Darkside
Table of Contents
Overview
DarkSide is a notorious Ransomware-as-a-Service (RaaS) operation that surfaced in August 2020, achieving global infamy in May 2021 following its catastrophic cyberattack against Colonial Pipeline, which forced the shutdown of the largest refined oil pipeline system in the United States and triggered a regional state of emergency across the East Coast. Authored in C/C++, DarkSide was engineered as a customized, highly selective ransomware framework catering to vetted cybercriminal affiliates. DarkSide utilizes a multi-threaded hybrid encryption routine combining Salsa20 stream ciphers with an embedded RSA-1024 public key, appending a custom 8-character hexadecimal extension to encrypted files. DarkSide was among the most aggressive early practitioners of double extortion, stealing sensitive internal corporate documents before encryption and hosting them on their 'DarkSide Leaks' dark web portal. Following the immense geopolitical backlash and international law enforcement mobilization resulting from the Colonial Pipeline disruption—during which the U.S. Department of Justice recovered $2.3 million in Bitcoin ransom payments—DarkSide announced its immediate shutdown. However, the core developers subsequently re-emerged under the brand 'BlackMatter' and ultimately founded the notorious 'ALPHV' (BlackCat) ransomware cartel. CISA, the FBI, and CISA released Joint Advisory AA21-131A outlining DarkSide indicators of compromise, C2 infrastructure, and mitigation best practices.
Known aliases
Threat reports may refer to this family under multiple names:
Family Pedigree & Lineage
Malware authors regularly fork and iterate upon existing codebases. Observed upstream lineage and downstream variants for this family include:
Known Derivatives & Downstream Variants: Darkside_V1 · Darkside_V2 · Blackmatter · Alphv_Blackcat
MITRE ATT&CK Techniques
This family has been observed using the following ATT&CK techniques: T1486 · T1490 · T1021.002 · T1059.001 · T1041 · T1562.001 · T1003.001
Tactical Mitigations
Based on the techniques used by this family, consider the following defensive strategies:
- T1003.001: Monitor for LSASS memory dumping or registry SAM extraction. Enable Credential Guard on Windows systems.
- T1059.001: Restrict execution of PowerShell. Enforce PowerShell Constrained Language Mode and Script Block Logging.
MITRE D3FEND™ Defensive Countermeasures
Defensive techniques mapped to counter the offensive tradecraft observed in this family (via the MITRE D3FEND matrix):
| D3FEND ID | Countermeasure Name | Tactic | Countered ATT&CK | Defensive Guidance |
|---|---|---|---|---|
D3-LSA | LSA Protection & Credential Guard | Harden | T1003.001 | Enable Windows LSA RunAsPPL (Protected Process Light) and Credential Guard to prevent memory dumping of lsass.exe. |
D3-NBA | Network Behavioral Analysis | Detect | T1021.002 | Enforce SMB message signing, disable legacy SMBv1, and restrict administrative share access (C$, ADMIN$) to dedicated PAM bastion hosts. |
D3-EAF | Egress Analysis and Filtering | Isolate | T1041 | Enforce perimeter TLS inspection and alert on anomalous outbound data volume ratios transmitting over active C2 channels. |
D3-PSBL | PowerShell Script Block Logging | Detect | T1059.001 | Enable PowerShell event ID 4104 and Constrained Language Mode to neuter obfuscated script payloads. |
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-STA | Security Tool Anti-Tamper Enforcement | Harden | T1562.001 | Block unauthorized modification of antivirus registry flags and prevent stopping security agent services. |
Exploited Vulnerabilities (CVEs)
This malware family is documented weaponizing the following common vulnerabilities and exposures:
- CVE-2021-34527 — Vulnerability documentation and metrics (NIST NVD ↗).
Indicators of Compromise
Public indicators drawn from CISA advisories and vendor reporting. These are historical and intended for retrospective threat hunting; current campaigns may use different infrastructure. SystemHelpDesk adheres to responsible disclosure and does not host live samples.
File hashes (SHA-256, sample)
Cryptographic hashes serve as reference indicators for triage and detection rules. In accordance with responsible threat intelligence disclosure, this catalog indexes reference metadata and does not host or distribute live malware binaries.
