How We Caught a Data Stealing, Stealthy RAT in the Act

Overview

In a recent engagement, our cyber threat team encountered one of the stealthiest Remote Access Trojans (RATs) we’ve seen to date. 🕵️ This RAT didn’t behave like the typical noisy malware. It was calculated — surfacing only at specific intervals, exfiltrating data in tiny encrypted chunks, then vanishing into thin air. It ignored traditional scans and stayed completely dormant under active probing. We knew it was there — we just couldn’t see it… yet. So, we changed the game.

Challenge

• Key Characteristics:
• ❌ No response to pings or active scans.
• 📉 Low-and-slow data exfiltration tactics.
• 🕑 Timed callbacks to avoid detection.
• 🕳️ Hid in memory, no disk artifacts.

Solution

• ⚠️ We built custom honeypots and set behavioral traps. Instead of chasing the RAT, we baited it — creating fake data and simulated user activity that it couldn't resist. And it worked.

Results

🐀 When the RAT came alive again, it took the bait. We traced its callback mechanism, isolated its Command & Control (C2) infrastructure, and finally eradicated it from the client environment.