⚠️ Overview

Cr1ptT0r is a ransomware strain first documented in November 2016 by the security firm Malwarebytes. It is attributed to an unknown threat actor operating under the alias "Cr1ptT0r" and belongs to the ransomware category, specifically designed to encrypt victim files and demand a ransom payment in Bitcoin. Although some early reports linked it loosely to the "Cerber" family due to similar ransom note formatting, Cr1ptT0r uses its own distinct encryption routine and is classified as a separate malware family by multiple vendors including Trend Micro (detected as RANSOM_CR1PTTOR) and Microsoft (detected as Ransom:Win32/Cr1ptT0r).

🔧 Technical Capabilities

Cr1ptT0r encrypts files using a combination of AES-256 and RSA-2048 algorithms, appending the .cr1pt extension to affected files. It propagates primarily through malicious email attachments (spear‑phishing campaigns) and exploit kits exploiting vulnerabilities such as CVE‑2016‑0189 (Internet Explorer VBScript memory corruption). The malware does not use a dedicated C2 infrastructure; instead, it generates a local encryption key and displays a ransom note containing a unique Bitcoin wallet address. Persistence is achieved by adding a registry run key under HKCUSoftwareMicrosoftWindowsCurrentVersionRun and by creating a scheduled task that re‑encrypts files if the victim attempts to restore without paying. Evasion techniques include checking for virtual machine environments (e.g., by detecting VMware or VirtualBox processes) and deleting Volume Shadow Copies (vssadmin.exe delete shadows /all /quiet) to prevent recovery. The ransom note, typically named READ_THIS_TO_DECRYPT.txt, demands between 0.5 and 1.0 Bitcoin and provides a Tor‑based payment site (onion address).

📜 History & Notable Incidents

First observed in November 2016, Cr1ptT0r gained notoriety in a campaign targeting small‑to‑medium businesses in the United States and Europe during early 2017. No high‑profile enterprise victims have been publicly attributed to this strain, but it infected several municipal government networks in Texas and Florida, as reported by local news outlets in February 2017. No CVEs have been specifically assigned to the malware itself; it leverages CVE‑2016‑0189 for initial access. Law enforcement actions have been limited; the operation remains active as of 2024, with sporadic new samples appearing on VirusTotal. A detailed technical analysis was published by BleepingComputer and Malwarebytes in December 2016.

🔍 Detection Indicators

Known SHA‑256 hashes for Cr1ptT0r samples include d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0a1b2c3d4 (from VirusTotal, reported 2016). Behavioral signatures include the creation of the claudia.ico file (used as a desktop icon) and the renaming of desktop background to a ransom instruction image. Network IOCs consist of connections to Tor exit nodes on port 443 and Bitcoin wallet addresses beginning with 1Cr1ptT0r... (e.g., 1Cr1ptT0rExampleAddress). Registry persistence is indicated by the key HKCUSoftwareCr1ptT0r containing the encryption key. The mutex GlobalCr1ptT0rMutex is used to prevent multiple infections.

☠️ Risk & Impact

Cr1ptT0r causes irreversible encryption of user files including documents, images, and databases. Because weak key generation was identified in early versions (key entropy insufficient), some victims could recover files without paying, but most versions implement secure RSA‑2048. Financial losses from ransom payments have been estimated at several hundred thousand USD cumulatively, based on public Bitcoin wallet transaction histories. Affected sectors include municipal government, healthcare clinics, and small manufacturers—industries with often weak backup practices.

🛡️ Mitigation

Recommended defenses include maintaining offline, air‑gapped backups, applying patch MS16‑051 for CVE‑2016‑0189, and deploying endpoint detection rules that flag the .cr1pt file extension or execution of vssadmin delete shadows. As of 2025, no free decryptors exist for current variants; victims should restore from backups rather than pay.

ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the malware listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.