blamon ransomware infection?
Isolate the compromised system immediately, capture volatile memory artifacts, remove malicious binaries, and restore data from offline backups.
What are the main symptoms of a Blamon infection?
Symptoms of Blamon 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 Blamon 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/blamon.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.