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1Scan for outdated or missing drivers - takes under a minute2Clear out junk files and repair common Windows errors3Fix the driver behind crashes, sound loss and screen glitchesPrompt Security raised an $18 million Series A in November 2024, led by Jump Capital, with Hetz Ventures, Ridge Ventures, Okta and F5 also participating. The round brought the company’s reported total funding to $23 million. The enterprise software company was later acquired by SentinelOne: the cybersecurity firm announced a definitive agreement in August 2025, with closing then projected for fiscal Q3 2026.
Who funded Prompt Security’s $18 million round?
SecurityWeek reported on November 22, 2024, that Jump Capital led the Series A. Hetz Ventures, Ridge Ventures, Okta and F5 also participated. Prompt Security’s November 20 announcement said the round brought its total funding to $23 million.
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The financing followed a $5 million seed round led by Hetz Ventures, with Four Rivers and cybersecurity-focused angel investors also participating. TechCrunch reported the seed alongside the company’s emergence from stealth in January 2024.
What does Prompt Security do?
Prompt Security develops security controls for organizations using generative AI. Its platform is intended to help companies see how employees and applications interact with AI tools, set usage policies, and respond to risks such as sensitive-data leakage, misuse and prompt injection. The company has described coverage spanning browsers, copilots, coding assistants, desktop applications, APIs and custom-built AI applications.
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The product addresses two related situations: employees using AI services that their organization has not approved, often called shadow AI, and organizations deploying their own AI applications without adequate safeguards. The platform is designed to govern both employee use and application workflows rather than securing only one chatbot or model.
How does it address shadow AI and prompt injection?
Discovering AI use
SentinelOne’s September 2025 product description says Prompt Security uses a lightweight agent and browser extensions to identify sanctioned and unsanctioned AI applications across browsers, desktop IDEs, terminal assistants, APIs and custom workflows. This visibility can help an organization understand where AI is being used before deciding which uses to permit or restrict.
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- POWERFUL SECURITY KEY: The YubiKey 5 NFC is the most versatile physical passkey, protecting your digital life from phishing attacks. It ensures only you can access your accounts
- WORKS WITH 1000+ ACCOUNTS: Compatible with popular accounts like Google, Microsoft, and Apple. A single YubiKey 5 NFC secures 100+ of your favorite accounts, including email, password managers, and more
- FAST & CONVENIENT LOGIN: Plug in your YubiKey 5 NFC via USB and tap it, or tap it against your phone (NFC), to authenticate. No batteries, no internet connection, and no extra fees required
- MOST SECURE PASSKEY: Supports FIDO2/WebAuthn, FIDO U2F, Yubico OTP, OATH-TOTP/HOTP, Smart card (PIV), and OpenPGP. That means it’s versatile, working almost anywhere you need it
- PRIMARY & SPARE KEYS: Just like having a spare house key, we recommend buying two YubiKeys - one for daily use and one as a spare. That way you’ll never get locked out of your accounts
Applying policies and data controls
SentinelOne says the platform can apply policy-based controls in real time, including controls aimed at preventing sensitive information from being sent to AI services. Its acquisition announcement described model-agnostic coverage across major LLM providers and self-hosted models. These are product descriptions from the vendors, not independent measurements of prevention effectiveness.
Controlling agent and MCP interactions
SentinelOne describes an MCP Gateway that sits between AI applications and known MCP servers, intercepting calls, prompt templates and responses so controls can allow, block, filter or redact activity. The September 2025 materials cited more than 13,000 known MCP servers; that figure is a vendor claim.
