Malicious Chromium Extension Spoofs Perplexity AI to Hijack Browser Searches
What Happened — Researchers at Microsoft discovered a Chromium‑based browser extension that masquerades as the AI‑powered answer engine Perplexity AI. The extension uses Manifest V3 APIs to silently redirect users’ search queries to attacker‑controlled infrastructure, harvesting search terms and potentially steering victims to phishing sites.
Why It Matters for Compliance & Audit Readiness
- SOC 2 CC6.1 (System Operations) requires documented controls for third‑party software and continuous monitoring of endpoint assets; a rogue extension bypasses those controls.
- Access‑control policies (CC5.1) must cover browser‑level privileges, ensuring only approved extensions can run.
- Security Awareness Training (CC1.2) is a core defense against social‑engineering vectors that rely on trusted‑looking UI cues.
Who Is Affected – Any organization that allows employees to install Chrome/Edge extensions, spanning technology SaaS, financial services, healthcare, and retail.
Recommended Actions –
- Conduct an inventory of all installed browser extensions and enforce an allow‑list.
- Update endpoint‑security policies to block unsigned or unvetted extensions.
- Incorporate extension‑review logs into your continuous‑compliance evidence pipeline.
- Refresh security‑awareness curricula to highlight “AI‑branding” phishing tactics.
Source: Microsoft Security Blog
Technical Notes – The malicious add‑on leverages MV3 background service workers, intercepts chrome.search calls, and forwards queries to a remote server that returns fabricated search results. No public CVE is associated, but the technique demonstrates how legitimate extension APIs can be abused.
Source: same as above