Chimera

Category: ransomware · Aliases: Ransomware.Chimera, Trojan-Ransom.Win32.Chimera, Extortion.Chimera · Sample count (EMBER 2018): 1 · Enrichment: insufficient_information · Updated: 2026-07-02T07:43:55Z

Category: RansomwareActor: Unknown / CybercriminalIndustry: Global / OpportunisticMotivation: Opportunistic

Overview

Executive Summary

Chimera is a highly aggressive strain of enterprise ransomware that pioneered the "double extortion" tactic. It not only encrypts the victim's critical data, halting business operations, but it also actively exfiltrates sensitive files to attacker-controlled servers before encryption begins. The threat actors then threaten to publish this confidential data (intellectual property, customer records, financial data) on public "leak sites" if the ransom is not paid, significantly increasing the pressure on the victim organization.

Infection Vector and Technical Capabilities

Chimera typically infiltrates networks via highly targeted spear-phishing campaigns delivering malicious payloads (often utilizing exploits like those found in the Angler Exploit Kit) or by brute-forcing weakly secured Remote Desktop Protocol (RDP) servers. Once inside the network, it executes a devastating two-pronged attack:

Data Exfiltration (The First Extortion): Before encrypting anything, Chimera maps the network and silently uploads high-value files to external cloud storage or FTP servers controlled by the attackers.
Rapid Encryption (The Second Extortion): It utilizes strong cryptography (AES+RSA) to encrypt user files and network shares, appending a `.crypt` extension. It actively deletes Volume Shadow Copies (`vssadmin.exe Delete Shadows`) to prevent easy data restoration.
Psychological Pressure: The ransom note explicitly states that data has been stolen and will be published if the cryptocurrency demand is not met, creating a severe GDPR/compliance crisis alongside the operational outage.

Threat Assessment

A Chimera infection is a catastrophic security and public relations incident. It poses an existential threat to the organization through severe data loss, extended downtime, guaranteed regulatory fines (due to the data breach aspect), and immense reputational damage.

Incident Response and Remediation

Immediate Network Segmentation: Instantly sever the network connection of all infected machines to halt the lateral movement and, crucially, stop any ongoing data exfiltration.
Data Breach Protocol: Because Chimera exfiltrates data, this incident must be immediately treated as a major data breach. Engage legal counsel and prepare for mandatory regulatory disclosures (e.g., GDPR, CCPA). Do not attempt to negotiate without professional IR guidance.
Eradication and Recovery: Eradicating ransomware requires a complete infrastructure rebuild. All affected machines must be wiped to bare metal and rebuilt from known-good, offline backups. All enterprise credentials must be rotated globally.

Known aliases

Threat reports may refer to this family under multiple names:

MITRE ATT&CK Techniques

This family has been observed using the following ATT&CK techniques: T1486 T1048 T1490

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_CHIMERA {
    meta:
        description = "Detects Chimera (ransomware)"
        author = "SystemHelpdesk Boilerplate Generator"
        date = "2026-07-06"
    strings:
        $s1 = "chimera" ascii wide nocase
        $s2 = "ransomware.chimera" ascii wide nocase
        $s3 = "trojan-ransom.win32.chimera" ascii wide nocase
        $s4 = "extortion.chimera" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

Sigma Rule

title: Suspicious Chimera Activity
id: f0542eda41af8850ded8e48750cfdc4e
status: experimental
description: Detects generic indicators of the chimera malware family.
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith:
            - '\cmd.exe'
            - '\powershell.exe'
        CommandLine|contains:
            - "*chimera*"
            - "*ransomware.chimera*"
            - "*trojan-ransom.win32.chimera*"
            - "*extortion.chimera*"
    condition: selection
level: medium

References & External Analysis

Search "chimera" on VirusTotal (External Analysis)

Frequently Asked Questions

How do I remove the Chimera Ransomware from Windows?

Manual removal of Chimera 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 Chimera a virus or a Ransomware?

Chimera is classified as a Ransomware. Unlike traditional viruses that infect files, modern malware like Chimera typically operates as a standalone payload designed to compromise systems, steal data, or deploy secondary stage implants.

What are the main symptoms of a Chimera infection?

Symptoms of Chimera 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.

Related Families (Category: ransomware)

Explore other malware families in the same category:

Protect Your Network Against Ransomwares

Want to prevent Chimera and similar threats from compromising your organization? Read our comprehensive defensive guide: Ransomware Protection Guide.

Need help with an active incident? Published by the SystemHelpdesk team.

Machine-readable

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