How credential stealers extract browser passwords, cookies, and sessions using DPAPI
Infostealers collect credentials from browsers, applications, and files, then exfiltrate everything to the attacker. Modern variants target Chrome/Firefox passwords (via DPAPI), Discord tokens (LocalStorage), cryptocurrency wallets, session cookies, and system information. The data is compressed, exfiltrated over HTTPS or Telegram, and used immediately or sold. Runtime is typically under 60 seconds — often gone before AV responds.
Full reverse engineering walkthrough — ABE bypass via DLL injection, Chrome v20/v21 differences, live HTTP exfiltration demo.
In the video I said BIP32 — it should be BIP39 (mnemonic seed phrases).
An infostealer is malware that steals your saved passwords, browser cookies, and login sessions. When you click "Remember Me" on Netflix, your browser saves that login. Infostealers grab all of those saved logins and send them to an attacker.
Why should you care? If you've ever saved a password in Chrome, Edge, or Firefox - an infostealer can steal it in under 10 seconds. Your email, bank, social media, everything. The attacker doesn't need to "hack" anything - they just read what your browser already saved.
Your browser encrypts saved passwords so other programs can't read them. But here's the catch: any program running as YOU can decrypt them. Windows trusts that if you're logged in, you're allowed to see your own passwords.
So when you run a malicious .exe (disguised as a game crack, free software, or PDF), it runs as you. It can ask Windows "hey, decrypt these passwords please" and Windows says "sure, you're the owner." Game over.
What happens: A fake "Windows Update" or "Scanning..." screen appears fullscreen. You can't click away.
Why: While you're staring at that fake screen, the malware is stealing your passwords in the background. The screen exists to stop you from closing the program before it finishes.
"Installing updates... Do not turn off your PC"
What happens: The malware asks Windows to decrypt your browser's master password key.
Why this works: Windows uses something called DPAPI to protect passwords. But DPAPI was designed so YOU can access your own data - and any program running as you counts as "you."
CryptUnprotectData() → Master Key
What happens: Chrome stores all your saved passwords in a file called "Login Data." The malware copies this file and decrypts every password inside.
The scary part: This file contains EVERY password you ever clicked "Save" on. Gmail, Facebook, your bank - all in one place.
SELECT origin_url, username, password FROM logins
What happens: Your passwords get sent to the attacker via Discord webhook, Telegram bot, or a random web server.
Speed: This entire process takes 5-15 seconds. By the time the fake "update" screen closes, your passwords are already in the attacker's hands.
POST → discord.com/api/webhooks/...
Look in %LOCALAPPDATA%\Google\Chrome\User Data - this folder has everything
The file "Local State" has your encrypted master key - the key that unlocks all your passwords
Call CryptUnprotectData() - Windows will decrypt it because you're the logged-in user
Each saved password is encrypted with AES. Now we have the key, so we decrypt them all
Package everything (sites, usernames, passwords) and POST to Discord/Telegram webhook
Use a password manager like Bitwarden or 1Password instead. They don't store passwords in a way infostealers can grab.
Game cracks, "free" software, PDFs from strangers - these are how infostealers spread. If it's too good to be true, it's malware.
Even if they steal your password, 2FA stops them from logging in. Use an authenticator app, not SMS.
Infostealers also steal session cookies (logged-in sessions). Log out of important accounts periodically to invalidate old sessions.
Lab demo: DPAPI + AES-GCM extraction against a test environment. Chrome Local State decryption → Login Data SQLite → live exfil. MITRE T1555.003.
Most security education is written for security people. This page exists because everyone deserves to understand how their passwords can be stolen - so they can protect themselves. Knowledge isn't dangerous; ignorance is.