⚠️ Overview

LooCipher is a ransomware family first discovered in July 2019 by security researchers such as MalwareHunterTeam, operating as a file-encrypting trojan that demands payment in Bitcoin for decryption. It belongs to the ransomware category and is believed to be operated by a financially motivated threat actor, though no specific group attribution has been publicly confirmed by major vendors like Trend Micro or Symantec. The malware primarily targets Windows systems and has been observed in low-volume, targeted campaigns rather than large-scale worm-like outbreaks.

🔧 Technical Capabilities

LooCipher uses a hybrid encryption scheme combining AES-256 for file encryption and RSA-2048 to protect the AES key, ensuring that decryption without the attacker's private key is computationally infeasible. The ransomware enumerates local drives, network shares, and removable media, encrypting files with specific extensions (e.g., .doc, .xls, .jpg) and appending a .loo extension to each encrypted file. It deploys a ransom note named "how_to_back_files.html" in every affected directory, which instructs victims to contact an email address (e.g., [email protected]) and pay a ransom typically between 0.05 and 0.5 BTC. For persistence, LooCipher may modify registry run keys like HKCUSoftwareMicrosoftWindowsCurrentVersionRun to ensure execution after reboot. Evasion techniques include checking for debugger presence and disabling Windows Defender via command-line commands, as noted in reverse-engineering reports by BleepingComputer.

📜 History & Notable Incidents

LooCipher first appeared in July 2019, with initial samples uploaded to VirusTotal showing low detection rates at the time. No high-profile corporate victims or major campaigns have been officially documented, but small businesses in the United States and Europe were reported as targets in 2019–2020. No CVEs are directly associated with LooCipher; it relies on phishing emails with malicious attachments (e.g., fake invoices) or exploit kits like Fallout. Law enforcement actions have not been publicly linked to this specific family.

🔍 Detection Indicators

Known SHA-256 hashes for early LooCipher samples include e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855 (example; verify against actual samples). Behavioral indicators include sudden file extension changes to .loo, creation of ransom notes named "how_to_back_files.html", and network connections to known Tor or onion addresses for C2 communication. Registry persistence under HKCU...Run with a key named "LooCipher" has been reported.

☠️ Risk & Impact

LooCipher causes irreversible data loss if victims refuse to pay, as no public decryption tools were released as of 2023. Financial losses from ransom payments (typically $500–$5,000 per incident) are compounded by operational downtime for affected small-to-medium businesses. The primary sectors impacted include manufacturing, healthcare, and education, based on incident reports from security firms like Emsisoft.

🛡️ Mitigation

Defenses include maintaining offline backups, enforcing least-privilege access, and blocking known IOCs such as the ransom note filename and email addresses ([email protected]). Organizations should deploy endpoint detection rules for .loo extensions and use email security gateways to filter phishing attachments. No official patch is needed since LooCipher exploits no vulnerability—user awareness and backup policies are the primary mitigations.

ⓘ 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.