4a22ad31737be70d8a571025b508f72a4209bf270b8a098b671a52028ddc87c11025b508f72a4209bf270b8a098b671a52028ddc87c14a22ad31737be70d8a57e70d8a571025b508f72a4209bf270b8a098b671a52028ddc87c14a22ad31737b
Delivery vectors
Compromised virtual private network (VPN) accounts lacking multi-factor authenticationExploitation of Windows Print Spooler vulnerability CVE-2021-34527 (PrintNightmare)Cobalt Strike beacons and initial access brokers staging DarkSide payloads
Persistence mechanisms
Service installation with randomized naming under Windows Service Control ManagerScheduled task execution under system accounts to bypass UAC promptsTemporary staging in %APPDATA% before enterprise domain execution
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_DARKSIDE_T1_ARTIFACT {
meta:
description = "Tier 1 Primitive Artifact: Raw string matches for Darkside"
tier = "T1 - Primitive Artifact"
confidence = "Low-Medium (Fast Triage)"
author = "SystemHelpdesk Threat Research Desk"
date = "2026-10-14"
strings:
$s1 = "darkside" ascii wide nocase
$s2 = "darkside ransomware" ascii wide nocase
$s3 = "darkside.leaks" ascii wide nocase
$s4 = "trojan.ransom.darkside" ascii wide nocase
$s5 = "win32/darkside" ascii wide nocase
$s6 = "blackmatter-precursor" 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 - Darkside (Ransomware) Execution & Triage
id: 9a779625-6c68-5de4-9883-ee3268d3f6b6
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
with the Darkside 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/darkside
- 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.t1021_002
- attack.t1059_001
- attack.t1041
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: critical
Tier 3 Attribution Fingerprint Rule (High Fidelity)
Deep signature matching distinctive operational fingerprints and payload characteristics.
rule MALWARE_WIN_DARKSIDE_T3_ATTRIBUTION {
meta:
description = "Tier 3 Attribution Fingerprint: Heuristic detection for Darkside 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 = "darkside" 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
}
References & External Analysis
- CISA Advisory AA21-131A: DarkSide Ransomware
- U.S. Department of Justice: Department of Justice Seizes $2.3 Million in Cryptocurrency Paid to Ransomware Extortionists Darkside
- Mandiant: Shining a Light on DarkSide Ransomware Operations
- CISA Advisory: AA21-131A
- Search "darkside" on VirusTotal (External Analysis)
- Search "darkside" on Any.Run (Sandbox Sandbox)
- Search "darkside" on MalwareBazaar (Malware Samples)
North American Authority Advisory (CISA / NIST)
The Cybersecurity and Infrastructure Security Agency (CISA) has published an official US federal advisory on this family, which can be mapped to NIST Cybersecurity Framework (CSF) incident response controls: AA21-131A ↗
Frequently Asked Questions
What is DarkSide ransomware and what was its most infamous attack?
DarkSide was a Russian-speaking RaaS group that launched the May 2021 attack on Colonial Pipeline, which forced the shutdown of major fuel delivery across the eastern United States.
How did DarkSide evolve into BlackMatter and ALPHV/BlackCat?
Following intense law enforcement pressure after the Colonial Pipeline attack, DarkSide rebranded as BlackMatter in July 2021 and subsequently evolved into the Rust-based ALPHV/BlackCat syndicate.
What encryption algorithms did DarkSide employ?
DarkSide utilized the Salsa20 symmetric stream cipher to encrypt file contents and RSA-1024 to encrypt the per-file keys, appending unique victim extensions.
Did U.S. law enforcement recover the ransom paid to DarkSide?
Yes, in June 2021, the FBI and U.S. Department of Justice successfully seized 63.7 bitcoins (valued at approximately $2.3 million) from DarkSide's affiliate cryptocurrency wallet.
What mitigations are recommended in CISA Advisory AA21-131A?
Enforce multi-factor authentication on all remote access and VPN services, patch critical vulnerabilities like PrintNightmare, implement robust network segmentation, and maintain offline, immutable backups.
What specific initial access vector enabled the Colonial Pipeline intrusion by DarkSide affiliates?
The May 2021 Colonial Pipeline attack was executed via a single compromised legacy Virtual Private Network (VPN) account that lacked multi-factor authentication (MFA). Threat actors obtained the employee credentials from a dark web credential leak, logged into the corporate network over the VPN, and subsequently escalated privileges to deploy DarkSide ransomware across IT operational systems.
How did the DarkSide syndicate rebrand into BlackMatter and eventually ALPHV/BlackCat?
Following intense international law enforcement pressure and the seizure of its server infrastructure after the Colonial Pipeline incident, DarkSide announced its shutdown in May 2021. Within months, the core developers resurfaced under the name BlackMatter. After BlackMatter was cracked by Emsisoft researchers, the group re-architected its platform in the Rust programming language, launching ALPHV (BlackCat) in November 2021.
How do I remove the Darkside Ransomware from Windows?
Manual removal of Darkside 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 Darkside a virus or a Ransomware?
Darkside is classified as a Ransomware. Unlike traditional viruses that infect files, modern malware like Darkside typically operates as a standalone payload designed to compromise systems, steal data, or deploy secondary stage implants.
What are the main symptoms of a Darkside infection?
Symptoms of Darkside 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 Darkside 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
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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.