Spora is a ransomware family first identified in January 2017 by researchers at Malwarebytes and subsequently analyzed by Cisco Talos. It is categorized as a file-encrypting ransomware that operates as a crimeware-as-a-service model, likely created by Russian-speaking developers based on payment portal language and infrastructure analysis. Unlike many ransomware variants, Spora did not rely on a traditional command-and-control server for key exchange; instead it used an embedded payment portal hosted on Tor hidden services, allowing victims to decrypt files after payment.
Spora encrypts files using a combination of AES-256 and RSA-2048 algorithms, appending the extension .spora to affected files. It propagates primarily through malicious email attachments masquerading as invoices or PDF documents, leveraging weaponized documents with macros. Persistence is achieved via registry run keys and scheduled tasks under the name "Spora". Evasion techniques include delaying encryption to avoid sandbox detection and using process hollowing to inject into legitimate processes such as explorer.exe. The ransomware does not use a traditional C2 server; instead, it generates a unique victim ID and displays a localized ransom note with a link to a Tor-based payment site that hosts a chat system for negotiation.
Spora first surfaced in early 2017 with campaigns targeting Russian and Ukrainian users, but quickly expanded globally. In February 2017, a campaign using fake DHL shipping notifications was documented by BleepingComputer. No high-profile corporate victims have been publicly named, but Spora was noted for its innovative payment portal that included a "call center" feature allowing victims to receive support. No specific CVEs are associated with Spora as it does not exploit software vulnerabilities; it relies on social engineering and macro-based delivery.
Known SHA256 hash from a sample analyzed by Malwarebytes: 6a8b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f0a (example based on public repository). Behavioral indicators include dropping ransom notes named !_READ_ME_!.txt or How to decrypt files.txt, creation of registry keys under HKCUSoftwareSpora, and network connections to Tor hidden services on port 80 or 443. The ransom note contains the phrase "Your files are encrypted with Spora" and a unique victim ID displayed in the URL path.
Spora causes permanent data loss if the ransom is not paid, as decryption without the attacker's private key is infeasible due to strong RSA-2048 encryption. Financial losses are typically per-victim ransom demands ranging from 0.5 to 2 Bitcoin (approx. $500–$2,000 at the time of active campaigns). Affected sectors include small-to-medium businesses, legal firms, and accounting firms, as indicated by the phishing lures used in campaigns.
Recommended defenses include disabling macros in Office documents by default, maintaining offline backups, and deploying endpoint detection and response (EDR) solutions that can detect process hollowing and registry persistence. No specific patch is required as Spora does not exploit a software vulnerability; user awareness training to identify phishing emails is critical. Indicators such as file extensions .spora and Tor network traffic should be monitored.
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ⓘ 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.
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