Teslacrypt

Overview

TeslaCrypt is a notorious ransomware family first detected in February 2015 that achieved widespread prominence by specifically targeting video gamers—encrypting game saves, maps, player profiles, and user modifications for over 40 popular video games (including Call of Duty, World of Warcraft, Minecraft, Fallout, and League of Legends) alongside standard business documents. TeslaCrypt was primarily distributed through exploit kits (Angler, Nuclear, Sweet Orange) leveraging Adobe Flash Player zero-day vulnerabilities (CVE-2015-0311, CVE-2015-5119). In May 2016, TeslaCrypt concluded in one of the most remarkable events in cybercrime history: the ransomware operators abruptly announced they were shutting down their operations, posting an apology note on their Tor payment site ('Project closed. We are sorry!') and publicly publishing the master private encryption key. Security researchers at ESET and Cisco Talos immediately utilized the master key to create free universal decryption utilities, allowing every affected victim worldwide to restore their encrypted files without paying ransom.

Known aliases

Threat reports may refer to this family under multiple names:

• TeslaCrypt
• Trojan.TeslaCrypt
• Win32/TeslaCrypt
• Ransom.TeslaCrypt

Threat Actor Attribution

Attribution is probabilistic, not a science. Each link below states its confidence level and the evidence behind it.

• TeslaCrypt Cybercrime Authors / May 2016 Public Master Key Release High confidence
  Basis: Active cybercrime syndicate between February 2015 and May 2016. In May 2016, the operators voluntarily closed the project, issued a public apology, and released the master private key used by ESET to decrypt all victims globally. [source]

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: Teslacrypt V1.0 · Teslacrypt V2.0 (.Vvv, .Ccc, .Abc) · Teslacrypt V3.0 (.Micro, .Mp3) · Teslacrypt V4.0 (Master Key Release)

MITRE ATT&CK Techniques

Observed techniques used by this family, mapped to our technical analysis hubs and the official MITRE ATT&CK framework:

MITRE D3FEND™ Defensive Countermeasures

Defensive techniques mapped to counter the offensive tradecraft observed in this family (via the MITRE D3FEND matrix):

Exploited Vulnerabilities (CVEs)

This malware family is documented weaponizing the following common vulnerabilities and exposures:

• CVE-2015-0311 — In-depth exploitation analysis and catalog intelligence (NIST NVD ↗).
• CVE-2015-5119 — In-depth exploitation analysis and catalog intelligence (NIST NVD ↗).

Command & Control (C2) and Network Profile

How this family talks to its operators. C2 traffic can often identify a family even when its code and configuration are hard to analyse. Ports and patterns are historical and change between campaigns, so use them as hunting leads rather than block-only rules.

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.

• 0ba91fcf3b2a3dbe16999be3a6c4b2de0a34fe9a42f36d8f5b40cf392bc6914c
• 4de40ad749e7b2eb26d2466f10c66be91a134372a6b2cbdf7de0d6cfcf52240b

Delivery vectors

• Angler, Nuclear, and Sweet Orange exploit kits exploiting Adobe Flash Player vulnerabilities (CVE-2015-0311, CVE-2015-5119)
• Phishing emails with malicious zip archives containing JavaScript droppers

Persistence mechanisms

• Deletion of Windows Volume Shadow Copies using vssadmin.exe
• HKCU\Software\Microsoft\Windows\CurrentVersion\Run autorun key creation

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:

rule MALWARE_WIN_TESLACRYPT_T1_ARTIFACT {
    meta:
        description = "Tier 1 Primitive Artifact: Raw string matches for Teslacrypt"
        tier = "T1 - Primitive Artifact"
        confidence = "Low-Medium (Fast Triage)"
        author = "SystemHelpdesk Threat Research Desk"
        date = "2026-10-14"
    strings:
        $s1 = "teslacrypt" ascii wide nocase
        $s2 = "teslacrypt" ascii wide nocase
        $s3 = "trojan.teslacrypt" ascii wide nocase
        $s4 = "win32/teslacrypt" ascii wide nocase
        $s5 = "ransom.teslacrypt" ascii wide nocase
    condition:
        uint16(0) == 0x5a4d and any of them
}

title: SystemHelpDesk Detection - Teslacrypt (Ransomware) Execution & Triage
id: a58e7405-890e-5b67-9b7d-1015c1a6ea0b
status: production
description: Detects execution, defense evasion, and persistence behaviors associated
  with the Teslacrypt 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/teslacrypt
- 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.t1071_001
- attack.t1566_001
- attack.t1547_001
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

rule MALWARE_WIN_TESLACRYPT_T3_ATTRIBUTION {
    meta:
        description = "Tier 3 Attribution Fingerprint: Heuristic detection for Teslacrypt 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 = "teslacrypt" 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
}

Containment & Response Steps

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

1. If encountering a legacy TeslaCrypt infection, DO NOT format the drive. The universal master decryption key is publicly available, and tools exist (e.g., from ESET or McAfee) to recover 100% of the files for free.
2. Isolate the endpoint to prevent any potential lateral movement, although TeslaCrypt primarily focused on local and mapped drive encryption.
3. Run the free TeslaCrypt decryption tool to restore the encrypted files.
4. Use an enterprise antivirus solution to scan for and remove the dormant TeslaCrypt executable and its associated registry persistence mechanisms.

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 under any circumstances; the operation is defunct, the infrastructure is offline, and a free decryptor exists.
2. Avoid deleting the encrypted files in a panic; they are fully recoverable using the public master key.

References & External Analysis

• ESET - Releases Decryptor for TeslaCrypt Ransomware
• Cisco Talos - Threat Spotlight: TeslaCrypt Master Key Released
• MITRE ATT&CK - TeslaCrypt
• Search "teslacrypt" on VirusTotal (External Analysis)
• Search "teslacrypt" on Any.Run (Sandbox Sandbox)
• Search "teslacrypt" on MalwareBazaar (Malware Samples)

Frequently Asked Questions

Related Threats (Category: Ransomware)

Explore other documented threats in the same operational category:

• Spynomore
• Nussamoc
• Petun
• Genericrxch
• Cyfin
• Syscon
• Banz
• Netshrink

Machine-readable

Get this profile as JSON: https://malware-families-catalog.systemhelpdesk.com/api/teslacrypt.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.