Rank #3
- POWERFUL SECURITY KEY: The YubiKey 5C NFC is the most versatile physical passkey, protecting your digital life from phishing attacks. It ensures only you can access your accounts
- WORKS WITH 1000+ ACCOUNTS: Compatible with popular accounts like Google, Microsoft, and Apple. A single YubiKey 5C NFC secures 100+ of your favorite accounts, including email, password managers, and more
- FAST & CONVENIENT LOGIN: Plug in your YubiKey 5C NFC via USB and tap it, or tap it against your phone (NFC), to authenticate. No batteries, no internet connection, and no extra fees required
- MOST SECURE PASSKEY: Supports FIDO2/WebAuthn, FIDO U2F, Yubico OTP, OATH-TOTP/HOTP, Smart card (PIV), and OpenPGP. That means it’s versatile, working almost anywhere you need it
- PRIMARY & SPARE KEYS: Just like having a spare house key, we recommend buying two YubiKeys - one for daily use and one as a spare. That way you’ll never get locked out of your accounts
In 2026, SentinelOne announced an integration with Amazon Bedrock AgentCore. Prompt Security supplies signals related to prompt injection, personally identifiable information exposure, tool-use validation, response monitoring and data leakage. AgentCore’s policy engine applies deterministic allow-or-deny decisions outside the agent’s reasoning loop, according to the announcement. SentinelOne also said existing Prompt Security customers could use a bring-your-own-license path.
What happened after the funding?
On August 5, 2025, SentinelOne announced a definitive agreement to acquire Prompt Security for cash and stock, subject to regulatory approvals and customary closing conditions. At announcement, SentinelOne projected closing in fiscal Q3 2026. The announcement did not disclose a transaction value, and the available information here does not establish whether the acquisition subsequently closed.
Rank #4
- POWERFUL SECURITY KEY: The Security Key NFC is the essential physical passkey for protecting your digital life from phishing attacks. It ensures only you can access your accounts.
- WORKS WITH 1000+ ACCOUNTS: Compatible with Google, Microsoft, and Apple. A single Security Key NFC secures 100 of your favorite accounts, including email, password managers, and more.
- FAST & CONVENIENT LOGIN: Plug in your Security Key NFC via USB-A and tap it, or tap it against your phone (NFC) to authenticate. No batteries, no internet connection, and no extra fees required.
- TRUSTED PASSKEY TECHNOLOGY: Uses the latest passkey standards (FIDO2/WebAuthn & FIDO U2F) but does not support One-Time Passwords. For complex needs, check out the YubiKey 5 Series.
- BUILT TO LAST: Made from tough, waterproof, and crush-resistant materials. Manufactured in Sweden and programmed in the USA with the highest security standards.
Prompt Security CEO Itamar Golan said the company had dozens of enterprise customers, multiple Fortune 500 customers, millions of monthly AI interactions and multi-million-dollar annual recurring revenue. Those are company-reported figures, not independently audited statistics.
SentinelOne’s OneCon 2025 materials described Prompt Security offerings for employee GenAI usage, AI coding assistants and agentic AI. They claimed support for more than 15,000 AI sites in the employee-use offering, and highlighted visibility and governance for MCP-based agents. These figures and product capabilities should be understood as SentinelOne’s descriptions.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Company timeline
| Date | Milestone |
|---|---|
| August 2023 | Itamar Golan and Lior Drihem founded Prompt Security, according to Calcalist. |
| January 2024 | The company emerged from stealth after a $5 million seed round led by Hetz Ventures, TechCrunch reported. |
| November 2024 | Prompt Security announced an $18 million Series A led by Jump Capital; reported cumulative funding reached $23 million. |
| August 5, 2025 | SentinelOne announced a definitive agreement to acquire Prompt Security, with a projected fiscal Q3 2026 closing subject to conditions. |
| 2026 | SentinelOne announced Prompt Security signal integration with Amazon Bedrock AgentCore. |
What the funding means for buyers
The round gave Prompt Security capital to develop protections and governance for enterprise GenAI use; its announcement specifically cited visibility and control across browsers, copilots, coding assistants and homegrown applications. It is not evidence by itself that the software prevents attacks or data leaks in every environment. Organizations evaluating an AI-security platform should compare the systems it covers, the policies it can enforce, and how controls are deployed across endpoints, browsers, gateways and APIs.
Quick Recap
- Coverage: Check whether the product observes the browsers, IDEs, APIs, custom apps and AI agents employees actually use.
- Controls: Confirm which actions can be allowed, blocked, filtered or redacted, and whether policies operate in real time.
- Threat scope: Ask how the product handles prompt injection, sensitive-data exposure, misuse and agent tool-use risk.
- Model and deployment fit: Validate support for commercial and self-hosted models, and the endpoint, extension, gateway or API integrations your architecture requires.
- Evidence: Separate vendor-reported coverage and customer figures from independently verified security outcomes.
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