Imali
Table of Contents
Overview
Imali (tracked across antimalware signatures as Ransom:Win32/Imali, Trojan-Ransom.Win32.Imali, and Ransom.Imali) is a targeted Windows crypto-ransomware family designed for rapid local storage and network share encryption. Delivered via exploit kits, malicious software repacks, and brute-forced RDP accounts, Imali halts essential Windows database and backup services, deletes volume shadow copies with 'vssadmin delete shadows /all /quiet', and suppresses automatic recovery prompts via bcdedit. Imali encrypts target files using AES-256 in CBC mode, appending the '.imali' extension to encrypted files. It stores the encrypted session keys in each file header using an embedded RSA-2048 master public key, and generates ransom demand notes ('README_RESTORE_IMALI.txt') instructing victims to contact the threat operators.
Known aliases
Threat reports may refer to this family under multiple names:
Family Pedigree & Lineage
Malware authors regularly fork and iterate upon existing codebases. Observed upstream lineage and downstream variants for this family include:
Known Derivatives & Downstream Variants: Ransom:Win32/Imali.A · Ransom:Win32/Imali.B
MITRE ATT&CK Techniques
This family has been observed using the following ATT&CK techniques: T1486 · T1490 · T1489 · T1083 · T1027
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-BDA | Binary De-obfuscation & Unpacking | Analyze | T1027 | Utilize memory dump scanners and entropy inspection to unpack encrypted stagers during process creation. |
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-SPP | Service Protection Policies | Harden | T1489 | Configure strict DACLs on Windows Service Control Manager to prevent unauthorized termination of antivirus and backup services. |
D3-VSS | Volume Shadow & Snapshot Hardening | Harden | T1490 | Block execution of vssadmin.exe and wmic shadowcopy delete; maintain air-gapped immutable backup repositories. |
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_IMALI_T1_ARTIFACT {
meta:
description = "Tier 1 Primitive Artifact: Raw string matches for Imali"
tier = "T1 - Primitive Artifact"
confidence = "Low-Medium (Fast Triage)"
author = "SystemHelpdesk Threat Research Desk"
date = "2026-10-14"
strings:
$s1 = "imali" ascii wide nocase
$s2 = "ransom:win32/imali" ascii wide nocase
$s3 = "trojan-ransom.win32.imali" ascii wide nocase
$s4 = "win32/imali" ascii wide nocase
$s5 = "ransom.imali" ascii wide nocase
$s6 = "imali ransomware" 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 - Imali (Ransomware) Execution & Triage
id: 2244fd36-ee8d-5aa4-a896-ecc58e1df954
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
with the Imali 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/imali
- 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.t1489
- 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: criticalTier 3 Attribution Fingerprint Rule (High Fidelity)
Deep signature matching distinctive operational fingerprints and payload characteristics.
rule MALWARE_WIN_IMALI_T3_ATTRIBUTION {
meta:
description = "Tier 3 Attribution Fingerprint: Heuristic detection for Imali 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 = "imali" 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
}References & External Analysis
- Microsoft Defender Threat Encyclopedia - Ransom:Win32/Imali
- Trend Micro Threat Encyclopedia - Ransom.Win32.Imali
- Search "imali" on VirusTotal (External Analysis)
- Search "imali" on Any.Run (Sandbox Sandbox)
- Search "imali" on MalwareBazaar (Malware Samples)
Frequently Asked Questions
What is Ransom:Win32/Imali?
Imali is a targeted Windows crypto-ransomware family that encrypts files and network shares using AES-256 and RSA-2048.
How does Imali prevent shadow copy recovery?
It runs vssadmin delete shadows commands to erase volume shadow copies before starting encryption.
How is Imali delivered to victim systems?
It is delivered through malicious software downloads, exploit kits, and compromised remote access credentials.
Can files with the .imali extension be decrypted without paying?
No public decryption tool exists because Imali uses industry-standard AES-256 with asymmetric RSA key wrapping.
What defensive measures protect against Imali ransomware?
Enforce multi-factor authentication on remote access, maintain isolated backups, and monitor endpoints for shadow copy deletion.
How do I remove the Imali Ransomware from Windows?
Manual removal of Imali 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 Imali a virus or a Ransomware?
Imali is classified as a Ransomware. Unlike traditional viruses that infect files, modern malware like Imali typically operates as a standalone payload designed to compromise systems, steal data, or deploy secondary stage implants.
What are the main symptoms of a Imali infection?
Symptoms of Imali 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 Imali 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/imali.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.