ESET discovers PromptLock, the first AI-powered ransomware
Created: 2025-09-02 08:50:05
- ESET Research discovers PromptLock, a new type of ransomware using GenAI to execute attacks.
- The malware runs a locally accessible AI language model to generate malicious Lua scripts in real time, which are compatible across Windows, Linux, and macOS.
- PromptLock uses a freely available language model accessed via an API, meaning the generated malicious scripts are served directly to the infected device.
- Based on predefined text prompts, PromptLock autonomously determines whether to exfiltrate or encrypt data.
- While ESET considers PromptLock a proof of concept, the threat it represents is very real.
BRATISLAVA — August 27, 2025 — ESET researchers have uncovered a new type of ransomware that leverages generative artificial intelligence (GenAI) to execute attacks. Named PromptLock, the malware runs a locally accessible AI language model to generate malicious scripts in real time. During infection, the AI autonomously decides which files to search, copy, or encrypt — marking a potential turning point in how cybercriminals operate.
“The emergence of tools like PromptLock highlights a significant shift in the cyber threat landscape,” said Anton Cherepanov, senior malware researcher at ESET, who analyzed the malware alongside fellow researcher Peter Strýček.
PromptLock creates Lua scripts that are compatible across platforms, including Windows, Linux, and macOS. It scans local files, analyzes their content, and — based on predefined text prompts — determines whether to exfiltrate or encrypt the data. A destructive function is already embedded in the code, though it remains inactive for now.
The ransomware uses the SPECK 128-bit encryption algorithm and is written in Golang. Early variants have already surfaced on the malware analysis platform VirusTotal. While ESET considers PromptLock a proof of concept, the threat it represents is very real.
“With the help of AI, launching sophisticated attacks has become dramatically easier — eliminating the need for teams of skilled developers,” added Cherepanov. “A well-configured AI model is now enough to create complex, self-adapting malware. If properly implemented, such threats could severely complicate detection and make the work of cybersecurity defenders considerably more challenging.”
PromptLock uses a freely available language model accessed via an API, meaning the generated malicious scripts are served directly to the infected device. Notably, the prompt includes a Bitcoin address reportedly linked to Bitcoin creator Satoshi Nakamoto.
ESET has published technical details to raise awareness within the cybersecurity community. The malware has been classified as Filecoder.PromptLock.A.
Make sure to follow ESET Research on Twitter (today known as X), BlueSky, and Mastodon for the latest news from ESET Research.
About ESET
ESET develops software solutions that deliver instant, comprehensive protection against evolving computer security threats. ESET pioneered and continues to lead the industry in proactive threat detection. ESET NOD32 Antivirus, its flagship product, consistently achieves the highest accolades in all types of comparative testing and is the foundational product that builds out the ESET product line to include ESET Smart Security. ESET Smart Security is an integrated antivirus, antispyware, antispam and personal firewall solution that combines accuracy, speed and an extremely small system footprint to create the most effective security solution in the industry. Both products have an extremely efficient code base that eliminates the unnecessary large size found in some solutions. This means faster scanning that doesn’t slow down computers or networks. Sold in more than 160 countries, ESET has worldwide production headquarters in Bratislava, SK and worldwide distribution headquarters in San Diego, U.S. ESET also has offices in Bristol, U.K.; Buenos Aires, AR; Prague, CZ; and is globally represented by an extensive partner network. For more information, visit our local office at https://eset.version-2.sg.
About Version 2 Limited
Version 2 Limited is one of the most dynamic IT companies in Asia. The Company develops and distributes IT products for Internet and IP-based networks, including communication systems, Internet software, security, network, and media products. Through an extensive network of channels, point of sales, resellers, and partnership companies, Version 2 Limited offers quality products and services which are highly acclaimed in the market. Its customers cover a wide spectrum which includes Global 1000 enterprises, regional listed companies, public utilities, Government, a vast number of successful SMEs, and consumers in various Asian cities. For more information, please visit https://www.version-2.com.sg/ or call (65) 6296-4268.
Join ESET at Facebook