Egregor Malware: Full Overview

Published: 12/12/2025

Written by: Lizzie Danielson

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What is Egregor Malware?

Egregor belongs to a class of ransomware known for encrypting files and demanding payment for retrieval. It is often associated with “ransomware-as-a-service” (RaaS), which allows threat actors to license its malicious capabilities. Notably, it uses advanced evasion techniques and has aliases like “Massive” in certain threat intelligence databases. Its threat level is particularly high due to its global reach and ability to cripple organizations within hours.

When was Egregor first discovered?

Egregor was first spotted in September 2020 and was identified by multiple security researchers soon after. It was linked to several high-profile attacks on firms across various industries, cementing its place as one of the most notorious ransomware threats of its time.

Who created Egregor?

The specific group behind Egregor remains unconfirmed. However, it is believed to be linked to actors previously associated with the Sekhmet ransomware. The structure of Egregor’s operations suggests collaboration between skilled developers and affiliate threat actors.

What does Egregor target?

Egregor targets a range of industries, including healthcare, transportation, and retail. Its ability to exploit vulnerabilities in corporate networks makes it especially dangerous to mid-sized and large organizations. Geographically, its attacks have been noted across North America, Europe, and parts of Asia.

Egregor distribution method

The primary infection vectors for Egregor include phishing emails with malicious attachments, exploitation of remote desktop protocol (RDP) weaknesses, and the use of compromised software. Once inside a network, it spreads rapidly using pre-installed administrative tools.

Technical analysis of Egregor malware

Egregor’s behavior involves multiple stages:

  • Initial Access: Exploits weaknesses like unpatched software or phishing.

  • Payload Delivery: Encrypts files using strong algorithms and displays ransom notes.

  • Data Exfiltration: Threatens to publish stolen data if ransom demands are not met.

  • Evasion: Uses obfuscation and anti-debugging techniques to avoid detection.

Tactics, Techniques & Procedures (TTPs)

Egregor aligns with MITRE ATT&CK techniques, such as:

  • T1566 (Phishing)

  • T1078 (Valid Accounts)

  • T1053 (Scheduled Task/Job)

Indicators of Compromise (IoCs)

  • IPs associated with command-and-control servers.

  • Known hashes of malicious executables.

  • Abnormal outbound traffic activity.

How to know if you’re infected with Egregor?

Signs of infection include encrypted files with unusual extensions, slow system performance, unexpected ransom notes, and suspicious network activity.

Egregor removal instructions

Manual removal can be risky due to its complexity. It’s recommended to:

  • Isolate infected devices immediately.

  • Seek professional remediation tools like those provided by Huntress.

  • Avoid paying the ransom to discourage further attacks.

Is Egregor still active?

Although Egregor’s activity has declined since late 2021, variants and residual threats persist. Keeping systems updated with the latest security measures is vital.

Mitigation & prevention strategies

Preventing Egregor involves:

  • Implementing multifactor authentication (MFA).

  • Continuous network monitoring.

  • Ensuring software patches and updates.

  • Educating employees on cyber hygiene.

  • Leveraging Huntress’ 24/7 threat detection and response services to identify issues before they escalate.

Related educational articles & videos

FAQ

Egregor is a type of ransomware designed to encrypt sensitive files and extort organizations through double extortion tactics. Once it infiltrates a system, it encrypts data and threatens to leak it unless a ransom is paid.

Egregor typically spreads through phishing emails, weak RDP configurations, or exploited software vulnerabilities. Threat actors use these methods to gain unauthorized access to networks and deploy the malware.

While reports of Egregor’s activity have decreased, its lineage and variants still pose risks. Evolving strains and similar attack methodologies make ongoing vigilance necessary for organizations.

To protect against Egregor, organizations should adopt robust security practices such as enabling MFA, training employees to recognize phishing attempts, keeping software updated, and utilizing advanced threat detection solutions like Huntress.

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