The PoSeidon malware, also known as FindPOS or FindStr, is a point-of-sale (POS) malware variant identified in version 15.10 and reported in mid-2019. This malware targets POS systems, which are critical components in retail and hospitality sectors for processing payment card transactions. PoSeidon operates primarily as a memory scraper, designed to extract sensitive payment card data directly from the memory of POS terminals during transaction processing. Additionally, it incorporates keylogging capabilities to capture user input, potentially harvesting credentials or other sensitive information entered via the keyboard. The malware is notable for being signed with a certificate issued by Thawte under the entity Lingarder Limited, which may help it evade some security detections by appearing as legitimate software. Despite its capabilities, there are no known exploits in the wild reported for this specific version, and the threat level is assessed as medium. The malware’s operation involves raw input capture and memory scraping, techniques that allow it to bypass some traditional file-based detection methods. The lack of specific affected versions and patches suggests that PoSeidon targets a range of POS systems without a particular vendor or software version focus, making it a generic threat to POS environments. The information is sourced from CIRCL and cataloged in malpedia, with an OSINT certainty rating of 50%, indicating moderate confidence in the data. Overall, PoSeidon represents a persistent threat to POS infrastructure by compromising payment card data confidentiality and potentially enabling financial fraud through stolen cardholder information.

For European organizations, particularly those in retail, hospitality, and any sector utilizing POS systems, PoSeidon poses a significant risk to the confidentiality of payment card data. A successful infection can lead to large-scale theft of cardholder data, resulting in financial losses, regulatory penalties under GDPR and PCI DSS, and reputational damage. The malware’s ability to scrape memory and log keystrokes means that even encrypted or tokenized data might be at risk if processed in memory in cleartext. This threat could disrupt payment operations if detected and remediated, causing availability issues. Given the widespread use of POS systems across Europe and the stringent data protection regulations, an incident involving PoSeidon could trigger mandatory breach notifications and legal consequences. Furthermore, the theft of payment data can facilitate downstream fraud affecting both consumers and financial institutions. The medium severity rating reflects the malware’s potential impact balanced against the absence of known active exploits and the technical barriers to infection, such as the need for initial system compromise.

European organizations should implement targeted defenses to mitigate PoSeidon risks beyond generic advice. First, enforce strict application whitelisting on POS terminals to prevent unauthorized software execution, including malware signed with legitimate certificates. Deploy endpoint detection and response (EDR) solutions capable of monitoring memory scraping and keylogging behaviors, focusing on anomalous raw input capture and unusual process memory access patterns. Segment POS networks from other corporate networks to limit lateral movement and reduce exposure. Regularly update and patch POS software and underlying operating systems, even if no specific patches for PoSeidon exist, to close other vulnerabilities that could facilitate initial compromise. Employ hardware-based encryption and tokenization solutions that minimize the presence of cleartext card data in memory. Conduct frequent security audits and malware scans specifically targeting POS environments. Train staff on phishing and social engineering risks to reduce the likelihood of initial infection vectors. Finally, monitor threat intelligence feeds for updates on PoSeidon and related malware variants to adapt defenses promptly.