Could the ‘Angry Magpie’ save your business from insider threat and data-related attacks?

DGIX

April 28, 2025

Browsers are the new frontline, but today’s DLP can’t see the real threats
Data Splicing Attacks break through enterprise browser security
Angry Magpie reveals how fragile the current DLP architecture is in a browser-first world

A newly uncovered data exfiltration technique known as Data Splicing Attacks could place thousands of businesses worldwide at significant risk, bypassing all leading data loss prevention (DLP) tools.

Attackers can split, encrypt, or encode data within the browser, transforming files into fragments that evade the detection logic used by both endpoint protection platforms (EPP) and network-based tools – before these pieces are then reassembled outside the protected environment.

By using alternative communication channels such as gRPC and WebRTC, or secure messaging platforms like WhatsApp and Telegram, threat actors can further obscure their tracks and avoid SSL-based inspections.

Threat actors now splice, encrypt, and vanish

The growing reliance on browsers as primary work tools has increased exposure. With more than 60% of enterprise data stored on cloud platforms accessed via browsers, the importance of a secure browser has never been greater.

Researchers demonstrated that proxy solutions used in many secure enterprise browsers simply cannot access the necessary context to recognize these attacks because they lack visibility into user interactions, DOM changes, and browser context.

Additionally, endpoint DLP systems struggle because they rely on APIs exposed by the browser, which do not offer identity context, extension awareness, or control over encrypted content.

These limitations create a blind spot that attackers can exploit without detection, undermining many enterprises’ ability to defend against insider threat scenarios.

What makes this discovery even more urgent is the ease with which these techniques can be adapted or modified. With new code, attackers can easily create variants, further widening the gap between evolving threats and outdated protections.

In response, the team introduced Angry Magpie, an open source toolkit designed to replicate these attacks. Security teams, red teams, and vendors can use the tool to evaluate their defenses.

Angry Magpie allows defenders to assess their systems’ exposure in realistic scenarios, helping identify blind spots in current implementations of even the best DLP solutions.

“We hope our research will serve as a call to action to acknowledge the significant risks browsers pose for data loss,” the team said.