Scarab

Overview

Ransomware:Win32/Scarab is a highly destructive file-encrypting trojan (Ransomware) that emerged prominently in 2017, frequently distributed via the massive Necurs botnet. It utilizes strong cryptography to lock user files, appending a distinctive extension (like `.scarab` or `.suicide`), and extorts cryptocurrency for the decryption key.

Understanding Scarab Ransomware
To the victim, a Scarab infection is an immediate crisis. Their desktop wallpaper is changed, files become inaccessible, and a ransom note (often named `HOW TO RECOVER ENCRYPTED FILES.TXT`) appears in every affected folder. For incident responders, Scarab is a severe threat. It often leverages the widespread reach of major botnets (like Necurs) for distribution via massive malspam campaigns, meaning an infection can spread rapidly across an organization if email defenses are breached.

Execution and Evasion Strategies
Scarab is primarily delivered via phishing emails containing malicious attachments (often ZIP files containing VBS or JavaScript downloaders). Upon execution, the payload deletes Volume Shadow Copies (`vssadmin.exe Delete Shadows /All /Quiet`) to prevent easy recovery (`T1490`). It then iterates through all local drives and accessible network shares, encrypting documents, databases, and media files. Unlike some ransomware that generates keys locally, Scarab often connects to a Command and Control (C2) server to obtain the public encryption key, allowing the attacker to maintain strict control over the decryption process.

Indicators of Compromise & Impact
The impact is immediate, catastrophic data loss and severe business interruption. EDR platforms will trigger heavily on the rapid, high-volume file modification events (`T1486`) and the execution of `vssadmin.exe`. Network logs may show HTTP POST requests to the attacker's C2 infrastructure immediately preceding the encryption phase. The presence of the `.scarab` file extensions is the definitive IoC.

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:

• T1059.003: Restrict execution of Windows Command Shell (cmd.exe) and block unauthorized batch scripts.
• T1105: Implement network intrusion detection systems (NIDS) and host-based firewalls to block unauthorized inbound or outbound file transfers.
• 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_SCARAB {
    meta:
        description = "Detects Scarab (ransomware)"
        author = "SystemHelpdesk Boilerplate Generator"
        date = "2026-07-06"
    strings:
        $s1 = "scarab" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

Sigma Rule

title: Suspicious Scarab Activity
id: 515c5c5321575ae424efde4214ccf08e
status: experimental
description: Detects generic indicators of the scarab malware family.
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith:
            - '\cmd.exe'
            - '\powershell.exe'
        CommandLine|contains:
            - "*scarab*"
    condition: selection
level: medium

Containment & Response Steps

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

1. Instantly sever the infected endpoint from the network to halt the encryption process, specifically protecting mapped network shares and cloud syncing folders.
2. Do NOT reboot or power off the machine immediately; capture a live memory image. The encryption keys may still reside in RAM.
3. Identify the initial infection vector (likely a phishing email) and purge similar messages from the corporate email gateway.
4. Restore affected systems from offline, immutable backups that were not accessible to the network during the encryption phase.

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; there is no guarantee the attackers will provide a working decryptor, and paying funds criminal enterprises.
2. Avoid reconnecting the machine to the network until it has been completely wiped and rebuilt from a known-clean image.

References & External Analysis

• Search "scarab" on VirusTotal (External Analysis)

Frequently Asked Questions

Related Families (Category: ransomware)

Explore other malware families in the same category:

• Wmqarhe5P8Fbt
• Eqtonex
• Duduunion
• Genericrxft
• Saturn

Machine-readable

Get this profile as JSON: https://jordan123234-malware-families-explorer.static.hf.space/api/scarab.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.