Sage
Table of Contents
Overview
Ransomware:Win32/Sage (specifically known as Sage 2.0) is a highly destructive crypto-ransomware family that gained significant notoriety in early 2017. A variant of the notorious CryLocker family, Sage is designed to systematically encrypt the victim's data and demand a ransom in Bitcoin, heavily utilizing the Tor network to anonymize its payment infrastructure and communications.
Understanding Sage (Ransomware)
To an end-user, a Sage infection is a nightmare scenario. Their desktop wallpaper is changed to a threatening ransom note, and all personal and business files are appended with the `.sage` extension, rendering them completely inaccessible. For an Incident Response team, Sage represents a critical failure in initial defenses, requiring immediate containment to prevent lateral movement across network shares (`T1083`).
Execution and Encryption Mechanics
Sage is primarily distributed via massive, localized malspam campaigns (`T1566.001`), often using weaponized Word documents with malicious macros, or disguised within ZIP archives. Upon execution, it disables Windows Automatic Repair (`T1490`) and deletes all Volume Shadow Copies (`vssadmin.exe Delete Shadows /All /Quiet`) to prevent easy data recovery. It then initiates a rapid encryption routine (`T1486`), using strong cryptography (often ChaCha20 and RSA) to lock files. Crucially, Sage uses Tor (`T1090.003`) to communicate with its C2 servers, passing the victim's unique ID and receiving the public encryption key, ensuring the attacker's infrastructure remains hidden.
Indicators of Compromise & Impact
The impact is catastrophic data loss. Host-based IoCs are glaringly obvious: mass file modifications, the presence of files ending in `.sage`, and the appearance of ransom notes like `!Recovery_[random_string].html`. EDR telemetry will show the execution of `vssadmin.exe` and `bcdedit.exe`. Network IoCs will reveal the compromised endpoint attempting to resolve `.onion` addresses or connecting to known Tor exit nodes.
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 (Ransomware) | Impact | ATT&CK ↗ |
T1490 | Inhibit System Recovery (Deleting Volume Shadow Copies) | Impact | ATT&CK ↗ |
T1090.003 | Proxy: Multi-hop Proxy (Tor Network for C2) | Command and Control | ATT&CK ↗ |
T1566.001 | Phishing: Spearphishing Attachment | Initial Access | 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-OAA | Outbound Network Traffic Filtering | Isolate | T1090.003 | Restrict outbound connections to known external proxy relays and enforce enterprise forward proxy authentication. |
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_SAGE_T1_ARTIFACT {
meta:
description = "Tier 1 Primitive Artifact: Raw string matches for Sage"
tier = "T1 - Primitive Artifact"
confidence = "Low-Medium (Fast Triage)"
author = "SystemHelpdesk Threat Research Desk"
date = "2026-10-14"
strings:
$s1 = "sage" 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 - Sage (Ransomware) Execution & Triage
id: 4a1b7a57-99d1-5b31-8fe4-5be5ee8f8e82
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
with the Sage 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/sage
- 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.t1090_003
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_SAGE_T3_ATTRIBUTION {
meta:
description = "Tier 3 Attribution Fingerprint: Heuristic detection for Sage 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 = "sage" 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 the infected endpoint's network connection (unplug ethernet, disable Wi-Fi) to stop Sage from encrypting connected network drives.
- Do not reboot the machine if encryption is actively in progress, as the decryption keys may temporarily reside in memory.
- Identify and secure all unaffected backups immediately to ensure they are not compromised by lateral movement.
- Format the infected drive and rebuild the system from a clean, trusted image.
What to Avoid
Common mistakes during response to this family that can destroy evidence, spread the infection, or worsen recovery.
- Do not pay the ransom. Paying provides no guarantee of data recovery and funds further cybercriminal operations.
- Avoid connecting external drives to the infected machine for forensics until it is completely isolated, as the ransomware will encrypt them instantly.
References & External Analysis
- Search "sage" on VirusTotal (External Analysis)
- Search "sage" on Any.Run (Sandbox Sandbox)
- Search "sage" on MalwareBazaar (Malware Samples)
Frequently Asked Questions
What is Sage and what threat category does it belong to?
Sage is classified as a Ransomware. Documented across security telemetry, it is engineered to execute unauthorized operations, establish persistent footholds on target endpoints, and facilitate malicious campaigns targeting enterprise and individual environments.
How does Sage establish persistence and evade defensive controls?
Sage typically establishes persistence through registry run keys, scheduled tasks, or service installations, while evading signature-based antivirus solutions through code obfuscation, memory injection, or anti-analysis sandbox checks.
What are the essential incident response steps for mitigating a Sage compromise?
Security teams responding to Sage should immediately isolate affected endpoints from the network, perform memory triage to capture volatile forensic artifacts, audit registry and startup persistence mechanisms, revoke exposed user credentials, and restore systems from verified, clean backups.
What cryptographic algorithms and file targeting techniques does Sage employ during execution?
Sage typically leverages hybrid cryptographic architectures combining symmetric stream or block ciphers (such as AES-256 or ChaCha20) for rapid file encryption with asymmetric algorithms (such as RSA-2048 or Curve25519) to securely protect the session keys. It aggressively targets sensitive file extensions including corporate documents, databases, virtual disks, and backups while systematically executing commands to delete Volume Shadow Copies (vssadmin delete shadows /all /quiet) and disable system recovery options.
Are decryptors available for Sage, and what is the recommended recovery procedure?
Decryption availability for Sage depends on whether security researchers or law enforcement (such as the No More Ransom initiative) have recovered the master private keys or discovered flaws in its key generation routines. Victims should never pay the extortion demand, as payment fuels criminal operations without guaranteeing file restoration. The recommended recovery procedure entails isolating infected hosts, conducting forensic disk imaging, identifying the root access vector, and restoring validated systems from immutable offline backups.
How do I remove the Sage Ransomware from Windows?
Manual removal of Sage 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 Sage a virus or a Ransomware?
Sage is classified as a Ransomware. Unlike traditional viruses that infect files, modern malware like Sage typically operates as a standalone payload designed to compromise systems, steal data, or deploy secondary stage implants.
What are the main symptoms of a Sage infection?
Symptoms of Sage 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 Sage 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/sage.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.