Sage

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 the 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.

Generated Detections (Boilerplate)

These YARA and Sigma rules are auto-generated based on the family name and aliases. They must be heavily tuned before deployment in a production environment.

YARA Rule

rule MALWARE_WIN_SAGE {
    meta:
        description = "Detects Sage (ransomware)"
        author = "SystemHelpdesk Boilerplate Generator"
        date = "2026-07-06"
    strings:
        $s1 = "sage" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

Sigma Rule

title: Suspicious Sage Activity
id: 6aab9eb8f32e566dfa41cbd48f53c80d
status: experimental
description: Detects generic indicators of the sage malware family.
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith:
            - '\cmd.exe'
            - '\powershell.exe'
        CommandLine|contains:
            - "*sage*"
    condition: selection
level: medium

Containment & Response Steps

Ordered checklist for responders. Adapt to your environment and engage professional support for active incidents.

1. Immediately sever the infected endpoint's network connection (unplug ethernet, disable Wi-Fi) to stop Sage from encrypting connected network drives.
2. Do not reboot the machine if encryption is actively in progress, as the decryption keys may temporarily reside in memory.
3. Identify and secure all unaffected backups immediately to ensure they are not compromised by lateral movement.
4. 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.

1. Do not pay the ransom. Paying provides no guarantee of data recovery and funds further cybercriminal operations.
2. 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)

Frequently Asked Questions

Related Families (Category: ransomware)

Explore other malware families in the same category:

• 0Y1A48Lx2Yib
• Tweakbitdu
• Rogan
• Nosok
• Avkiller

Machine-readable

Get this profile as JSON: https://jordanricky1604-ship-it.github.io/malware-families-catalog/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.