Varonis Shifts Left With Interceptor

December 12, 2025

Varonis acquired SlashNext in 2025 to bring its AI-native email and browser messaging protection into the Varonis platform as Varonis Interceptor so organizations can stop modern social engineering before it turns into identity misuse and data access. From here on, we will just call it Interceptor.

Why Interceptor Matters

Attackers use email to get to identity, and identity to get to data. Interceptor moves Varonis left in the MITRE ATT&CK chain from protecting data and responding to incidents to preventing initial access and pre‑credential theft. The result isn’t merely fewer bad emails, it’s a more resilient program. Interceptor’s high‑fidelity signals raise the priority of investigations and accelerate response across the Varonis ecosystem, including their managed data detection and response (MDDR) service. Think of it like a bank robbery story: Varonis has long guarded the vault (sensitive data), watched the cameras (identity and activity analytics), automated least privilege and coordinated the response team (MDDR). Interceptor is the reinforced front door and the guard who spots the disguise before the robber even steps in.

Interceptor detections do not live in a silo; they drive faster decisions resulting in fewer user‑reported phishing incidents, less security operations center (SOC) triage and clearer reporting for executives and boards. There is no rip‑and‑replace. Interceptor complements Microsoft Defender and existing secure email gateways, adding an AI‑native layer designed to catch evasive business email compromise (BEC), QR/image‑only lures and link‑less social engineering that legacy controls miss.

Crucially, Varonis with Interceptor provides visibility a gateway can’t. It analyzes internal (East–West) email abuse and stops live phishing even when links arrive via Teams, Slack, shared docs or locally hosted pages that reputation‑based tools won’t see. The net effect is earlier protection with richer context feeding your data and identity defenses.

Where Interceptor Fits

Interceptor adds initial access coverage with multimodal AI that spots BEC, payment-fraud, QR/image-only lures and pixel-perfect fake logins, and it brings browser-time blocking to stop live phishing, including locally hosted traps. Coverage spans inbound and internal email. Varonis then takes those signals and applies them across the platform to prioritize risk and drive outcome-focused response.

Recent research highlights two evasive trends Interceptor was built to counter. First, multi‑hop URL rewriting chains that borrow trust from well‑known vendors can slip past allowlists unless the final destination is analyzed by a virtual browser that follows every redirect. Second, SVG attachments can hide obfuscated JavaScript in CDATA blocks to overlay fake sign‑ins or trigger credential redirects the moment the image is rendered. Interceptor’s vision‑driven sandboxing, browser‑time blocking and behavior‑aware analysis address both, catching what legacy rewriting and extension‑only filters often miss.

The Platform, Unified

Sensitive mailbox data remains a prime target. Varonis already classifies mailbox content and highlights high‑value mailboxes to reduce exposure. The platform maps mailbox permissions (read, send‑as, send‑on‑behalf, shared mailboxes and external guests) so if a BEC campaign hits a delegate or shared mailbox with broad access, Varonis can predict blast radius and guide (or automate) risk reduction while the incident is live.

With Interceptor, when a phish targets owners of those mailboxes (think finance, HR, legal or executives) incidents are prioritized automatically and guardrails like rule removal, share lockdowns and closer watching for burst reads kick in sooner.

On forensics, Varonis already unifies evidence of mailbox activity, rules, anomalous sends and mass‑read events. Interceptor links the lure to the artifacts such as the initial message, URL or QR code to downstream rules, logins and mailbox access so responders tell a complete story:

“Here’s how they tried to get in → here’s what we blocked/removed → here’s what data they didn’t get.”

Additionally, and beyond email, Varonis finds risky OAuth apps, public links and overshared files across cloud apps. When credentials are the target, the platform hunts and revokes rogue OAuth grants and risky sharing links (the post‑phish backdoors attackers rely on) while MDDR begins earlier in the chain with richer context (attack type, lure path, target sensitivity) to execute outcome‑focused actions.

Shifting Left With MITRE ATT&CK: The Combined Value

Varonis’ combined stack lets you intervene earlier at Initial Access, follow through into Credential Access and Valid Accounts and limit blast radius during Discovery, Collection and Exfiltration. The table below summarizes how Interceptor’s signals hand off to Varonis’ identity and data controls in each phase.

In Practice: Killing the Lure Early

Here’s how this plays out in the real world. An invoice fraud email lands in an Accounts Payable inbox with no links, just an “urgent payment change”. Interceptor reads the tone and context, recognizes a BEC pattern and removes the message before anyone can act. Because the target owns sensitive financial mailboxes, Varonis automatically treats the event as higher risk and immediately checks for telltale fallout: newly created forwarding rules, unusual sign-ins or burst reads against those mailboxes. If any artifacts appear, MDDR moves from detection to action disabling the rule, killing sessions and temporarily tightening permissions. Finally, a clear incident narrative and evidence are delivered to the right escalation recipients.

In short, the lure dies at the door, the account stays yours and the data never moves.

Deployment, Evaluation and Day-to-Day

Today, Interceptor protects inbound and internal mail via API and extends protection to the browser and covers clicks from email, collaboration apps and even local pages. Spam and bulk reduction are included to reduce inbox noise and improve productivity. Interceptor supports your existing products in place like Microsoft Defender or your SEG to bring your phishing protection to the highest efficacy level in the market. Today, Interceptor is focused deeply on Microsoft 365 environments and will look to add support for other platforms as time moves forward.

Deployment is API‑based and takes minutes. There are no MX or gateway changes, and no mail‑flow reroutes. Once connected, Interceptor baselines the email tenant and begins protecting inbound and internal mail. A browser extension that supports all major browsers (e.g., Chrome, Edge) is also deployed to add real‑time page blocking for phishing sites, including locally hosted pages or links reached from non‑email channels.

Evaluations combine a six‑month historical lookback with live, read‑only monitoring. The lookback surfaces QR, image‑only and social engineering threats your current stack left in inboxes. Additionally, live monitoring shows how active campaigns are handled in production, without making policy changes during the trial. Upon completion, you will receive an executive summary along with several detailed artifacts that clearly demonstrate the findings and their underlying causes.

Day to day, Interceptor is low‑touch. Detections and policy actions run quietly; SOC triage drops as fewer users report suspected phishing and teams publish board‑friendly reports on a monthly or quarterly cadence. Because Interceptor feeds context into Varonis, responders start earlier in the kill chain with richer signals and close incidents faster with less noise.

Conclusion

This isn’t ‘another email tool’. Interceptor turns email and browsing into first‑class telemetry for a data‑centric security program and lets you act earlier in the kill chain. Its integration into the Varonis ecosystem results in full inbox‑to‑data coverage. Attackers’ methods of gaining access, attempting to log in and pursuing their targets are blocked at every stage.

Try Interceptor today. Reach out to your Optiv Client Manager for a complimentary risk assessment and evaluation!