🕵️ InfoStealers: The Silent Data Thieves
What Are InfoStealers?
InfoStealers are a class of malware designed to silently extract sensitive data from an infected system. Unlike ransomware, which locks files and demands payment, InfoStealers operate covertly, stealing data without the user’s knowledge.
🔹 Primary Targets:
✅ Login credentials (banking, emails, corporate accounts)
✅ Session cookies (to bypass Multi-Factor Authentication - MFA)
✅ Saved credit cards from browsers
✅ Cryptocurrency wallets (MetaMask, Exodus, Trust Wallet)
✅ System data (IP address, OS, installed software, and browser history)
How InfoStealers Work
1️⃣ Infection → Delivered through phishing emails, malicious ads, cracked software, or fake browser updates.
2️⃣ Data Extraction → Steals passwords, session cookies, crypto wallets, and more from browsers and applications.
3️⃣ Exfiltration → Sends stolen data to cybercriminals via command & control (C2) servers.
4️⃣ Exploitation → Attackers can:
- 📛 Sell credentials on dark web marketplaces.
- 📌 Hijack accounts and bypass MFA using stolen session cookies.
- 💰 Access banking data and drain financial accounts.
- 🏢 Use stolen credentials for corporate breaches and ransomware deployment.
🚨 Most Active InfoStealers in 2024
| InfoStealer | Infections Detected | Key Features |
|---|---|---|
| RedLine | 15.6M+ | Most widespread; steals credentials, cookies, crypto wallets |
| Lumma | 4.2M+ | Rapidly evolving, hard to detect |
| Raccoon | 3M+ | Focuses on banking and credit card theft |
| StealC | 1.1M+ | Advanced evasion techniques |
| Vidar | 1M+ | Targets corporate credentials & crypto wallets |
| Azorult | 832K+ | Still active despite age, steals system and browser data |
| Mystic | 55K+ | High-end stealer, focuses on corporate users |
🔬 Case Study: RedLine Stealer
- Unmasking RedLine Stealer - Idan Malihi, Medium - Very interesting
🔴 RedLine is the most widely used InfoStealer, primarily sold on underground forums and Telegram groups.
Infection Process
- User downloads a fake file (e.g., cracked software, a phishing email attachment, or a malicious ad).
- Stealer runs silently in the background, avoiding detection.
- Steals data from browsers, including passwords, cookies, and autofill information.
- Uploads stolen data to a C2 server, where attackers can use or sell it.
- Hackers exploit stolen credentials for fraud, ransomware attacks, or corporate breaches.
⚠️ Why Are InfoStealers So Dangerous?
🔹 Bypass MFA
Stolen session cookies allow attackers to access accounts without needing a password or second factor.
🔹 Massive Credential Leaks
Data is sold on the dark web or used in corporate breaches.
🔹 Ransomware Deployment
Cybercriminals use stolen VPN or corporate logins to launch ransomware attacks.
🔹 Undetected for Long Periods
Many victims don’t realize they’ve been compromised until it’s too late.
🛡 How to Protect from InfoStealers
✔ Do NOT save passwords in browsers
Use Bitwarden or 1Password instead.
✔ Enable Multi-Factor Authentication (MFA)
Prefer hardware security keys (Yubikey) over SMS codes.
✔ Use a secure DNS & ad blocker
Block malicious ads & scripts.
✔ Avoid downloading software from unofficial sources
Use legitimate sites only.
✔ Monitor for compromised credentials